Smart headphone system and method

Abstract

By utilizing the existing speaker drivers associated with the dam headphones, smart headphone functionality is enabled without the need for additional auxiliary sensors, providing a peripheral device that excels in terms of weight, volume, cost, and power consumption. [Solution] The zeroing circuit 300, which selectively couples to the magnetic coil driver of the headset, includes a Wheatstone bridge that detects minute fluctuations in the headphone driver voltage caused by the excitation signal, thereby zeroing out the electrical energy associated with the audio input signal. This provides an output signal that mainly consists of the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to external pressure applied to the diaphragm.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims the interests of U.S. Provisional Patent Application No. 63 / 029,016, filed on 22 May 2020, and incorporates that application in its entirety herein by reference.

[0002] This disclosure generally relates to headphones, and more particularly to sensing diaphragm pressure excitation energy received from headphones, and supporting additional headphone functions and applications thereof. [Background technology]

[0003] This section is intended to introduce readers to various aspects of the technology, which may relate to various aspects of the invention described and / or claimed below. This discussion is intended to provide readers with background information to help them better understand the various aspects of the invention. Therefore, these descriptions should be read in this context and not as an endorsement of prior art.

[0004] Smart headphones generally include headphones with a microphone and various auxiliary sensors that support applications such as user authentication, heart rate monitoring, touch gesture control, and voice communication. Auxiliary sensors (e.g., accelerometers, gyroscopes) increase the weight, volume, cost, and power consumption of smart headphones, hindering consumer adoption of such headphones. Furthermore, reliance on auxiliary sensors makes it difficult to transfer the design to commercially available headphones that do not have the necessary sensors. [Overview of the Initiative]

[0005] Various shortcomings of the prior art are addressed by systems, methods, architectures, mechanisms, and apparatus that provide a sensing platform, in which one or more headphone drivers are used as general-purpose sensors, from which excitation signals indicating direct or indirect pressure related to the ear canal are received, in acoustic cooperation with a diaphragm operably coupled to the driver.

[0006] Various embodiments can be used to interpret the received excitation signal(s) and identify within them voice information (voice detection), gesture information (gesture detection), unique human identification information (user identification), heart rate and / or respiratory rate information (physiological information), etc. In this way, new applications can be provided within contexts such as mobile health, user interface, context awareness, and identification / authentication.

[0007] Various embodiments can be implemented as plug-in peripherals connecting headphones to a pairing device (e.g., a user device such as a smartphone or computer), or as integrated circuits built into headphones or a pairing device.

[0008] One embodiment comprises a device for receiving information from a headset, the headset comprising a magnetic coil driver operably coupled to a diaphragm, the magnetic coil driver configured to receive an audio input signal and, in response thereto, generate air vibrations in the diaphragm corresponding to the audio input signal, the device comprising a zeroing circuit configured to be selectively coupled to the magnetic coil driver to zero out the electrical energy associated with the audio input signal, thereby providing an output signal mainly comprising the electrical energy associated with an excitation signal generated by the magnetic coil driver in response to an external pressure applied to the diaphragm, and an amplifier circuit configured to amplify the output signal of the zeroing circuit, thereby providing an amplified excitation signal that enables determination of the external pressure applied to the diaphragm.

[0009] Additional objects, advantages, and novel features of the present invention are partially set forth in the following description and may become apparent to those skilled in the art through the following considerations or may be acquired through the practice of the present invention. The objects and advantages of the present invention may be realized and achieved by means and combinations specifically indicated in the appended claims. [Brief explanation of the drawing]

[0010] The accompanying drawings incorporated herein and constituting part thereof illustrate embodiments of the present invention and, together with the above general description of the invention and the following detailed description of embodiments, are useful in illustrating the principles of the present invention.

[0011] [Figure 1] Figures 1A and 1B illustrate the structural components of the human ear and their 2-port Thevenin equivalent network representations.

[0012] [Figure 2] Figures 2A–2C graphically show exemplary time-domain excitation signals for speech, gestures, and music.

[0013] [Figure 3] Figure 3 shows a schematic diagram of an exemplary zeroing circuit suitable for use in various embodiments.

[0014] [Figure 4] Figure 4 shows a schematic diagram of the apparatus according to one embodiment.

[0015] [Figure 5] Figure 5 shows a high-level block diagram of a user device suitable for use in various embodiments.

[0016] [Figure 6] Figure 6 shows flowcharts of the method according to various embodiments.

[0017] [Figure 7]Figures 7A and 7B show graphs of the channel responses measured for three different people responding to an audio chirp signal.

[0018] [Figure 8] Figures 8A-8D show the measured channel responses for touch gestures in graph form.

[0019] [Figure 9] Figure 9 shows a schematic diagram of the apparatus according to one embodiment.

[0020] [Figure 10] Figure 10 shows a flowchart of the method according to one embodiment.

[0021] [Figure 11] Figure 11 shows a schematic diagram of an apparatus according to one embodiment.

[0022] [Figure 12] Figure 12 shows a schematic diagram of an apparatus according to one embodiment.

[0023] It should be understood that the accompanying drawings are not necessarily to a constant scale and represent various features illustrating the basic principles of the present invention in a somewhat simplified manner. Certain design features of the series of operations disclosed herein include, for example, specific dimensions, orientations, positions, and shapes of various illustrated components, and are partly determined by the specific intended use and operating environment. Certain features of the illustrated embodiments are enlarged or distorted relative to others to facilitate visualization and clear understanding. Specifically, for example, thin shapes may be thickened for clarity or illustration. [Modes for carrying out the invention]

[0024] The following description and drawings merely illustrate the principles of the present invention. Therefore, those skilled in the art will understand that various configurations embodying the principles of the present invention and falling within its scope can be devised, although these are not explicitly described or illustrated herein. Furthermore, all examples detailed herein are primarily intended, and obviously, for educational purposes only, to help the reader understand the principles of the present invention and the concepts to which the inventors have contributed to advancing the art, and should be interpreted as not being limited to such particularly detailed examples and conditions. Furthermore, the term “or” as used herein refers to a non-exclusive “or” unless otherwise explicitly stated (e.g., “or otherwise” or “or instead”). Also, since several embodiments can be combined with one or more other embodiments to form new embodiments, the various embodiments described herein are not necessarily mutually exclusive.

[0025] Numerous innovative teachings of this application are described with particular reference to currently preferred exemplary embodiments. However, it should be understood that embodiments of this class provide only a few examples of the many advantageous applications of the innovative teachings herein. In general, the descriptions made in the specification of this application are not necessarily limited to any of the various claimed inventions. Furthermore, some descriptions may apply to some inventive features and not to others. A person skilled in the art who has been informed by the teachings herein will understand that the invention is applicable to a variety of other arts or embodiments.

[0026] Various embodiments provide systems, apparatus, and methods for implementing smart headphones in a cost-effective manner, as well as kits suitable for converting dumb headphones (audio output only) into smart headphones.

[0027] Advantageously, rather than using auxiliary sensors to implement smart headphone functionality, various embodiments utilize existing speaker drivers associated with a pair of dumb headphones to enable smart headphone functionality. Furthermore, various embodiments may include plug-in peripherals for non-intrusively connecting existing headphones to a pairing device (e.g., a user device such as a smartphone or computer), thereby avoiding hardware modifications or customizations that might add weight / bulk or require access to internal circuit design and external structure / integrity of the dumb headphones. Moreover, various implementations offer relatively low-cost peripherals with minimal power consumption on both the headphones and the pairing device.

[0028] All headphones convert electrical energy into sound using a magnetic coil that drives a diaphragm to vibrate the air. The voltage measured in each driver is determined by three factors: specifically, the electrical energy of the audio input signal received via wired, Bluetooth®, or other means (such as music played through the headphones), the equivalent impedance of the driver, and the air pressure in the corresponding diaphragm.

[0029] Part of the inventor's contribution lies in recognizing that new functions can be realized by utilizing the coupling effect between headphones and their surroundings. For example, when a user wears headphones, the headphones, ear canal, and eardrum are coupled together, forming a semi-sealed space that is highly sensitive to pressure changes. Pressure changes can be induced externally, even by something as quiet as touching the headphones, or by vibrations of the headphones caused by external sounds and / or vibrations. Similarly, internal physiological activities of the headphone wearer, such as heart rate, cause repetitive deformation of blood vessels in the ear canal, which alters the pressure within the semi-sealed space. Given that humans have ear canals of relatively unique size and shape, this uniqueness gives rise to new modalities for human identification, and such modalities are implemented in several embodiments.

[0030] Therefore, since the voltage associated with the speaker driver of headphones is affected by pressure changes within the human ear canal, this voltage change can be used to detect not only external changes (e.g., sound, touch, etc.) but also subtle internal physiological changes (e.g., heart rate, etc.). In this way, various embodiments also find usefulness in contexts such as mobile health, user interfaces, user authentication, and context awareness.

[0031] Figures 1A and 1B illustrate the structural components of the human ear and their 2-port Thevenin equivalent network representations, respectively. When a user puts on their headphones, the headphones cover the user's inner ear in a semi-closed state, as shown in Figure 1A, and the headphones, ear canal, and eardrum are coupled together (acoustically cooperate), thereby establishing a pressure field that can be modeled by a two-port Thevenin equivalent network shown in Figure 1B. The variables of the two-port Thevenin equivalent network are defined as follows:

[0032] P headphones Thevenin pressure of headphones.

[0033] Z headphones: Equivalent impedance of the headphones.

[0034] P eardrum : Tympanic membrane pressure.

[0035] Z eardrum : Equivalent impedance of the tympanic membrane

[0036] P earcanal : External auditory canal pressure.

[0037] Z earcanal : Equivalent impedance of the external auditory canal.

[0038] The Z in this model x and the pressure P x can be expressed by the following equation.

Equation

[0039] From the above equation, Z headphones is affected by the tympanic membrane pressure P eardrum which is affected by all excitation signals caused by humans, P earcanal , and the impedance Z earcanal . For example, when the user touches the housing of their headphones, this touch gesture causes the housing to vibrate, thus affecting the value of the tympanic membrane pressure P headphones . Similarly, physiological activities such as breathing and heartbeat cause repeated deformation of the blood vessels in the external auditory canal, changing the tympanic membrane pressure P earcanal . Also, since there are individual differences in the size and shape of the external auditory canal, there are individual differences in the impedance Z earcanal of the external auditory canal. Therefore, the electrical signal at the headphone driver (E headphones ) is affected by Z headphones , so various embodiments utilize E headphones to sense these interactions between humans and headphones and physiological activities.

[0040] Figures 2A–2C graphically illustrate exemplary time-domain excitation signals for speech, gestures, and music. Specifically, Figure 2 shows typical headphone driver voltages E caused by different excitation signals. headphones The signals are shown graphically. Specifically, they represent a user speaking so that their voice is received by the headphone diaphragm (Figure 2A), a user lightly tapping their headphone housing with their finger (Figure 2B), and music being played through the headphones (Figure 2C). While the input music signal is on the order of several hundred millivolts, the voltage fluctuation caused by the user's speech is usually less than 1 millivolt, and the voltage fluctuation caused by the user tapping the headphones is 5 millivolts, as can be seen through careful examination.

[0041] To achieve sufficient measurement sensitivity and discrimination for speech (user voice), tapping (user gestures), and physiological sensing (user heart rate or respiration), various embodiments utilize passive zeroing circuits to substantially reduce or eliminate voltage fluctuations caused by the input music (audio) signal.

[0042] Figure 3 shows a schematic diagram of an exemplary zeroing circuit suitable for use in various embodiments. Specifically, the zeroing circuit 300 in Figure 3 exemplifies the headphone driver voltage E caused by the excitation signal. headphones It features a Wheatstone bridge configured to detect minute fluctuations.

[0043] Generally speaking, zeroing circuits such as Wheatstone bridges, given sensor resistance and temperature, determine the difference between a signal and a reference entirely by resistors with low noise (compared to active circuits using, for example, operational amplifiers). Wheatstone bridges are suitable for measuring small excitation signals and automatically remove any significant audio signals present (interference cancellation) at no additional cost.

[0044] The zeroing circuit 300 in Figure 3 comprises a Wheatstone bridge having two voltage divider arms coupled across a voltage source Vin (where Vin represents an audio signal). Specifically, the first voltage divider arm includes a resistor R1 and an adjustable impedance device RLC1 (e.g., an adjustable capacitor) connected in series in the order listed, and the second voltage divider arm includes a resistor R2 (substantially identical to R1) and an unknown impedance RLC1. X The headphone driver and the adjustable impedance device RLC1 and headphone driver RLC are connected in series in the order listed above. X The impedance or reactance of a device includes one or more of the following components: resistance (R), inductive (L), and / or capacitive (C).

[0045] The adjustable impedance device RLC1 has an impedance that allows for a "balanced" impedance bridge (under the condition R1=R2) to be achieved, and its impedance is such that it (under the condition R1=R2) X It is adjusted until it equals the impedance of the two loads. In this balanced state, the voltages of the two loads (the two voltage divider arms) are the same, and as a result the voltage output V O It becomes zero (measured between the non-common terminals of resistors R1 and R2). Headphone driver RLC X If the impedance of the headphone driver changes even slightly, the voltage across this load changes, disrupting the balance of the bridge and causing the output voltage V to change. O It will no longer be zero.

[0046] During operation, the zeroing circuit 300 in Figure 3 receives an input voltage Vin containing an audio signal that has been balanced (zeroed out or substantially removed) via a Wheatstone bridge circuit or other zeroing circuit configuration. The headphone driver RLC forms part of the second voltage divider arm. XThis is part of a driver assembly that includes a magnet, voice coil, and diaphragm, which are operably connected in a standard way that converts electrical signals into audible signals / sound. Specifically, the driver (magnet and voice coil) works to drive the corresponding diaphragm, generating air vibrations corresponding to the audio input signal, thereby producing sound from the speaker containing that diaphragm to the headphone wearer. However, the audio signal also powers both voltage divider arms, thereby outputting a voltage V O Since it is set to zero, the voltage output V of the zeroing circuit O The voltage remains at zero volts or practically zero volts.

[0047] If the audio signal is zeroed out (effectively zeroed out or removed), the remaining electrical signal is due to the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to the external pressure applied to the diaphragm. That is, the zeroing circuit is configured to selectively couple to the magnetic coil driver to zero out the electrical energy associated with the audio input signal, thereby providing an output signal that primarily contains the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to the external pressure applied to the diaphragm. The output of the zeroing circuit provides an amplified excitation signal that can be amplified as needed and processed to determine the temporal and / or spectral components of the excitation energy, and thus the external pressure applied to the diaphragm required to produce such excitation energy can be determined.

[0048] The above-described single-speaker embodiment requires an impedance device RLC1 and a headphone driver RLC to function properly. X This requires precise impedance matching. If precise manufacturing standards are used to produce driver circuits such as magnetic coils, this impedance matching can be achieved in a manufacturable and scalable manner.

[0049] In various embodiments, the stringent manufacturing standards for such components for headphones are used to provide embodiments that require no adjustment whatsoever. That is, the impedance device RLC1 is used as the headphone driver RLC X Instead of matching the impedance device RLC1 and the headphone driver RLC X Herein, we describe a two-speaker embodiment in which each of the speakers fits into one of the left and right magnetic coil drivers used in standard headphones.

[0050] Figure 4 shows a schematic diagram of the apparatus according to one embodiment. Specifically, Figure 4 shows an excitation signal detector 400 coupled to a sound source (e.g., audio output of a user device via a 3.5mm plug, Universal Serial Bus (USB), Micro USB (uUSB), USB-C, Lightning, or other connector), a set of headphones (e.g., wired headphones with a 3.5mm plug, USB, uUSB, USB-C, Lightning, or other connector), and an audio receiver (e.g., audio input of a user device via a 3.5mm plug, USB, uUSB, USB-C, Lightning, or other connector).

[0051] The audio input signal is coupled to a zeroing circuit (e.g., a Wheatstone bridge as described above with respect to Figure 3) via an optional bypass switch S1. The two voltage divider arms consist of (1) a series component between R1 and the right speaker driver of the headphones, and (2) R2 and the left speaker driver of the headphones. Assuming a standard 50-ohm audio impedance matching, resistors R1 and R2 will each be 50-ohm resistors, but other values ​​can be used as long as R1 is substantially equal to R2. More generally, R1 and R2 are chosen to ensure that each of the voltage divider arms represents substantially similar impedances (i.e., RLC impedances).

[0052] The zeroing circuit zeros out the audio input signal, resulting in a differential voltage V representing the electrical energy associated with the excitation signal generated by the magnetic coil drivers (left and right) in response to the external pressure applied to the diaphragms (left and right). in + and V in- A differential voltage V is generated (between the junction of R1 / right driver and the junction of R2 / left driver). in + and V in- This is coupled to a precision amplifier AMP, such as the 1NA126 instrumentation amplifier, which in turn generates an output voltage signal that primarily represents the excitation signal energy, and this signal is coupled as an output signal OUTPUT via a second optional bypass switch S2.

[0053] 5000 ohm output resistor R L This can be used to trigger the microphone detection circuit of audio input devices such as smartphones and other user devices. Depending on the requirements of the various microphone detection circuits, a resistor R of a different value can be used. L You can also use (for example, 4.7kΩ).

[0054] The output signal can be provided to an audio receiver for further processing (e.g., to the audio input of a user device via a 3.5mm plug, USB, uUSB, USB-C, Lightning, or other connector for processing using an application or for digitization / transmission to a remote processing device).

[0055] In various embodiments, the amplifier circuit AMP is not used, and the differential voltage V in + and V in- This is shown as the output signal OUTPUT.

[0056] Note that the left and right headphone drivers are typically wired to be in phase for coherent stereo playback (AC signal). The left driver Eleft and right driver E are received by the zeroing circuit. right The voltage measured is the bridge voltage output Vg That's abnormal left -Er ight The difference (that is, V g =E left -E right They are phase-inverted from each other in a manner that characterizes them. In practice, the excitation signals are the left and right excitation signals E left and E right Each driver is reached via an unequal path, such that a small differential voltage exists for each of them.

[0057] In various embodiments, the apparatus described above comprises a standalone device comprising a housing (not shown) configured to mechanically support a zeroing circuit and an amplifier circuit, the housing having a first headphone connector configured to provide electromechanical coordination between the apparatus and a headphone device, and a second headphone connector configured to provide electromechanical coordination between the apparatus and an audio device. The first and second headphone connectors may be any of a 3.5mm plug, a Universal Serial Bus (USB) connector, a uUSB connector, a USB-C connector, and a Lightning connector. In such embodiments, any required power (e.g., +5V, -5V for the exemplary amplifier) ​​can be obtained from a battery in the housing (not shown) or from power received from the audio device to which the apparatus is connected. In some embodiments, additional power regulation circuitry may be required, such as deriving a -5V signal via a provided +5V signal.

[0058] In various embodiments, the apparatus described above with respect to Figure 4 comprises a device or module (e.g., an additional or modified integrated circuit) within a user device such as a smartphone, laptop, or other computing device. In such embodiments, any necessary power can be obtained from the user device in which the apparatus is implemented.

[0059] Figure 5 shows a high-level block diagram of a user device suitable for use in various embodiments. Specifically, Figure 5 shows an exemplary user device 500 (e.g., a mobile phone, smartphone, laptop, or other device (or part thereof) with audio processing capabilities). The user device 500 is shown as comprising one or more processors 532, memory 534, a mobile network interface 536, and an audio input / output interface 537. The processor 132 is coupled with and adapted to cooperate with the memory 134, the mobile network interface 536, the audio input / output interface 537, and various other support circuits (not shown) to provide various functions with respect to excitation signals / audio processing functions with respect to various embodiments as described herein.

[0060] The mobile network interface 536 is shown to facilitate communication with other devices via Wi-Fi, mobile networks, etc.

[0061] Audio input / output interface 537 is described as facilitating audio input and output to headphones via a 3.5mm plug, USB, uUSB, USB-C, Lightning, or other connectors.

[0062] In various embodiments, the audio input / output interface 537 provides wireless communication to headphones via Bluetooth® or other radio frequency (RF) communication methods.

[0063] In various embodiments, the audio input / output interface 537 can generate an output signal suitable for use as an input audio signal processed by the excitation signal detector 400 in Figure 4.

[0064] In various embodiments, the audio input / output interface 537 can receive the associated output audio signal generated by the excitation signal detector 400 in Figure 4 for processing the excitation voltage. In various embodiments, the audio input / output interface 537 can perform analog-to-digital conversion of the received audio signal to provide a digital representation of the received audio signal suitable for further processing by a user device 500 or a remote device (not shown) such as a remote server or audio processor.

[0065] Memory 134 stores programs, data, tools, etc., adapted for use in providing the various functions described herein with respect to the drawings. For example, memory 134 is shown as storing instructions related to mobile device functions and storage module 534-MDFS. This module is intended to perform various communications, displays, input / output, application execution, and all other functions typically associated with user devices such as mobile devices, smartphones, laptop computers, and desktop computers.

[0066] Memory 134 is also shown to store instructions related to the audio processing module 534-APM. This module is intended to perform various audio processing functions, digital signal processing (DSP) functions, and the like, as described herein with respect to various embodiments. These functions can be implemented using memory 534 and processor 532, and optionally using functions associated with the audio I / O interface 537. Thus, the various functions described herein can be implemented in hardware or in a combination of hardware and software.

[0067] Various functions that may be implemented in the embodiments include interpreting the received excitation signal(s) to identify within them one or more of the following: voice information (voice detection), gesture information (gesture detection), unique human identification information (user identification), heart rate and / or respiratory rate information (physiological monitoring), etc. Other functions are also intended by the inventors.

[0068] Figure 6 shows flowcharts of the method according to various embodiments. Method 600 in Figure 6 is suitable for implementation in whole or in part in audio receivers according to various embodiments, such as user devices (e.g., smartphones, laptops, or other devices). For example, in the case of an audio receiver that implements the zeroing circuit and (optionally) amplification circuit described above with respect to various figures, the entire Method 600 may be performed in the audio receiver when connected to standard "dumb" headphones, or when connected to headphones with more features, etc. In the case of an audio receiver that does not implement such a zeroing circuit, at least step 610 may be performed by an external device to the audio receiver, such as a device connected between the audio receiver and the headphones (e.g., device 400 described above with respect to Figure 4).

[0069] In step 610, the zeroing circuit is balanced. As discussed earlier, referring to box 615, the circuit for balancing can be avoided by using both left and right driver impedances in each arm of the zeroing circuit. The zeroing circuit may comprise a Wheatstone bridge, a potentiometer, or some other zeroing mechanism.

[0070] In step 620, any available audio input and excitation signals are received from the left and right speaker drivers, and the excitation signals are extracted therefrom. For example, in step 620, the voltages associated with the left and right speaker drivers can be received by a balanced zeroing circuit, so that the excitation signal Vo is used either directly (unamplified) by the audio processing device or in an amplified form, such as provided by the excitation signal detector 400 described above with respect to Figure 4.

[0071] In step 630, the excitation signal is processed as necessary for use by the audio processing module. For example, the excitation signal Vo provided by the zeroing device (or the amplified output signal provided by the excitation signal detector 400) can be coupled to the user device 500, and the audio I / O interface 537, the audio processing module 534-APM, or other modules can perform amplification, attenuation, analog-to-digital conversion, and / or other signal conditioning functions on the excitation signal Vo before performing specific interpretation / operation functions in response to the excitation signal Vo.

[0072] In step 640, the excitation signal (whether processed or not) is interpreted to identify the information provided therein, such as voice information (voice detection), gesture information (gesture detection), unique human identification information (user identification), and heart rate and / or respiratory rate information (user physiological information). For example, the audio I / O interface 537, the audio processing module 534-APM, or similar functions of the user device 500 or other audio processing modules / devices may perform various DSP processing functions, computing functions, data manipulation functions, etc., as described herein, in order to interpret the information provided by the excitation signal and act thereon. Such functions may be part of or related to other functions / applications performed by the user device 500 or other audio processing modules / devices, such as communication applications, health monitoring applications, and authentication applications.

[0073] In step 650, functions related to the interpreted excitation signal are performed. For example, the received audio information may be provided to an active communication application to support a call, or to a user interface as part of a speech recognition command, etc. The received gesture information can be used to update the context of the user interface or to invoke application control functions (for example, indicating that double-tapping the right speaker will skip 30 seconds forward in the audio presentation, or that double-tapping the left speaker will skip 30 seconds backward in the audio presentation). The received human identification information can be used to grant user authentication, such as accessing a specific program or even using a specific device (e.g., the headphones themselves, the user device, etc.). The received physiological information can be used to update a health monitoring program. Many other applications have been envisioned by the inventors. Repeat steps 620-650 to continuously receive any available excitation signals from the zeroing circuit.

[0074] Discussion of direct and indirect sensitivity

[0075] The first category of applications relies on measuring direct excitation signals received through the headphone diaphragm, such as human voices, touch-based gestures, and signals directly generated from physiological activity for sensing. Experiments have shown that even in the presence of an output audio signal, the received signal strength (RSS) measurement of the direct excitation signal is more than sufficient to support such applications.

[0076] The second category of applications relies on measuring the excitation signal received via a headphone diaphragm in response to a generated output signal (e.g., a chirp signal exhibiting frequency components spanning 20 Hz to 20 kHz over a short period of time, such as one second), such as human authentication which uses reflected signals associated with the generated signal to profile the structure of the inner ear of the person being authenticated. Experiments have shown that even in the presence of an output audio signal, the received signal strength (RSS) measurement of the indirect excitation signal is more than sufficient to support such applications.

[0077] Headphone on / off detection function and user authentication function

[0078] Various embodiments provide a non-intrusive authentication function that is optionally automatically triggered when the user puts on headphones. Such a function is implemented, exemplary, through the processing steps described herein, using the audio I / O interface 537, the audio processing module 534-APM, or a similar function on the user device 500 or other audio processing module / device.

[0079] Headphone on / off detection can be performed by processing the received excitation signal to determine whether the ambient acoustic noise indicates resonant noise within a cavity that amplifies ambient acoustic noise (i.e., the cavity where the user's ear canal and eardrum come together to form a resonant chamber). This amplified noise leads to a higher voltage signal output, and if it exceeds a threshold level, it can be interpreted as indicating that the user is wearing headphones.

[0080] Since plugged-in headphones typically operate in a quasi-full-duplex manner, they can be used to actively probe the response of ear channels. Specifically, in one embodiment, a user device (e.g., a smartphone) transmits an audio chirp signal (e.g., a short or burst signal exhibiting frequency components ranging from 20 Hz to 20 kHz for a short period of time, such as 1 second) through the headphones for propagation to the user's inner ear structure, while the two drivers of the headphones receive an echo signal that can be used to characterize the channel response of the ear canal.

[0081] Figures 7A-7B graphically show the channel responses measured for three different individuals responding to an audio chirp signal. It can be seen that the responses of the three channels differ dramatically in the frequency band above 3 kHz. This is because the physiological differences in the human ear are on a sub-centimeter scale and can be picked up by signals with sub-centimeter wavelengths (≧3 kHz). Individuals can be identified using their characteristic channel responses.

[0082] Because each ear is different (even the left and right ears of the same person), the channel response from the left ear does not cancel out the channel response from the right ear. Thus, the measured channel response can be used to characterize the user in a highly unique way. Note that channel responses may differ depending on the headphones used. Therefore, it is necessary to identify the user using standard headphones, or a scaling table can be used to normalize the user's channel response information across headphone brands and models.

[0083] Voice and noise detection function

[0084] Various embodiments provide voice / noise sensing functionality that can be invoked even while the user is listening to music with headphones. Such functionality is implemented, exemplary, through processing steps described herein, using the audio I / O interface 537, the audio processing module 534-APM, or similar functionality in the user device 500 or other audio processing module / device.

[0085] In voice-sensing operation mode, the user's voice is sensed and can be used for various purposes such as user authentication, application control, and speech-to-text processing. Furthermore, in the associated noise-sensing operation mode, ambient noise can be detected using excitation signals related to the ambient noise of the left and right speakers / diaphragms, and in response, such noise can be canceled via substantially identical phase-inverted signals of known similar power / volume levels. That is, by identifying the similarity of the left / right headphone periphery, various embodiments enable the detection and cancellation of common / ambient noise. Similarly, by identifying the difference in the left / right headphone periphery, various embodiments enable the detection of inadequate headphone sealing in the user's ears (i.e., if the headphones are properly fitted to each ear and provide a similar degree of noise isolation to each ear, the ambient noise to each ear should be substantially similar in power or volume level). That is, a difference in ambient noise levels between the left and right sides that exceeds a threshold amount can be considered to indicate inadequate sealing of the side related to the headphone driver, which represents a larger ambient noise level.

[0086] Physiological sensing function

[0087] Various embodiments provide physiological sensing functions that can be invoked even while the user is listening to music with headphones. Such functions are implemented, exemplary, through processing steps described herein, using the audio I / O interface 537, the audio processing module 534-APM, or similar functions of the user device 500 or other audio processing module / device.

[0088] Detecting a user's heart rate is difficult due to the extremely weak excitation signals caused by subtle vascular fluctuations in the ear canal. These signals may be below the noise floor and, being weak, can be easily interfered with by other movements of the headphone user.

[0089] To address these challenges, various embodiments utilize a low-pass filter with a very low cutoff frequency (e.g., 24 Hz) in the user device 500 to remove high-frequency noise introduced by echoes and environmental excitations in the audio input signal. Next, an autocorrelation function (ACF) is used to find periodicity indicating a heartbeat or respiration, as follows:

number

[0090] Here, x(n) is a copy of the signal output from the excitation signal detector 400, k is the lag, and N is the length of the received signal. Blindly enumerating all possible values ​​of k in the hope of finding a peak is computationally difficult and could introduce false positives. Therefore, the upper (U) and lower (L) limits of k are set based on possible human heart rates (approximately 35–200 bpm).

[0091] The goal can be represented by the following function.

number

[0092] Heart rate can be calculated as follows:

number

[0093] In various embodiments, non-repetitive physiological states such as seizures (e.g., Parkinson's microseizures), thermal tremors (teeth clenching), jaw clenching (jaw grinding / teeth grinding), and blood pressure can be detected. Furthermore, ear infections that alter the shape of the inner ear (e.g., due to pressure that deforms the eardrum) can be identified as deviations from a known profile of the user's external auditory canal / structure.

[0094] Touch-based gesture recognition

[0095] Various embodiments provide touch-based gesture recognition capabilities that can be invoked even while the user is listening to music with headphones. Such capabilities are implemented, exemplary, through processing steps described herein, using the audio I / O interface 537, the audio processing module 534-APM, or similar capabilities in the user device 500 or other audio processing module / device. It should be noted that these embodiments advantageously enable “dumb” headphones to operate as “smart” headphones, as discussed herein.

[0096] Specifically, the fluctuations in excitation output voltage caused by various gestures exhibit unique characteristics in both the spatial and temporal domains. Without loss of generality, four touch-based gestures are defined: i) tapping the left housing to indicate pause or play; ii) tapping the right housing to indicate mute; iii) sliding the left housing to indicate volume up; iv) sliding the right housing to indicate volume down. It should be noted that the supported gestures are not limited to these four. Various embodiments for analyzing / interpreting the temporal characteristics of excitations output a voltage signal for gesture recognition.

[0097] Figures 8A-8D show graphs of the channel response (RSS as a function of time) measured for various touch gestures.

[0098] Figure 8A shows an example where the user taps the left housing of the headphones, and Figure 8B shows an example where the user taps the right housing of the headphones. When the headphones are tapped, multiple peaks are observed, with the first large peak being the positive peak for the right tap (Figure 8A) and the negative peak for the left tap (Figure 8B). The RSS value here can be positive or negative depending on the direction of the signal. When the user taps the left housing of the headphones, the signal strength increases, and when the user taps the right housing, the signal strength decreases. This is because the Wheatstone bridge measures the differential voltage between the two drivers of the headphones. Therefore, the excitation signal measured by the bridge is phase-inverted with the right tap and left tap gestures. In other words, the excitation signals captured by the left and right drivers are phase-inverted when received by the zeroing circuit (bridge). Note that the music signal is orders of magnitude smaller and will not cause interference with the large peaks introduced by eavesdropping on the signal.

[0099] Figure 8C shows an example of a user sliding or swiping their finger across the left housing of the headphones, and Figure 8D shows an example of a user sliding or swiping their finger across the right housing of the headphones. Similar to left and right tap gestures, left and right slide gestures can be easily distinguished from the initial large peak, and the change in intensity shows an inverse trend. However, slide gestures typically last longer in the time domain than tap gestures. Therefore, signal duration is used to distinguish between tap and slide gestures.

[0100] In various embodiments, a cumulative sum (CUSUM) signal processing function is used to capture relevant temporal features for gesture recognition. Specifically, output voltage samples are X n Expressed as follows, the CUSUM function assigns weights ω to each signal sample. n Associate it with the value S in the following formula. n Calculate. S0=0 (Formula 4A) S n+1 =max(0,S n +x n -ω n ) (Formula 4B)

[0101] This simple function allows us to remove negative peaks while preserving large positive peaks. To remove positive peaks while preserving large negative peaks, replace the term max with the term min. Output voltage samples can be processed using two CUSUM functions (max and min) in parallel. Note that after applying the CUSUM function, the influence of ambient music signals is removed.

[0102] Next, this method determines whether to slide / tap left or right by applying the following rules.

number

[0103] Here, t1 and t2 are the start points of the first positive peak and the first negative peak, respectively.

[0104] This method defines the duration of a gesture as the average time between the first and last non-zero CUSUM values. To distinguish between tap and slide gestures, this method allows measuring their durations across different individuals and empirically setting a threshold, for example, 5000 samples (sampling rate 48kHz).

[0105] Accordingly, various embodiments provide systems, apparatus, methods, and mechanisms in which user information sensed by headphones can be provided to a user device or system, such as a smartphone or other device having audio processing capabilities.

[0106] In authentication interpretation mode, a user device or system can propagate an audio chirp signal to the headphones, thereby inducing an excitation signal that indicates the inner ear structure of the headphone wearer. Furthermore, ear infections or other conditions that alter the shape of the inner ear (e.g., due to pressure that deforms the eardrum) may be determined as deviations from a known profile of the user's ear canal / structure.

[0107] In gesture interpretation mode, a user device or system can monitor excitation signals and derive user gesture inputs suitable for use in adapting the functionality of the user device.

[0108] In voice interpretation mode, the user device or system can monitor excitation signals and derive user voice input suitable for use in adapting the user device's functions. Furthermore, by paying attention to left / right similarities (enabling detection and cancellation of common / ambient noise) and differences (power / volume differences of common / ambient noise, enabling detection of larger noise that may be due to poor headphone sealing in the user's ears), noise cancellation and headphone sealing detection can be determined for ambient noise received through both left and right headphones. In physiological interpretation mode, the user device or system can monitor excitation signals to derive repetitive physiological information of the headphone user (e.g., heart rate and / or respiration) suitable for use in adapting the function of the user device. In various embodiments, non-repetitive physiological states such as seizures (e.g., Parkinson's microseizures), thermal shivering (teeth grinding), jaw clenching (jaw gesture control / teeth grinding), and blood pressure can be detected. Furthermore, as described above, ear infections that alter the shape of the inner ear (e.g., due to pressure that deforms the eardrum) can be judged as deviations from a known profile of the user's external auditory canal / structure.

[0109] The embodiments described above primarily concern embodiments that operate by converting the left and / or right audio output signals to non-stereo (i.e., mono) audio signals and then sensing or extracting excitation signals from them. This mono audio conversion may affect the user experience in some applications, but not all. Voice call applications are typically not stereo applications, so there is no significant impact on the user experience from various embodiments. Music playback applications are typically stereo applications, so the user experience may be impaired by various embodiments. User identification applications are short-duration applications, so the impairment of the user experience is limited to occasional, short periods. Physiological sensing applications, such as heart rate monitoring, typically require continuous sensing, so the user experience may be impaired (various embodiments provide a switch to allow the user to turn off the device).

[0110] The above embodiment can be used for stereo processing by balancing the left and right drivers independently, rather than using separate matching networks to balance them as a single pair. In this way, the user can maintain a stereo experience.

[0111] Here, with respect to Figure 5, we will describe additional embodiments of stereo audio applications, such as music playback applications, that are invoked on user devices (e.g., mobile phones, computers, or other audio sources / players) as described above.

[0112] The user device 500 in Figure 5 above can be configured to generate left and right speaker driver signals from a stereo audio source (e.g., stored or streaming audio files, stored or streaming media files, and / or other types of content containing audio information), which are then provided to the user's headphones via a wired or wireless connection.

[0113] The headphones described above include left and right headphone speaker drivers that are operable to drive corresponding left and right speaker diaphragms, generating corresponding sound pressures, thereby enabling the user of the headphones to hear music or other audio signals. The speaker drivers are also used as general-purpose sensors to receive excitation signals from the left and right speaker diaphragms, indicating the direct or indirect pressure applied to the speaker diaphragms by the user's ear canal, which acoustically cooperates with the speaker diaphragms operably coupled to the drivers.

[0114] The user headphones described above also include circuitry configured to support various functions described herein in relation to embodiments.

[0115] Figure 9 shows a schematic diagram of an apparatus according to one embodiment. Specifically, Figure 9 shows an excitation signal detector 900 coupled to receive an audio signal from a stereo audio source (e.g., the stereo audio output signal of the user device 500 in Figure 5 via a 3.5mm plug, Universal Serial Bus (USB), uUSB, USB-C, Lightning, or other connector, etc.), and uses the received audio signal to drive the left and right headphone speakers respectively, presenting the audio signal to the user through the left and right headphone speakers, while simultaneously acquiring excitation energy from each of the left and right headphone speakers. The acquired excitation energy is obtained via a differential or differential amplifier circuit and provided as an output signal Out suitable for further processing as described herein.

[0116] Referring to Figure 9, the left (V) is received from the user device 500. in left) and right (V in The audio input signals are coupled to the first terminals of the respective left and right speaker drivers (the second terminals of the speaker drivers are coupled to ground) via matching resistors R1 and R2, and then to the respective input terminals of the differential amplifier (e.g., the + / - terminals of the differential / operational amplifier circuit). Assuming standard 50-ohm audio impedance matching, resistors R1 and R2 would each be 50-ohm resistors, but other values ​​can be used as long as R1 is substantially equal to R2. More generally, resistors R1 and R2 are chosen to ensure that each of the left and right channel paths is associated with substantially similar impedances (i.e., RLC impedances).

[0117] differential amplifier output signal V out This is equal to α(Lin-Rin)+(Lout-Rout), where α is the scaling factor. Input signal V in left(t) and V in right(t) is known because it is the analog output signal corresponding to the digital audio signal of the audio / media source processed by the user device.

[0118] Amplifier output signal V out Also, the reflected signal V, which is received from the left and right driver circuits and contains the excitation energy obtained from the respective left and right headphone speakers, is also received. out left(t) and V out Includes right(t).

[0119] If the output reflection signal of Lout-Rout is very small and negligible, the scaling factor α is the difference between the input signals (i.e., V). in left(t)-V in This can be determined by the cross-correlation between right(t) and the output signal Vout(t).

[0120] That is, α(V in left(t)-V in right(t)) is the output reflected signal (V) when stereo audio / music is being played. out left(t)-V out It can be subtracted from right(t).

[0121] This processing step can be performed using the various processing capabilities of the user device 500.

[0122] Figure 10 shows a flowchart of a method according to one embodiment. Specifically, Figure 10 shows the output signal V of the amplifier of the apparatus in Figure 9. out A flowchart of method 1000 is shown, which processes the data and extracts the excitation energy obtained from each of the left and right headphone speakers, as will be discussed herein in relation to various embodiments.

[0123] In step 1010, the user device 500 transmits a stereo audio signal to the device 900 in Figure 9, such as a pair of user headphones, which include such a device. That is, in step 1010, the audio input signal V in left(t) and V in right(t) is supplied to the apparatus 900 in Figure 9.

[0124] In step 1020, the output signal V from the device 900 in Figure 9 out This is received by the user device 500. That is, the user device 500 receives the reflected signal V from the left and right driver circuits, which includes the excitation energy obtained from the respective left and right headphone speakers. out left(t) and V out Signal V containing right(t) out Receive.

[0125] In step 1030, the received signal V outThe various components of the audio signal are aligned with the representation of the initially transmitted audio signal, enabling the various comparison and processing steps described herein. The alignment may include analog or digital processing, such as providing time alignment, phase alignment, gain alignment, etc., to provide one or both of the analog and digital representations of the various signals, enabling further processing by the user device 500, for example, through the audio processing functions described above.

[0126] In step 1040, the aligned signal is processed, thereby receiving the received signal V out Excitation signals are extracted from the system, and the results are interpreted to identify the information provided therein, such as voice information (voice detection), gesture information (gesture detection), unique human identification information (user identification), and heart rate and / or respiratory rate information (user physiological information). Advantageously, the user can listen to the provided audio / music through headphones.

[0127] The audio I / O interface 537, the audio processing module 534-APM, or similar functions of the user device 500 or other audio processing modules / devices can perform various DSP processing functions, computing functions, data manipulation functions, etc., as described herein, in order to interpret information provided by excitation signals and act accordingly. Such functions may be part of or related to other functions / applications performed by the user device 500 or other audio processing modules / devices, such as communication applications, health monitoring applications, authentication applications, etc.

[0128] In step 1050, functions related to the interpreted excitation signal are performed, as described above with respect to step 650 in Figure 6.

[0129] By continuously repeating steps 1010 to 1050, any available excitation signal can be continuously received from the differential circuit of the device.

[0130] Figure 11 shows a schematic diagram of an apparatus according to one embodiment. Specifically, Figure 11 shows an excitation signal detector 1100 coupled to receive an audio signal from a stereo audio source (e.g., the stereo audio output signal of the user device 500 in Figure 5 via a 3.5mm plug, Universal Serial Bus (USB), uUSB, USB-C, Lightning, or other connector, etc.), and uses the received audio signal to drive the left and right headphone speakers respectively, presenting the audio signal to the user through the left and right headphone speakers, while simultaneously acquiring excitation energy from each of the left and right headphone speakers, the acquired excitation energy being obtained via a differential or differential amplifier circuit and provided as an output signal Out suitable for further processing as described herein.

[0131] Referring to Figure 11, the left (V) is received from the user device 500. in left) and right (V in The audio input signal is coupled not only to the respective input terminals of the left and right unity-gain buffers B1 and B2, but also to the respective input terminals of the first differential amplifier A1 (e.g., the + / - terminals of the differential / operational amplifier circuit).

[0132] The output signal of the first differential amplifier A1 is equal to the difference between the left and right input signals.

[0133] A1 out =V in left(t)-V in right(t).

[0134] The output terminals of the left and right buffers B1 and B2 are coupled to the first terminals of the respective left and right speaker drivers (the second terminals of the speaker drivers are coupled to ground), as well as to the respective input terminals of the second differential amplifier A2.

[0135] The output signal of the second differential amplifier A2 is equal to the difference between the buffered left and right input signals, including the reflected signals Rleft and Rright.

[0136] A2 out =B(V in left(t))-B(V in right(t))+Rleft(t)-Rright(t).

[0137] The output terminals of the first differential amplifier A1 and the second differential amplifier A2 are connected to the respective input terminals of the third differential amplifier A3.

[0138] The output signal V out of the third differential amplifier is equal to the difference between the output signals of the second and first differential amplifiers, which is approximately equal to the reflected signal from the speaker diaphragm (i.e., the left and right excitation signals).

[0139] A3 out =A2 out -A1 out

[0140] A3 out =(B(V in left(t))-B(V in right(t))+Rleft(t)-Rright(t))-V in left(t)-V in right(t)

[0141] A3 out =Rleft(t)-Rright(t)

[0142] Thus, within the context of the apparatus 1100 of FIG. 11, the output signal V outThis can be processed by the user device 500 as an analog representation of the excitation signal derived from the user.

[0143] Figure 12 shows a schematic diagram of a device suitable for use in various embodiments. Specifically, Figure 12 shows a headphone circuit, i.e., a 3-port audio frequency circulator, suitable for use in place of the various signal conditioning / processing circuits described above in relation to various embodiments.

[0144] The first port of the circulator receives left (V) from user device 500. in left) or right (V in (right) It is configured to receive audio signals from an audio source, such as an audio input signal. The input audio signal received at the first port is output through the second port, which is connected to a speaker driver circuit. The speaker driver circuit also provides excitation energy / signal from the speaker as an input signal to the second port. The excitation energy / signal received at the second port is output as an output signal Vout through the third port, which is connected to an audio input such as a microphone on the user device 500.

[0145] The apparatus shown in Figure 12 can be used to replace other circuits described herein in order to avoid or minimize the use of the Wheatstone bridge, zeroing circuit, differential amplifier, etc.

[0146] In this way, the device according to various embodiments may include stereo headphones configured to provide a sensing platform, using one or more headphone drivers to derive excitation energy from speaker diaphragms that electrically cooperate. Various embodiments can be used to interpret the received excitation signal(s) to identify therein voice information (voice detection), gesture information (gesture detection), unique human identification information (user identification), heart rate and / or respiratory rate information (physiological information), etc. In this way, new applications are provided within contexts such as mobile health, user interface, context awareness, and identification / authentication.

[0147] Various embodiments are specified in the claims. At least a subset of these various embodiments, and other embodiments, are specified in the following numbered clauses.

[0148] Article 1 A device for receiving information from a headset, wherein the headset comprises a magnetic coil driver operably coupled to a diaphragm, the magnetic coil driver configured to receive an audio input signal and, in response thereto, generate air vibrations in the diaphragm corresponding to the audio input signal, the device further comprising: a zeroing circuit configured to selectively couple to the magnetic coil driver to zero out the electrical energy associated with the audio input signal, thereby providing an output signal mainly comprising the electrical energy associated with an excitation signal generated by the magnetic coil driver in response to an external pressure applied to the diaphragm; and an amplifier circuit configured to amplify the output signal of the zeroing circuit, thereby providing an excitation signal that enables determination of the external pressure applied to the diaphragm.

[0149] Article 2 The apparatus according to Clause 1, wherein the zeroing circuit comprises a Wheatstone bridge including two balanced voltage divider arms, and one of the voltage divider arms includes at least one magnetic coil operably coupled to the diaphragm.

[0150] Article 3 The apparatus according to Clause 1, wherein the headset further comprises a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver being configured to receive the audio input signal and, in response thereto, generate air vibrations in the second diaphragm corresponding to the audio input signal, the first and second magnetic coil drivers exhibit substantially similar impedances, and the zeroing circuit comprises a Wheatstone bridge including two balanced voltage divider arms, each voltage divider arm including one of the magnetic coil drivers.

[0151] Article 4 The apparatus according to Clause 1, wherein the headset is configured to connect to an audio output device, and the apparatus is configured to connect to both the headset and the audio output device.

[0152] Article 5 The apparatus according to Clause 1, wherein the headset is configured to connect to a user device, and the apparatus is configured to connect to both the headset and the user device.

[0153] Article 6 The apparatus according to Clause 2, wherein the excitation signal includes an audio signal caused by external pressure applied to the diaphragm from the voice of the wearer of the headphones.

[0154] Article 7 The apparatus according to Clause 1, wherein the excitation signal includes an audio signal caused by an external pressure applied to the diaphragm, ranging from a reference (nominal) pressure related to the shape of the ear canal of the wearer of the headphones.

[0155] Article 8 The apparatus according to Clause 1, wherein the excitation signal includes an audio signal caused by an external pressure applied to the diaphragm from repetitive pressure changes associated with the beating heart of the wearer of the headphones.

[0156] Article 9 The apparatus according to Clause 1, further comprising a housing configured to mechanically support the zeroing circuit and the amplifier circuit, wherein the housing has a first headphone connector configured to provide electromechanical coordination between the apparatus and a headphone device, and a second headphone connector configured to provide electromechanical coordination between the apparatus and a user device.

[0157] Clause 10 The apparatus according to Clause 9, wherein the first and second headphone connectors include at least one of a 3.5mm plug, a Universal Serial Bus (USB) connector, a Micro USB connector, a USB-C connector, and a Lightning connector.

[0158] Article 11 The device described in Clause 1, wherein the aforementioned device is included within a user device.

[0159] Article 12 The apparatus according to Clause 5, wherein the user device propagates an audio chirp signal to the headphones in an authentication interpretation operation mode, thereby inducing an excitation signal indicating the inner ear structure of the headphone wearer.

[0160] Article 13 The apparatus according to Clause 5, wherein the user device monitors excitation signals in a gesture interpretation operating mode and derives a user gesture input suitable for use in adapting the functions of the user device therefrom.

[0161] Article 14 The apparatus according to Clause 5, wherein the user device monitors excitation signals in a voice interpretation operating mode and derives a user voice input suitable for use in adapting the functions of the user device therefrom.

[0162] Article 15 The apparatus according to Clause 1, further comprising: a headset further comprising a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver configured to receive a second audio input signal and, in response thereto, generate air vibrations in the second diaphragm corresponding to the second audio input signal; the apparatus further comprising: a second zeroing circuit configured to selectively couple to the second magnetic coil driver to zero out the electrical energy associated with the second audio input signal, thereby providing a second output signal mainly comprising the electrical energy associated with an excitation signal generated by the second magnetic coil driver in response to an external pressure applied to the second diaphragm; and a second amplifier circuit configured to amplify the output signal of the second zeroing circuit, thereby providing a second excitation signal configured to enable determination of the external pressure applied to the second diaphragm.

[0163] Article 16 The apparatus according to Clause 1, wherein the headset further comprises a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver configured to receive a second audio input signal and in response generate an air vibration in the second diaphragm corresponding to the second audio input signal, the zeroing circuit comprises a first differential amplifier configured to amplify the difference between the first and second audio input signals, and a second differential amplifier configured to amplify the difference between the excitation signals generated by the first and second magnetic coil drivers, and the amplifier circuit comprises a third differential amplifier configured to amplify the difference between the output signals of the first and second differential amplifiers.

[0164] Article 17 The apparatus according to Clause 16, further comprising a first buffer configured to provide a buffered first audio signal to the first magnetic coil driver, and a second buffer configured to provide a buffered second audio signal to the second magnetic coil driver.

[0165] Article 18 The apparatus according to Clause 16, wherein the zeroing circuit and the amplification circuit each comprise a three-port circulator having a first port configured to receive an audio input signal, a second port configured to provide the audio signal to the magnetic coil driver and receive electrical energy associated with an excitation signal from the magnetic coil driver, and a third port configured to provide the excitation signal, which is configured to enable the determination of the external pressure applied to the diaphragm.

[0166] Article 19 A method for receiving information from a headset, wherein the headset comprises a magnetic coil driver operably coupled to a diaphragm, the magnetic coil driver is configured to receive an audio input signal and, in response, generate air vibrations in the diaphragm corresponding to the audio input signal, and the method is A method comprising: zeroing the electrical energy associated with the audio input signal, thereby providing an output signal that mainly comprises the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to an external pressure applied to the diaphragm; and amplifying the zeroing circuit output signal, thereby providing an excitation signal configured to enable the determination of the external pressure applied to the diaphragm.

[0167] Article 20 The method according to Clause 19, further comprising, in an authentication interpretation operation mode, propagating an audio chirp signal to the headphones and interpreting the received excitation signal to determine the profile of the inner ear structure of the headphone wearer.

[0168] Article 21 The method according to Clause 19, further comprising monitoring the received excitation signal in the gesture interpretation operating mode and deriving a user gesture input suitable for use in adapting the functionality of the user device therefrom.

[0169] Article 22 The method according to Clause 19, further comprising monitoring the received excitation signal in a voice interpretation operating mode and deriving a user voice input suitable for use in adapting the functions of the user device therefrom.

[0170] Article 23 The method according to Clause 19, further comprising monitoring the received excitation signal in a physiological interpretation operating mode and deriving therefrom iterative physiological information of the headphone user that is suitable for use in adapting the functions of the user device.

[0171] Article 24 The method according to Clause 23, wherein the repetitive physiological information includes physiological information relating to either or both heart rate and respiratory information.

[0172] Article 25 The method according to Clause 19, further comprising monitoring the received excitation signal in a physiological interpretation operating mode and deriving therefrom physiological information of the headphone user that is suitable for use in adapting the function of the user device, wherein the physiological information relates to one or more of the following: microseizures, thermal shivering, jaw clenching, and blood pressure.

[0173] Article 26 The method according to Clause 19, further comprising monitoring the received excitation signal in the noise interpretation operating mode and deriving from it an ambient noise audio input suitable for use in generating a corresponding noise-canceling signal.

[0174] Article 27 The method according to Clause 19, further comprising, in a noise interpretation operating mode, monitoring excitation signals received from each of the left and right headphone drivers and deriving their respective ambient noise input signals, and determining that the difference between the respective ambient noises exceeding a threshold amount indicates that the headphone sealing associated with the headphone driver representing a larger ambient noise level is inadequate.

[0175] Article 28 A device for receiving information from a headset, wherein the headset comprises first and second speaker diaphragms coupled to first and second magnetic coil drivers, respectively, the device comprising: a first differential amplifier configured to amplify the difference between first and second received audio input signals; a second differential amplifier configured to amplify the difference between excitation signals generated by the first and second magnetic coil drivers; and a third differential amplifier configured to amplify the difference between the output signals of the first and second differential amplifiers, thereby providing an output signal comprising primarily electrical energy related to the excitation signals generated by the magnetic coil drivers in response to external pressure applied to the speaker diaphragms, and configured for processing by a computing device.

[0176] Article 29 The apparatus according to Clause 28, further comprising: a first buffer configured to provide a buffered first audio signal to the first magnetic coil driver; and a second buffer configured to provide a buffered second audio signal to the second magnetic coil driver.

[0177] Article 30 A device for receiving information from a headset, wherein the headset comprises first and second speaker diaphragms coupled to first and second magnetic coil drivers, respectively; the device comprises first and second matching resistors for coupling first and second audio input signals to the first and second magnetic coil speaker diaphragm drivers, respectively, and to the first and second input terminals of an amplifier, respectively; the amplifier is configured to produce an output signal indicating the difference between the first and second audio input signals and the difference between the electrical energies associated with excitation signals generated by the first and second magnetic coil speaker diaphragm drivers in response to an external pressure applied to the respective first and second magnetic coil speaker diaphragm drivers; the output signal is configured to be processed by a computing device to zero out the signals associated with the first and second audio input signals and extract the signals associated with the magnetic coil speaker diaphragm drivers.

[0178] Various embodiments can be implemented as plug-in peripherals that connect headphones to a pairing device (e.g., a user device such as a smartphone or computer), or as integrated circuits built into headphones or a pairing device.

[0179] Although various embodiments incorporating the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other various embodiments that still incorporate these teachings. Thus, while the foregoing covers various embodiments of the present invention, other and further embodiments of the present invention can be devised without departing from the basic scope of the present invention.

Claims

1. A device for receiving information from a headset, wherein the headset comprises a magnetic coil driver operably coupled to a diaphragm, the magnetic coil driver is configured to receive an audio input signal and, in response, generate air vibrations in the diaphragm corresponding to the audio input signal, and the device is A zeroing circuit is configured to be selectively coupled to the magnetic coil driver in order to reduce the electrical energy associated with the audio input signal to zero, thereby providing an output signal that mainly consists of the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to an external pressure applied to the diaphragm. An apparatus comprising: an amplifier circuit for amplifying the output signal of the zeroing circuit to provide an excitation signal configured to enable the determination of the external pressure applied to the diaphragm.

2. The apparatus according to claim 1, wherein the zeroing circuit comprises a Wheatstone bridge including two balanced voltage divider arms, and one of the voltage divider arms includes at least one magnetic coil operably coupled to the diaphragm.

3. The headset further comprises a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver being configured to receive the audio input signal and, in response, generate air vibrations in the second diaphragm corresponding to the audio input signal, and the first and second magnetic coil drivers exhibit substantially similar impedances. The apparatus according to claim 1, wherein the zeroing circuit comprises a Wheatstone bridge including two balanced voltage divider arms, each voltage divider arm including one of the magnetic coil drivers.

4. The apparatus according to claim 1, wherein the headset is configured to connect to an audio output device, and the apparatus is configured to connect to both the headset and the audio output device.

5. The apparatus according to claim 1, wherein the headset is configured to connect to a user device, and the apparatus is configured to connect to both the headset and the user device.

6. The apparatus according to claim 2, wherein the excitation signal includes an audio signal caused by external pressure applied to the diaphragm from the voice of the wearer of the headphones.

7. The apparatus according to claim 1, wherein the excitation signal includes an audio signal caused by an external pressure applied to the diaphragm from a reference pressure related to the shape of the ear canal of the wearer of the headphones.

8. The apparatus according to claim 1, wherein the excitation signal includes an audio signal triggered by an external pressure applied to the diaphragm from repetitive pressure changes associated with the beating heart of the wearer of the headphones.

9. The apparatus according to claim 1, further comprising a housing configured to mechanically support the zeroing circuit and the amplifier circuit, wherein the housing has a first headphone connector configured to provide electromechanical coordination between the apparatus and a headphone device, and a second headphone connector configured to provide electromechanical coordination between the apparatus and a user device.

10. The apparatus according to claim 9, wherein the first and second headphone connectors include at least one of a 3.5 mm plug, a Universal Serial Bus (USB) connector, a Micro USB connector, a USB-C connector, and a Lightning connector.

11. The apparatus according to claim 1, wherein the apparatus is included within a user device.

12. The apparatus according to claim 5, wherein the user device propagates an audio chirp signal to the headphones in the authentication interpretation operation mode, thereby inducing an excitation signal that indicates the inner ear structure of the headphone wearer.

13. The apparatus according to claim 5, wherein the user device monitors excitation signals in gesture interpretation mode and derives a user gesture input suitable for use in adapting the functions of the user device therefrom.

14. The apparatus according to claim 5, wherein the user device monitors excitation signals in a voice interpretation operation mode and derives a user voice input suitable for use in adapting the functions of the user device therefrom.

15. The headset further comprises a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver configured to receive a second audio input signal and, in response, generate air vibrations in the second diaphragm corresponding to the second audio input signal, and the device further comprises A second zeroing circuit, configured to be selectively coupled to the second magnetic coil driver in order to zero out the electrical energy associated with the second audio input signal, thereby providing a second output signal that mainly consists of the electrical energy associated with the excitation signal generated by the second magnetic coil driver in response to an external pressure applied to the second diaphragm, The apparatus according to claim 1, further comprising: a second amplifier circuit for amplifying the output signal of the second zeroing circuit, thereby providing a second excitation signal configured to enable the determination of the external pressure applied to the second diaphragm.

16. The headset further comprises a second magnetic coil driver operably coupled to a second diaphragm, the second magnetic coil driver being configured to receive a second audio input signal and, in response, generate air vibrations in the second diaphragm corresponding to the second audio input signal. The zeroing circuit comprises a first differential amplifier configured to amplify the difference between the first and second audio input signals, and a second differential amplifier configured to amplify the difference between the excitation signals generated by the first and second magnetic coil drivers. The apparatus according to claim 1, wherein the amplifier circuit comprises a third differential amplifier configured to amplify the difference between the output signals of the first and second differential amplifiers.

17. A first buffer configured to provide a buffered first audio signal to the first magnetic coil driver, The apparatus according to claim 16, further comprising: a second buffer configured to provide a buffered second audio signal to the second magnetic coil driver.

18. The apparatus according to claim 16, wherein the zeroing circuit and the amplification circuit each comprise a three-port circulator having a first port configured to receive an audio input signal, a second port configured to provide the audio signal to the magnetic coil driver and to receive electrical energy associated with an excitation signal from the magnetic coil driver, and a third port configured to provide the excitation signal, which enables the determination of the external pressure applied to the diaphragm.

19. A method for receiving information from a headset, wherein the headset comprises a magnetic coil driver operably coupled to a diaphragm, the magnetic coil driver is configured to receive an audio input signal and, in response, generate air vibrations in the diaphragm corresponding to the audio input signal, and the method is The electrical energy associated with the audio input signal is reduced to zero, thereby providing an output signal that mainly consists of the electrical energy associated with the excitation signal generated by the magnetic coil driver in response to the external pressure applied to the diaphragm. A method comprising amplifying the output signal of the zeroing circuit to provide an excitation signal configured to enable the determination of the external pressure applied to the diaphragm.

20. In the authentication interpretation operation mode, the audio chirp signal is propagated to the headphones, The method according to claim 19, further comprising interpreting the received excitation signal to determine the profile of the inner ear structure of the headphone wearer.

21. The method according to claim 19, further comprising monitoring the received excitation signal in the gesture interpretation operation mode and deriving a user gesture input suitable for use in adapting the functionality of the user device therefrom.

22. The method according to claim 19, further comprising monitoring the received excitation signal in the voice interpretation operation mode and deriving a user voice input suitable for use in adapting the functions of the user device therefrom.

23. The method according to claim 19, further comprising monitoring the received excitation signal in a physiological interpretation operating mode and deriving therefrom iterative physiological information of the headphone user that is suitable for use in adapting the functions of the user device.

24. The method according to claim 23, wherein the repetitive physiological information includes physiological information relating to either or both heart rate and respiratory information.

25. The method according to claim 19, further comprising monitoring the received excitation signal in a physiological interpretation operating mode and deriving therefrom physiological information of the headphone user that is suitable for use in adapting the function of the user device, wherein the physiological information relates to one or more of the following: microseizures, thermal shivering, jaw clenching, and blood pressure.

26. The method according to claim 19, further comprising monitoring the received excitation signal in a noise interpretation operating mode and deriving from it an ambient noise audio input suitable for use in generating a corresponding noise-canceling signal.

27. The method according to claim 19, further comprising: monitoring excitation signals received from each of the left and right headphone drivers in a noise interpretation operation mode and deriving each ambient noise input signal therefrom; and determining that the difference between the respective ambient noises exceeding a threshold amount indicates that the headphone sealing associated with the headphone driver representing a larger ambient noise level is inadequate.

28. A device for receiving information from a headset, wherein the headset comprises first and second speaker diaphragms coupled to first and second magnetic coil drivers, respectively, and the device is A first differential amplifier configured to amplify the difference between first and second received audio input signals, A second differential amplifier configured to amplify the difference between the excitation signals generated by the first and second magnetic coil drivers, An apparatus comprising: a third differential amplifier configured to amplify the difference between the output signals of the first and second differential amplifiers, thereby providing an output signal mainly comprising electrical energy related to the excitation signal generated by the magnetic coil driver in response to an external pressure applied to the speaker diaphragm, and configured for processing by a computing device.

29. A first buffer configured to provide a buffered first audio signal to the first magnetic coil driver, The apparatus according to claim 28, further comprising: a second buffer configured to provide a buffered second audio signal to the second magnetic coil driver.

30. A device for receiving information from a headset, wherein the headset comprises first and second speaker diaphragms coupled to first and second magnetic coil drivers, respectively, and the device is The system includes first and second matching resistors for coupling the first and second audio input signals to the respective first and second magnetic coil speaker diaphragm drivers, and to the respective first and second input terminals of the amplifier. The amplifier is configured to generate an output signal that represents the difference between the first and second audio input signals and the difference in electrical energy associated with the excitation signals generated by the first and second magnetic coil speaker diaphragm drivers in response to the external pressure applied to each of the first and second magnetic coil speaker diaphragm drivers. The device is configured to process the output signal so that a computing device can zero out the signals associated with the first and second audio input signals and extract the signals associated with the magnetic coil speaker diaphragm driver.

Images