COMMUNICATION EQUIPMENT THAT ALLOWS FULL DUPLEX WITH IN-EAR SOUND RECORDING, AND A COMMUNICATION SYSTEM TO THAT SUITABLE

Description

[0001] The present invention relates to the technical field of communications with sound pickup in the user's ear, and more particularly to communication equipment enabling full duplex with sound pickup in the ear and to a communication system comprising it.

[0002] Currently, the vast majority of communication devices that pick up the user's voice in the ear use a PTT (Push-To-Talk) button. This button stops the sound emitted by the speaker located in the ear, next to the microphone used for sound pickup. These devices enable half-duplex communication. Without the PTT button, the microphone in the user's ear canal simultaneously and inseparably records the user's voice, the voice(s) of the other person(s) speaking, and possibly a recording of the user's surrounding sound. Indeed, many of these devices also implement a playback of the surrounding sound to the user, a system known as pass-through or talk-through.This audio playback is necessary to avoid isolating the user from their surroundings, especially when the device includes in-ear hearing protection. It's understandable that half-duplex communication relying on a PTT button can be cumbersome, particularly during conversations. An alternative to the PTT button is the use of a speech detector, which, if it detects the user speaking, automatically stops the transmission of the voice signal and the playback of the ambient sound, and records the user's voice. However, this system also has drawbacks, notably the possibility of unintentionally stopping the transmission of the voice signal and the playback of the ambient sound when the user speaks directly to someone next to them, without using a radio system.Furthermore, for communication equipment with in-ear sound pickup, conventional echo cancellation algorithms cannot be applied because the microphone is very close to the speaker. Therefore, establishing full-duplex communication is difficult.

[0003] In the prior art, European patent application EP3188507 A1 describes a portable hearing device that enables near-full-duplex communication with ambient sound reproduction. In this document, the sound of the source voice signal and the ambient sound reproduction, captured by the ear-receiving microphone, are attenuated in the return voice signal using an electronic compensation filter circuit. This circuit employs an estimated transfer function that models the acoustic transfer function in the user's ear between the device's speaker and microphone. However, this solution has some drawbacks: the compensation device is complex, the transfer function can be difficult to model, and its effectiveness remains limited, particularly at low frequencies.This solution is also unsuitable for use with hearing protection. This document, EP3188507 A1, specifically concerns hearing aids. It is not applicable to hearing protectors, which are designed to provide maximum protection from the outside environment, which is the primary objective for hearing protectors. In this document, EP3188507 A1, the stability of the internal speaker / microphone transfer function is critical, especially at low frequencies. Furthermore, this document is unable to handle a significant computational load.

[0004] US 2009 / 147966 A1 and US 2022 / 014849 A1 describe communication equipment according to the prior art.

[0005] Therefore, prior art solutions proposed for in-ear sound-capture communication equipment still have drawbacks and improvements are possible.

[0006] The invention aims, in particular, to provide communication equipment, at least partially in-ear, configured to allow full-duplex communication with sound pickup in the ear. Another objective of the invention is to provide communication equipment configured to generate a return voice signal.

[0007] Another objective of the invention is to provide communication equipment configured to provide a simple and effective anti-echo function to avoid sending back the other person's own voice and prevent feedback.

[0008] Another objective of the invention is to provide communication equipment configured to provide an anti-echo function by emitting the voice signal in opposite phase to the user's right and left ears.

[0009] Another objective of the invention is to provide communication equipment configured to allow the user to hear the surrounding sound environment. Another objective of the invention is to provide communication equipment configured to minimize the amount of surrounding sound transmitted to the other party or parties.

[0010] Another objective of the invention is to provide communication equipment configured to reproduce the ambient sound environment to the user in a muted manner. Another objective of the invention is to provide communication equipment configured to allow a user to simultaneously speak and listen to a voice signal and, optionally, a reproduction of the ambient sound environment without pressing a button.

[0011] Another objective of the invention is to provide communication equipment including in-ear hearing protection.

[0012] Another objective of the invention is to provide a communication system enabling full duplex communication with sound capture in the ear using communication devices and communication equipment according to the invention.

[0013] Thus, the present invention relates to a communication equipment allowing full duplex with sound pickup in the ear, the communication equipment being configured to receive at least one source voice signal transmitted by at least one communication device and to provide a total output signal, the communication equipment comprising: a first device designed to be inserted into one of a user's right and left ear, and a second device designed to be inserted into the other of the user's right and left ear; each of the first device and the second device comprising a first microphone and a loudspeaker configured to be arranged, in use, opposite an ear canal of the user;characterized by the fact that: the communication equipment is configured such that a first voice signal is delivered to the loudspeaker of the first device and a second voice signal is delivered to the loudspeaker of the second device, the first and second voice signals being based on at least one source voice signal such that the first voice signal and the second voice signal are in opposite phase, i.e. out of phase by Pi; the first microphone of the first, respectively of the second, device is configured to capture, in the respective ear, at least one voice of the user and a sound from the first, respectively of the second, voice signal generated by the loudspeaker of the first, respectively of the second, device, and to deliver at output a sound pickup signal from the first, respectively of the second, device;the communication equipment is configured to generate a pre-output signal corresponding to the first device, and a pre-output signal corresponding to the second device, respectively from the sound pickup signal of the first and second devices and to generate an output signal corresponding to the first device and an output signal corresponding to the second device, comprising respectively, at least one component related to the pre-output signal corresponding to the first device and one component related to the pre-output signal corresponding to the second device;and the communication equipment further includes a first summing unit configured to receive as input and to sum the output signal of the first device and the output signal of the second device, the first summing unit delivering as output the total output signal equal to the sum of the output signal of the first device and the output signal of the second device, and the total output signal comprising a user voice component and being free of components of the first and second voice signals.

[0014] A communication device with in-ear sound pickup, as described above, allows the source voice signal to be continuously transmitted to the user's ears, resulting in a total output signal consisting solely of the user's voice. This enables full-duplex communication. The source voice signal, typically the speaker's voice, is transmitted out of phase (Pi) to the right and left ears, such that the summation of the sound pickups in the right and left ears eliminates the sound associated with the source voice signal.

[0015] The communication equipment according to this embodiment is therefore configured to implement a simple and very effective anti-echo function.

[0016] The communication equipment may receive source voice signals from several communication devices; in this case, the communication equipment is configured to combine the different source voice signals received.

[0017] Communication devices can, for example, be a radio, a walkie-talkie, a telephone, a smartphone, a digital tablet, or a computer.

[0018] According to one embodiment, the communication equipment further comprises a total output signal processing module configured to process the total output signal in order to generate, from the total output signal, at least one of a return voice signal and two return voice signals in opposite phase, the processing being at least one of a reduction of the occlusion effect, a reduction of the bone conduction effect, and amplification, in order to make the total output signal more natural for the interlocutor.

[0019] In the case of in-ear recording, due to the occlusion effect and bone conduction, the user's voice—that is, the speech signal—is strongly amplified in the low-frequency range, particularly below 500 Hz. Processing the total output signal can therefore, for example, involve processing to make the user's voice sound more natural to the listener, thereby improving speech quality and intelligibility.

[0020] In one embodiment, the communication equipment is configured to receive two out-of-phase source voice signals from each communication device, to use one of the two source voice signals to generate the first voice signal and deliver it to the loudspeaker of the first device, and to use the other source voice signal to generate the second voice signal and deliver it to the loudspeaker of the second device. In another embodiment, the communication equipment includes a source voice signal processing module configured to receive a single source voice signal from each communication device and to generate the first and second out-of-phase voice signals from at least one source voice signal.

[0021] According to one embodiment, the communication equipment is configured to phase shift by Pi at least one source voice signal in order to generate the first voice signal, and not to phase shift the source voice signal in order to generate the second voice signal.

[0022] It will be understood that the different modes of embodiment described above are configurations which allow emission in opposite phase, that is to say with a phase shift of Pi, in the right ear and the left ear in such a way that the summation of the sound taken in the right ear and the sound taken in the left ear eliminates the sound linked to the source voice signal.

[0023] According to one embodiment, at least one device, referred to as the sound environment reproduction device, of the first and second devices includes a second microphone, disposed on an external surface of the at least one sound environment reproduction device and directed outwards, the second microphone being configured to capture ambient noise and output an ambient noise source signal from the at least one sound environment reproduction device; the communication equipment being configured to generate an ambient noise signal corresponding to the at least one sound environment reproduction device from the ambient noise source signal; the communication equipment further includes,For each sound reproduction device: a second summing device configured to receive as input and sum the ambient noise signal corresponding to at least one sound reproduction device and the voice signal configured to be delivered to the loudspeaker of at least one sound reproduction device, and to output the sum to the loudspeaker of at least one sound reproduction device; a filtering module, connected to the second microphone, configured to receive the ambient noise signal corresponding to at least one sound reproduction device, to filter the ambient noise signal corresponding to at least one sound reproduction device by an estimated transfer function, and to output a filtered ambient noise signal; and a mixer,the first microphone of at least one sound reproduction device being further configured to capture, in the respective ear, a sound from the ambient noise signal corresponding to at least one sound reproduction device generated by the loudspeaker of at least one sound reproduction device, the mixer being configured to receive as input and to subtract the pre-output signal corresponding to at least one sound reproduction device and the filtered ambient noise signal, and to deliver as output the output signal corresponding to at least one sound reproduction device, the output signal corresponding to at least one sound reproduction device being equal to the pre-output signal corresponding to at least one sound reproduction device from which the filtered ambient noise signal is subtracted,and the output signal corresponding to at least one sound environment reproduction device being free of ambient noise signal component corresponding to at least one sound environment reproduction device; for each sound environment reproduction device, the estimated transfer function modeling an overall transfer function between the second summing unit and the mixer.

[0024] Implementing ambient sound reproduction prevents the user from being isolated from their surroundings, for example, to facilitate conversation with someone nearby who is not using a communication system or to enable faster detection of an audible alarm. Preferably, both devices in the communication equipment should be ambient sound reproduction devices.

[0025] The estimated transfer function models a "global" transfer function between the second summing mixer and the mixer, that is, along the entire path enabling the reproduction of the sound environment to the user, in order to eliminate the sound environment reproduction at the mixer level. The estimated transfer function models, in particular, a possible electronic loudspeaker power amplification circuit, the loudspeaker itself, the acoustic transfer function in the user's ear between the first microphone and the corresponding device's loudspeaker, and a possible post-microphone power amplification module.

[0026] According to one embodiment, the communication equipment further comprises, for each sound environment reproduction device, an adaptive gain module enabling the ambient noise signal source of at least one sound environment reproduction device to be attenuated before generating the ambient noise signal corresponding to at least one sound environment reproduction device intended to be transmitted to the loudspeaker of at least one sound environment reproduction device.

[0027] Attenuating the ambient noise signal reduces the sound level of the reproduced audio to prevent hearing damage to the user. To facilitate the elimination of the ambient noise component in the output signal of a sound reproduction device, the ambient noise signal is attenuated in the same way on both the ambient noise signal intended for the electronic filtering circuit and the ambient noise signal intended for the loudspeaker before any bifurcation. In one embodiment, the attenuation of the ambient noise signal from at least one sound reproduction device depends on a specific ambient noise level.

[0028] Modifying the attenuation based on the ambient noise level allows for optimizing the sound level of the sound environment reproduction while preventing damage to the user's hearing.

[0029] According to one embodiment, the communication equipment is configured such that the attenuation ensures that the sound level of the ambient noise signal corresponding to the at least one sound environment reproduction device generated by the loudspeaker of the at least one sound environment reproduction device is always below a threshold value.

[0030] Using a threshold value ensures that the user's hearing will not be impaired. Ideally, the communication equipment is configured so that the sound level at the user's eardrum is less than or equal to 75 dBA measured in a free field.

[0031] According to one embodiment, at least one operation performed by the communication equipment, on at least one source voice signal or on an intermediate signal between at least one source voice signal and the total output signal, is performed by a processor.

[0032] According to one embodiment, the total output signal processing module is implemented by at least one of a CPU, a microcontroller, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC). The equipment according to the invention is thus suitable for a significant computing load. In another embodiment, at least one of the first and second devices is an in-ear hearing protector.

[0033] The use of in-ear hearing protection isolates the user's ear canal from the outside, thus improving the quality of use of communication equipment.

[0034] The present invention also relates to a communication system capable of enabling a user to participate in full-duplex communication with at least one interlocutor with a sound pickup in the user's ear, characterized by the fact that the system comprises communication equipment as described above for the user, at least one user communication device for the user and at least one interlocutor communication device for each interlocutor, each user communication device being capable of communicating with at least one of the interlocutor devices, each user communication device being configured to transmit at least one source voice signal to the user communication equipment,and the user communication equipment being configured to output a total output signal intended to generate at least one return voice signal intended to be transmitted to at least one of the interlocuting communication devices by one of the user communication devices; the interlocutors possibly using communication equipment as described above.

[0035] According to one embodiment, at least one of the communication devices is one of a radio, a walkie-talkie, a telephone, a smartphone, a digital tablet or a computer.

[0036] A communication device according to an embodiment of the present invention and a communication system according to the present invention will now be described by way of non-limiting examples, with reference to the attached drawing.

[0037] In this drawing: [ Fig. 1 [ ] is a schematic functional representation of a communication device according to the present invention; the elements that enable the reproduction of the sound environment are represented by dotted lines. Fig. 2 ] is a schematic representation of a communication device according to a preferred embodiment of the present invention.

[0038] If we refer to the Figure 1 Figure 1 shows a communication device according to the present invention, comprising a first device 2, a second device 3, a first summing junction 4, and a source voice signal processing module 5. The first device 2 is designed to be inserted into a first ear O1 of a user, and the second device 3 is designed to be inserted into a second ear O2 of the user. According to the embodiment shown in the Figure 1 The first ear, O1, corresponds to the left ear, and the second ear, O2, corresponds to the right ear. Alternatively, the first ear, O1, could be the right ear, and the second ear, O2, the left ear. Preferably, the first device, 2, and the second device, 3, are in the form of in-ear hearing protection, but they can take the form of any type of device designed to be inserted into the user's ear, O1, O2, such as earphones or earbuds.

[0039] The first device 2 and the second device 3 each comprise a loudspeaker 21, 31 and a first microphone 22, 32 configured to be positioned, in use, opposite a respective ear canal of the user. The loudspeaker 21, 31 is configured to generate sounds in the respective ear O1, O2 and the first microphone 22, 32 is configured to capture sounds in the respective ear O1, O2.

[0040] The source voice signal processing module 5 is configured to receive a source voice signal p0 transmitted by a communication device, for example a radio, walkie-talkie, telephone, smartphone, tablet, or computer, and to generate, from the source voice signal p0, a first voice signal -p and a second voice signal p in opposite phase, i.e., out of phase by Pi or 180°. The first voice signal -p is delivered to the speaker 21 of the first device 2, and the second voice signal p is delivered to the speaker 31 of the second device 3.

[0041] According to the embodiment shown in the Figure 1 The source voice signal processing module 5 includes a phase shifter module 50, configured to phase shift by Pi, i.e. by 180°, the source voice signal p 0 received by the communication equipment 1 so as to generate a first voice signal -p intended for the first device 2, in opposite phase to the source voice signal p 0, and the source voice signal processing module 5 is configured not to phase shift the source voice signal p 0 in order to generate a second voice signal p intended for the second device 3. Those skilled in the art will understand that other solutions are possible, as alternatives, to obtain a first voice signal -p and a second voice signal p in opposite phase.For example, the source voice signal processing module 5 could be configured to phase shift by Pi, i.e. by 180°, the source voice signal p 0 received by the communication equipment 1 so as to generate a second voice signal, intended for the second device 3, in opposite phase to the source voice signal p 0, and the source voice signal processing module 5 would then be configured not to phase shift the source voice signal p 0 in order to generate a first voice signal intended for the first device 2.Alternatively, the source voice signal processing module 5 could include a first phase-shifting module configured to phase-shift the source voice signal p0 received by the communication equipment 1 by +Pi / 2, i.e., +90°, in order to generate the first voice signal. The source voice signal processing module 5 would then include a second phase-shifting module (not shown) configured to phase-shift the source voice signal p0 received by the communication equipment 1 by -Pi / 2, i.e., -90°, in order to generate the second voice signal. Alternatively, the first phase-shifting module could phase-shift the source voice signal p0 by -Pi / 2, and the second phase-shifting module (not shown) could phase-shift the source voice signal p0 by +Pi / 2. It will be understood that other combinations of phase shifts are possible in order to obtain a first voice signal -p and a second voice signal p in opposite phase.

[0042] Furthermore, as an alternative to the embodiment shown in the Figure 1 , the communication equipment 1 can be configured to receive two source voice signals p 0 , -p 0 in opposite phase transmitted by the communication device, such that one -p 0 of the two source voice signals p 0 , - p 0 is used as the first voice signal -p and is delivered to the loudspeaker 21 of the first device 2, and the other p 0 of the two source voice signals p 0 , -p 0 is used as the second voice signal p and is delivered to the loudspeaker 31 of the second device 3.

[0043] The communication equipment 1 may optionally receive source voice signals p 0 from several communication devices, in which case the source voice signal processing module 5 is configured to combine the different source voice signals p 0 received.

[0044] Preferably, the source voice signal processing module 5 is configured to calculate a sound level associated with the source voice signal p0. Even more preferably, the source voice signal processing module 5 is configured to allow adaptive adjustment of the gain of the source voice signal p0 before generating the voice signals -p, p, preferably based on a calculated sound level of the source voice signal p0.

[0045] The speaker 21 of the first device 2 is configured to generate at least one sound of the first voice signal -p, and the speaker 31 of the second device 3 is configured to generate at least one sound of the second voice signal p.

[0046] Preferably, the first speaker 21 and the second speaker 31 each include an electronic speaker power amplification circuit 23, 33, for example an amplifier, configured to adjust a power amplification of the signal entering the corresponding speaker 21, 31.

[0047] Preferably, the loudspeakers 21, 31 of the two devices 2, 3 are identical. Even more preferably, the power amplifiers of the loudspeaker power amplifier electronic circuits 23, 33 are identical for both loudspeakers 21, 31. It will be understood that if the loudspeakers 21, 31 are different, the power amplifiers are preferably adjusted so that the same signal generates the same sound for each loudspeaker 21, 31.

[0048] The first microphone 22 of the first device 2 is configured to at least capture, in the first ear O1 of the user, a voice s of the user and the sound of the first voice signal -p generated by the loudspeaker 21 of the first device 2 in order to deliver at output a sound recording signal ps 1 of the first device 2. The first microphone 32 of the second device 3 is configured to at least capture, in the second ear O2 of the user, the voice s of the user and the sound of the second voice signal p generated by the loudspeaker 31 of the second device 3, in order to deliver at output a sound recording signal ps 2 of the second device 3.

[0049] Preferably, the communication equipment 1 includes a post-microphone power amplification module 221, 321 for each device 2, 3, configured to adjust, respectively, a power amplification of the ps 4 sound pickup signal of the first device 2 and of the ps 2 sound pickup signal of the second device 3, in order to generate pre-output signals s 1 , s 2 corresponding, respectively, to the first device 2 and the second device 3.

[0050] It will be understood that if the communication equipment 1 does not include a post-microphone power amplification module 221, 321, then the pre-output signal s1, s2 is equal to the sound pickup signal ps1, ps2.

[0051] Preferably, the first microphones 22, 32 of the two devices 2, 3 are identical. Even more preferably, the power amplifications of the post-microphone power amplification modules 221, 321 are identical for the two sound pickup signals ps1, ps2. It will be understood that if the first microphones 22, 32 of the two devices 2, 3 are different, the power amplifications are preferably adjusted so that the same sound generates the same pre-output signal s1, s2, corresponding, respectively, to the first device 2 and the second device 3.

[0052] Furthermore, in practice, it may happen that the user's first ear O1 and second ear O2 have different characteristics. In this case, it is understood that, preferably, the power amplifications of the loudspeaker power amplification electronic circuits 23, 33 and the post-microphone power amplification modules 221, 321 are adjusted so that the communication equipment 1 is configured in such a way that, for each device 2, 3, the same "first signal" entering the loudspeaker 21, 31 generates the same pre-output signal s1, s2.

[0053] In particular, if we denote h1, respectively h2, the transfer function of the loudspeaker 21 of the first device 2, respectively the transfer function of the loudspeaker 31 of the second device 3, a1, respectively a2, the power amplification of a possible electronic loudspeaker power amplification circuit 23 of the loudspeaker 21 of the first device 2, respectively the power amplification of a possible electronic loudspeaker power amplification circuit 33 of the loudspeaker 31 of the second device 3, H1, respectively H2, the acoustic transfer function in the first ear O1 between the first microphone 22 and the loudspeaker 21, respectively the acoustic transfer function in the second ear O2 between the first microphone 32 and the loudspeaker 31, and Am1, respectively Am2, the power amplification of a possible power amplification module 221 associated with the first device 2,respectively the power amplification of a possible power amplification module 321 associated with the second device 3, then, preferably a 1 , A m1 , a 2 and A m2 are adjusted so that h 1 x a 1 x H 1 x A m1 = h 2 x a 2 x H 2 x A m2 = hxax H x A m .,

[0054] The communication equipment 1 is configured to generate an output signal x1 corresponding to the first device 2, and an output signal x2 corresponding to the second device 3. Furthermore, the first summing 4 is configured to sum the output signal x1 corresponding to the first device 2 and the output signal x2 corresponding to the second device 3 in order to obtain a total output signal x.

[0055] It can be specified that without reproduction of the sound environment, the output signal x 1 corresponding to the first device 2 is equal to the pre-output signal s 1 corresponding to the first device 2, and the output signal x 2 corresponding to the second device 3 is equal to the pre-output signal s 2 corresponding to the second device 3. This is different in the case of reproduction of the sound environment and this configuration will be described in detail later.

[0056] If we refer to the Figure 1 The operating principle of the invention can be mathematically illustrated, without reproducing the sound environment, by denoting c1 as the bone conduction transfer function for the first ear O1 of the user, and c2 as the bone conduction transfer function for the second ear O2 of the user, we then have: x = x 1 + x 2 = s 1 + s 2 either, x = ps 1 × A m 1 + ps 2 × A m 2, that is, x = ( s × c 1 - p × h 1 × a 1) × H 1 × A m 1 +( s × c 2 + p × h 2 × a 2) × H 2 × A m 2, that is, x = s × ( c 1 × H 1 × A m 1 + c 2 × H 2 × A m 2) - p × ( h 1 × a 1 × H 1 × A m 1) + p × ( h 2 × a 2 × H 2 × A m 2)

[0057] In a theoretical case, we can assume that the bone conduction speaker and the acoustic transfer function are identical for the first and second ear O1, O2, that is to say that c1 = c2 = c and that H1 = H2 = H, since the user's head is symmetrical, that the transfer functions of the loudspeakers 21, 31 are identical, that is to say that h1 = h2 = h, since the loudspeakers 21, 31 are identical, and that the power amplifications are identical, that is to say that a1 = a2 = a and Am1 = Am2 = Am.

[0058] We then obtain x = 2 × s × c × H × A m .

[0059] In practice, it may happen that the loudspeakers 21, 31 or the first microphones 22, 32 are not strictly identical, or that the characteristics of the user's right and left ears are slightly different. In this case, the communication equipment 1 is preferably configured to compensate for these differences, for example, by slightly adjusting the power amplification of the loudspeaker power amplification electronic circuits 23, 33 and the post-microphone power amplification modules 221, 321, such that h1 x a1 x H1 x Am1 = h2 x a2 x H2 x Am2 = hxax H x Am. Using the equation above, we therefore obtain: x = s × c 1 × H 1 × A m 1 + c 2 × H 2 × A m 2 ou x = s × H 1 × A m 1 × c 1 + c 2 × h 1 × a 1 h 2 × a 2 .

[0060] Thus, the total output signal is indeed free of the voice signal component -p, p, so that the communication equipment 1 enables an anti-echo function.

[0061] In the case of in-ear sound recording, due to the occlusion effect and bone conduction, the user's voice s, i.e., speech signal, is strongly amplified in the low-frequency range, particularly below 500 Hz. Preferably, the total output signal x is therefore processed before being transmitted to a communication device, using a total output signal processing module 6, in order to reduce the occlusion effect and the effect of bone conduction to make the sound of the user's voice s more natural for the interlocutor, and thus improve the quality and intelligibility of speech. These treatments are already known, for example from the following works: Elliott H. Berger, Ronald W. Kieper, Dan Gauger, “Hearing protection: Surpassing the limits to attenuation imposed by the bone-conduction pathways” (Hearing protection: Surpassing the limits of attenuation imposed by bone-conduction pathways) J.Acoust. Soc. Am., Vol. 114, No. 4, Pt. 1, October 2003, and will not be detailed here.

[0062] The total output signal processing module 6 may also optionally include an amplification module.

[0063] As depicted on the Figure 1 The communication equipment 1 may further include a function for reproducing the sound environment. According to the embodiment shown in the Figure 1 , each device 2, 3 further includes a second microphone 24, 34, and the communication equipment 1 further includes, for each device 2, 3, a second summing 25, 35, a filtering module 26, 36 and a mixer 27, 37, respectively.

[0064] The second microphones 24, 34 are arranged on an external surface of the corresponding device 2, 3 and are directed outwards during use. The second microphones 24, 34 are configured to capture sounds outside the communication equipment 1, including ambient noise, and to output an ambient noise signal from source brs 1 of the first device 2 and an ambient noise signal from source brs 2 of the second device 3.

[0065] For a reproduction of the sound environment, the second summing 25 associated with the first device 2 is configured to receive as input the first voice signal -p and an ambient noise signal br 1 corresponding to the first device 2, the ambient noise signal br 1 corresponds to the ambient noise source signal brs 1 of the first device 2 possibly adjusted in gain and corrected as will be detailed later, and to deliver the sum of these two signals to the loudspeaker 21 of the first device 2.Similarly, the second summing unit 35 associated with the second device 3 is configured to receive as input the second voice signal p and an ambient noise signal br 1 corresponding to the second device 3, the ambient noise signal br 2 corresponds to the ambient noise source signal brs 2 of the second device 3 possibly adjusted in gain and corrected as will be detailed later, and to deliver the sum of these two signals to the loudspeaker 31 of the second device 3.

[0066] In the case of a reproduction of the sound environment, the loudspeakers 21, 31 are configured to, in addition, generate a sound of the surrounding noise signal br 1, br 2 and the first microphones 22, 32 are configured to, in addition, capture in the respective ear O1, O2 the sound of the surrounding noise signal br 1, br 2 generated by the corresponding loudspeaker 21, 31.

[0067] The filtering module 26, 36 associated with each device 2, 3 is configured to receive as input the ambient noise signal br 1 , br 2 corresponding to said device 2, 3, and to deliver as output a filtered ambient noise signal brf 1 , brf 2 . The filtering is performed by an estimated transfer function ĥ 1 , ĥ 2 modeling a "global" transfer function between the second summing 25 associated with the first device 2, respectively the second summing 35 associated with the second device 3, and the mixer 27 associated with the first device 2, respectively the mixer 37 associated with the second device 3.The said "global" transfer function therefore preferably models the speaker power amplification electronic circuit 23 of the speaker 21 of the first device 2, respectively the speaker power amplification electronic circuit 33 of the speaker 31 of the second device 3, the speaker 21 of the first device 2, respectively the speaker 31 of the second device 3, the acoustic transfer function in the user's ear O1, O2 between the first microphone 22 of the first device 2, respectively the first microphone 32 of the second device 3, and the speaker 21 of the first device 2, respectively the speaker 31 of the second device 3, and the post-microphone power amplification module 221 associated with the first device 2, respectively the post-microphone power amplification module 321 associated with the second device 3.

[0068] For each filtering module 26, 36, the estimated transfer function ĥ1, ĥ2 is determined in advance, preferably based on the characteristics of the associated device 2, 3, for example, based on the type of in-ear protection, and the characteristics of the corresponding ear O1, O2 of the user, for example, based on the characteristics of the ear canal and tympanic membrane. The estimated transfer function ĥ1 of the filtering module 26 associated with the first device 2 may possibly differ from the estimated transfer function ĥ2 of the filtering module 36 associated with the second device 3.

[0069] The mixer 27 associated with the first device 2, respectively the mixer 37 associated with the second device 3, is configured to receive as input the pre-output signal s 1 corresponding to the first device 2, respectively the pre-output signal s 2 corresponding to the second device 3, to subtract from it the ambient noise signal filtered brf 1 by the filtering module 26 associated with the first device 2, respectively the ambient noise signal filtered brf 2 by the filtering module 36 associated with the second device 3, and to deliver as output the output signal x 1 corresponding to the first device 2, respectively the output signal x 2 corresponding to the second device 3.

[0070] Preferably, the communication equipment 1 further includes, for each device 2, 3, an associated adaptive gain module 28, 38. The adaptive gain module 28, 38 is configured to allow adaptive adjustment of the gain (maximum equal to 1) of the ambient noise source signal brs1, brs2, in order to allow, respectively, attenuation of the ambient noise source signal brs1 of the first device 2 and the ambient noise source signal brs2 of the second device 3, before generating, respectively, the ambient noise signal br1 corresponding to the first device 2 and the ambient noise signal br2 corresponding to the second device 3. As shown in the Figure 1 , the communication equipment 1 is configured such that the ambient noise signal attenuation source brs 1 , brs 2 is done, preferably, in the same way on the ambient noise signal br 1 , br 2 intended to be transmitted to the filtering module 26, 36 and on the ambient noise signal br 1 , br 2 intended to be transmitted to the loudspeaker 21 , 31.

[0071] Preferably, the communication equipment 1 further includes a sound level calculation module 7 configured to measure an ambient noise sound level based on the ambient noise signal br1 corresponding to the first device 2 and the ambient noise signal br2 corresponding to the second device 3, for example by averaging the sound levels measured for each of the two signals br1, br2. Preferably still, the communication equipment 1 is configured to define a gain g1, g2 of the adaptive gain modules 28, 38 as a function of the sound level calculated by the sound level calculation module 7.

[0072] Preferably, the adaptive gain modules 28, 38 are always identical, and the gain g 1 of the adaptive gain module 28 associated with the first device 2 is equal to the gain g 2 of the adaptive gain module 38 associated with the second device 3, in order to guarantee good perception of the sound environment.

[0073] Preferably, each adaptive gain module 28, 38 is configured so that the sound level of each ambient noise signal tone br1, br2 generated by the loudspeaker 21, 31 is less than or equal to a threshold value. Preferably, the threshold value is a maximum of 75 dBA free field reported.

[0074] Preferably, the communication equipment 1 further includes, for each device 2, 3, an associated correction module 281, 381, located downstream of the associated adaptive gain module 28, 38.

[0075] The correction module 281, 381 is configured to correct the gain-adjusted ambient noise source signal brs 1, brs 2 before generating the ambient noise signal br 1, br 2. This allows for correction of the gain-adjusted ambient noise source signal brs 1 of the first device 2 and the gain-adjusted ambient noise source signal brs 2 of the second device 3, respectively. The correction module 281, 381 is designed to achieve a flat insertion loss in the frequency range [100 Hz - 6 kHz], meaning that with or without protection, the low-level ambient noise should be identical in this frequency range.The correction of the ambient noise signal source brs 1, brs 2 allows, in particular, for the user to experience the sensation of an open ear, that is to say, a sensation similar to that experienced without device 2, 3 placed in the ear O1, O2, and to allow for more natural listening for the user when the sound of the ambient noise signal br 1, br 2 is generated by the speaker 21, 31 of the associated device 2, 3. As shown in the figure. Figure 1 , the communication equipment 1 is configured in such a way that the correction is made, preferably, in the same way for the ambient noise signal br 1 , br 2 intended to be transmitted to the filtering module 26, 36, and on the ambient noise signal br 1 , br 2 intended to be transmitted to the loudspeaker 21, 31.

[0076] In order to promote a homogeneous and natural reproduction of the sound environment between the two ears of the user, if we denote H n1 , respectively H n2 , the transfer function of a correction module 281 associated with the first device 2, respectively of a correction module 381 associated with the second device 3, then, preferably, H n1 , g 1 , a 1 , H n2 , g 2 and a 2 are adjusted so that h 1 x H n1 xg 1 xa 1 = h 2 x H n2 xg 2 xa 2 .

[0077] A person skilled in the art will understand that, as an alternative to the embodiment shown in the Figure 1 , the reproduction of the sound environment can also be implemented only for the first device 2 or only for the second device 3.

[0078] If we refer to the Figure 1 The operating principle of the invention can be mathematically illustrated, with the reproduction of the sound environment, as follows: x = x 1 + x 2

[0079] With, x 1= s 1 - brf 1 = ps 1 × A m 1 - br 1 × ĥ 1 And x 2 = s 2 - brf 2 = ps 2 × A m 2 - br 2 × ĥ 2 or x 1 = ( s × c 1 + ( br 1 - p ) × h 1 × a 1) × H 1 × A m 1 - br 1 × ĥ 1 and x 2 = ( s × c 2 + ( br 2 + p ) × h 2 × a 2) × H 2 × A m 2 - br 2 × ĥ 2

[0080] In a theoretical case, we can assume that the bone conduction speaker and the acoustic transfer function are identical for the first and second ear O1, O2, i.e. that c1 = c2 = c and that H1 = H2 = H, since the user's head is symmetrical, that the transfer functions of the loudspeakers 21, 31 are identical, i.e. that h1 = h2 = h, since the loudspeakers 21, 31 are identical, that the power amplifications are identical, i.e. that a1 = a2 = a and Am1 = Am2 = Am, and that the estimated transfer functions are identical, i.e. that ĥ1 = ĥ2 = ĥ, since the first 2 and second 3 devices and the first O1 and second O2 ears are identical. Furthermore, we can consider that the estimated transfer functions correspond to the "real" transfer functions, that is to say that ĥ = hxax H x A m .

[0081] We then obtain x 1 = s × c + br 1 − p × h × a × H × A m − br 1 × h × a × H × A m And x 2 =( s × c + ( br 2 + p ) × h × a ) × H × A m - br 2 × h × a × H × A m either x = 2 × s × c × H × A m .

[0082] In practice, it may happen that the loudspeakers 21, 31 or the first microphones 22, 32 are not strictly identical, or that the characteristics of the user's right and left ears are slightly different. In this case, the communication equipment 1 is preferably configured to compensate for these differences, for example, by slightly adjusting the power amplification of the loudspeaker power amplification electronic circuits 23, 33 and the post-microphone power amplification modules 221, 321, such that h1 x a1 x H1 x Am1 = h2 x a2 x H2 x Am2 = hxax H x Am. Furthermore, due to the modeling, there is often an error e between the estimated and "actual" transfer functions, i.e., ĥ = hxax H x Am + e.

[0083] Using the equations above, we obtain: x 1 = s × c 1 × H 1 × A m 1 + br 1 − p × h × a × H × A m − br 1 × h × a × H × A m + e And x 2 = s× c 2 × H 2 × A m 2 + ( br 2 + p ) × h × a × H × A m - br 2 × ( h × a × H × A m + e ) either x = s × ( c 1 × H 1 × A m 1 + c 2 × H 2 × A m 2) - ( br 1 + br 2) × e Or x = s × H 1 × A m 1 × c 1 + c 2 × h 1 × a 1 h 2 × a 2 − br 1 + br 2 × e

[0084] Thus, the total output signal x is indeed free from the voice signal component -p, p, so that the communication equipment 1 allows an anti-echo function, and the reproduction of the sound environment sent to the interlocutor is reduced to a minimum, insofar as the error e is small. As mentioned above, in the case of in-ear sound recording, due to the occlusion effect and bone conduction, the user's voice, i.e., speech signal, is strongly amplified in the low-frequency range, particularly below 500 Hz. Preferably, the total output signal x is therefore processed before being transmitted to a communication device, using the total output signal processing module 6, in order to reduce the occlusion effect and the effect of bone conduction, making the user's voice sound more natural to the listener, and thus improving speech quality and intelligibility.These treatments are already known, for example from the scientific publication mentioned above "Hearing protection: Surpassing the limits to attenuation imposed by the bone-conduction pathways", and will not be detailed here.

[0085] The total output signal processing module 6 may also optionally include an amplification module.

[0086] There Figure 2 schematically represents a communication device 1 according to a preferred embodiment of the invention. Figure 1 shows... Figure 2 that a large part of the operations performed, represented functionally on the Figure 1 , on intermediate signals, that is to say signals used by the communication equipment 1 between the at least one source voice signal and the total output signal and between the total output signal and the at least one return voice signal, are carried out by a processor Proc.

[0087] Thus, the first summing 4, the second summing 25, 35, and the mixers 27, 37 are preferably implemented by a processor programmed to perform these functions. However, it will be understood that, alternatively, the first summing 4, the second summing 25, 35, and the mixers 27, 37 could also be implemented by several processors or by one or more electronic circuits, including a microcontroller, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC).

[0088] Furthermore, the modules, including the source voice signal processing module 5, the phase shifting module 50, the total output signal processing module 6, the post-microphone power amplification modules 221, 321, the filtering modules 26, 36, the adaptive gain modules 28, 38, the correction modules 281, 381, and the sound level calculation module 7, are preferably implemented by a processor programmed to perform these functions. However, it should be understood that, alternatively, the modules could be implemented by several processors or by one or more electronic circuits, including a microcontroller, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), or an application-specific integrated circuit (ASIC).

[0089] As an alternative to the embodiment described above, it will be understood that the electronic power amplification circuits of the loudspeakers 23, 33 of the loudspeakers 21, 31 could also, alternatively, be implemented by one or more processors, or several microcontroller-type circuits, microprocessor, digital signal processor (DSP), field-programmable pre-diffused matrix (FPGA) or application-specific integrated circuit (ASIC).

[0090] The communication equipment is powered by at least one of the following: an integrated battery, a remote battery (wired power supply).

[0091] A communication device 1 according to the invention further enables the implementation of a communication system capable of allowing a user to participate in full-duplex communication with at least one other person, with the user receiving audio directly in their ear. Such a system comprises a communication device 1 according to the invention for the user, at least one user communication device for the user, and at least one interlocutor communication device for each other.Each user communication device is capable of communicating with at least one of the communicating devices. Each user communication device is configured to transmit at least one source voice signal p0, -p0 to the user communication device 1. The user communication device 1 is configured to output a total output signal x intended to generate at least one return voice signal prr, -prr intended to be transmitted to at least one of the communicating devices by one of the user communication devices. Preferably, the communicating devices also use a communication device 1 according to the invention.

[0092] Communication devices are chosen, for example, from a radio, a walkie-talkie, a telephone, a smartphone, a tablet, and a computer.

Claims

1. - A communication equipment (1) allowing full duplex with in-ear sound pickup, the communication equipment (1) being configured to receive at least one source speech signal (p0, -p0) transmitted by at least one communication apparatus and to provide a total output signal (x), the communication equipment (1) comprising: - a first device (2) intended to be inserted into one (01) from among a right ear and a left ear of a user, and - a second device (3) intended to be inserted into the other (O2) from among the right ear and the left ear of the user; - each from among the first device (2) and the second device (3) comprising a first microphone (22, 32) and a loudspeaker (21, 31) configured to be arranged, in use, facing an ear canal of the user; characterized in that: - the communication equipment (1) is configured in such a way that a first speech signal (-p) is provided to the loudspeaker (21) of the first device (2) and a second speech signal (p) is provided to the loudspeaker (31) of the second device (3), the first (-p) and second (p) speech signals being based on the at least one source speech signal (p0, -p0) in such a way that the first speech signal (-p) and the second speech signal (p) are in phase opposition, in other words, phase-shifted by Pi; - the first microphone (22, 32) of the first (2), respectively second (3), device is configured to pick up, in the respective ear (01, O2), at least one voice (s) of the user and one sound of the first (-p), respectively second (p), speech signal generated by the loudspeaker (21, 31) of the first (2), respectively second (3), device, and to output a sound pick-up signal (ps1, ps2) of the first (2), respectively second (3), device; - the communication equipment (1) is configured to generate a pre-output signal (s1) corresponding to the first device (2) and a pre-output signal (s2) corresponding to the second device (3), respectively, from the sound pick-up signal (ps1, ps2) of the first (2) and the second (3) devices, and to generate an output signal (x1) corresponding to the first device (2) and an output signal (x2) corresponding to the second device (3), comprising, respectively, at least one component related to the pre-output signal (s1) corresponding to the first device (2) and one component related to the pre-output signal (s2) corresponding to the second device (3); and - the communication equipment (1) further comprises a first summer (4) configured to receive as input and to sum the output signal (x1) of the first device (2) and the output signal (x2) of the second device (3), the first summer (4) outputting the total output signal (x) equal to the sum of the output signal (x1) of the first device (2) and the output signal (x2) of the second device (3), and the total output signal (x) comprising a voice component (s) of the user and being free of components of the first and second speech signals (-p, p).

2. - The communication equipment (1) according to claim 1, characterized in that the communication equipment (1) further comprises a total output signal processing module (6) configured to process the total output signal (x) in order to generate, from the total output signal (x), at least one from among a return speech signal (pr, -pr) and two return speech signals (pr, -pr) in phase opposition, the processing being at least one from among a reduction in the occlusion effect, a reduction in the bone transmission effect, and an amplification, in order to render the total output signal (x) more natural for the interlocutor.

3. - The communication equipment (1) according to any one of claims 1 and 2, characterized in that the communication equipment (1) is configured to receive two source speech signals (p0, -p0) in phase opposition coming from each communication apparatus, to use one (-p0) of the two source speech signals (p0, -p0) in order to generate the first speech signal (-p) and provide it to the loudspeaker (21) of the first device (2), and to use the other (p0) of the two source speech signals (p0, -p0) to generate the second speech signal (p) and provide it to the loudspeaker (31) of the second device (3).

4. - The communication equipment (1) according to any one of claims 1 and 2, characterized in that the communication equipment (1) comprises a source speech signal processing module (5) configured to receive a single source speech signal (p0) coming from each communication apparatus and to generate the first speech signal (-p) and the second speech signal (p) in phase opposition from the at least one source speech signal (p0).

5. - The communication equipment (1) according to claim 4, characterized in that the communication equipment (1) is configured to phase-shift by Pi, the at least one source speech signal (p0) in order to generate the first speech signal (-p), and not to phase-shift the source speech signal (p0) in order to generate the second speech signal (p).

6. - The communication equipment (1) according to any one of claims 1 to 5, characterized in that at least one device, referred to as a sound environment playback device, from among the first device (2) and the second device (3) comprises a second microphone (24, 34), arranged on an external surface of the at least one sound environment playback device and directed toward the exterior, the second microphone (24, 34) being configured to pick up an environmental noise and output an environmental noise source signal (brs1, brs2) to the at least one sound environment playback device; the communication equipment being configured to generate an environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device from the environmental noise source signal (brs1, brs2); the communication equipment (1) further comprises, for each sound environment playback device: - a second summer (25, 35) configured to receive as input and to sum the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device and the speech signal (-p, p) configured to be provided to the loudspeaker (21, 31) of the at least one sound environment playback device, and to output the sum to the loudspeaker (21, 31) of the at least one sound environment playback device; - a filter module (26, 36), connected to the second microphone (24, 34) configured to receive the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device, to filter the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device by an estimated transfer function (ĥ1, ĥ2), and to output a filtered environmental noise signal (brf1, brf2); and - a mixer (27, 37), the first microphone (22, 32) of the at least one sound environment playback device being further configured to pick up, in the respective ear (01, O2), a sound of the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device generated by the loudspeaker (21, 31) of the at least one sound environment playback device, the mixer (27, 37) being configured to receive as input and to subtract the pre-output signal (s1, s2) corresponding to the at least one sound environment playback device and the filtered environmental noise signal (brf1, brf2), and to output the output signal (x1, x2) corresponding to the at least one sound environment playback device, the output signal (x1, x2) corresponding to the at least one sound environment playback device being equal to the pre-output signal (s1, s2) corresponding to the at least one sound environment playback device from which the filtered environmental noise signal (brf1, brf2) is subtracted, and the output signal (x1, x2) corresponding to the at least one sound environment playback device being free of the environmental noise signal (br1, br2) component corresponding to the at least one sound environment playback device; for each sound environment playback device, the estimated transfer function (ĥ1, ĥ2) modeling a global transfer function between the second summer (25, 35) and the mixer (27, 37).

7. - The communication equipment (1) according to claim 6, characterized in that the communication equipment (1) further comprises, for each sound environment playback device, an adaptive gain module (28, 38) allowing to attenuate the environmental noise source signal (brs1, brs2) of the at least one sound environment playback device before generating the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device intended to be transmitted to the loudspeaker (21, 31) of the at least one sound environment playback device.

8. - The communication equipment (1) according to claim 7, characterized in that the attenuation of the environmental noise source signal (brs1, brs2) of the at least one sound environment playback device depends on a sound level of the environmental noise signal (br1, br2).

9. - The communication equipment (1) according to claim 7 or claim 8, characterized in that the communication equipment (1) is configured in such a way that the attenuation allows that the sound level of the environmental noise signal (br1, br2) corresponding to the at least one sound environment playback device generated by the loudspeaker (21, 31) of the at least one sound environment playback device is always below a threshold value.

10. - The communication equipment (1) according to any one of claims 1 to 9, characterized in that at least one operation executed by the communication equipment (1), on the at least one source speech signal (p0, -p0) or on an intermediate signal between the at least one source speech signal (p0, -p0) and the total output signal (x), is executed by a processor (Proc.).

11. - The communication equipment (1) according to any one of claims 1 to 10, characterized in that the total output signal processing module (6) is implemented by at least one from among a processor (Proc), a microcontroller, a microprocessor, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC).

12. - The communication equipment (1) according to any one of claims 1 to 11, characterized in that at least one from among the first device (2) and the second device (3) is an in-ear hearing protector.

13. - A communication system able to allow a user to participate in full duplex communication with at least one interlocutor with in-ear sound pickup for the user, characterized in that the system comprises a communication equipment (1) according to any one of claims 1 to 12 for the user, at least one user communication apparatus for the user and at least one interlocutor communication apparatus for each interlocutor, each user communication apparatus being able to communicate with at least one of the interlocutor apparatuses, each user communication apparatus being configured to transmit at least one source speech signal (p0, -p0) to the user communication equipment (1), and the user communication equipment (1) being configured to output a total output signal (x) intended to generate at least one return speech signal (pr, -pr) intended to be transmitted to at least one of the interlocutor communication apparatuses by one of the user communication apparatuses; the interlocutors possibly using a communication equipment (1) according to any one of claims 1 to 12.

14. - The system according to claim 13, characterized in that at least one of the communication apparatuses is one from among a radio, a walkie-talkie, a telephone, a smart phone, a digital tablet and a computer.