System and method for amplifying an acoustic instrument using amplitude envelope cross correlation of multiple sensors

Abstract

An acoustic instrument amplification system may include an audio signal amplification device. The audio signal amplification device may include a pickup input terminal in pickup input signal receiving communication with a pickup mounted to an acoustic instrument. The audio signal amplification device may further include a primary microphone input terminal in primary microphone input signal receiving communication with a primary microphone. The audio signal amplification device may further include an envelope follower to receive a first follower input signal and to output a first gain control signal based on amplitude of the first follower input signal. The audio signal amplification device may further include a primary gain stage output signal based on the first primary gain stage input signal and based on the first gain control signal. The audio signal amplification device may further include a pickup crossover, audio crossovers, signal conditioners, and a secondary microphone.

Description

SYSTEM AND METHOD FOR AMPLIFYING AN ACOUSTIC INSTRUMENT USING AMPLITUDE ENVELOPE CROSS CORRELATION OF MULTIPLE SENSORSRELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 745,303 filed January 14, 2025, the content of which is incorporated by this reference in its entirety for all purposes as if fully set forth herein.TECHNICAL FIELD

[0002] The present disclosure relates generally to the field of systems and methods for amplifying acoustic instruments.BACKGROUND

[0003] The amplification of acoustic instruments, particularly in live performance settings, presents a complex challenge requiring a careful balance between sound fidelity, feedback rejection, and operational simplicity. Piezoelectric pickups have long been the preferred solution in such environments due to their low cost, straightforward design, and, crucially, their superior feedback rejection and resistance to unwanted resonances. These pickups function by converting mechanical vibrations from the instrument’s body into an electrical signal. However, despite their widespread use, piezoelectric pickups exhibit inherent limitations in terms of audio fidelity.

[0004] While microphones are widely recognized as the most accurate means of capturing the sound of acoustic instruments, their use in live performance environments is often impractical. Microphones are capable of recording a broad dynamic range and capturing the harmonic content generated within the instrument’s acoustic cavity. However, when used in loud performance settings, microphones are highly susceptible to feedback, a significant challenge for live amplification. Additionally, the requirement for performers to remain stationary while usingmicrophones further limits their practicality, particularly for artists who require mobility on stage.

[0005] Efforts to improve the fidelity of piezoelectric systems while preserving their advantages, such as feedback rejection and resistance to resonances, have typically focused on combining piezoelectric pickups with additional sensors, including microphones, or employing advanced signal processing techniques. Internal microphones have been proposed as an alternative to external microphones, but such configurations are often limited by feedback and resonance caused by the microphone’s position within the instrument. To mitigate these challenges, internal microphones are commonly paired with pickups, such as undersaddle or magnetic types. While this hybrid approach has shown some success, the role of the microphone is often minimized to prevent feedback, thereby limiting its effectiveness.

[0006] Several systems have been conventionally proposed which attempt to improve the fidelity of acoustic instrument amplification, including those discussed in the present section below.

[0007] U.S. Patent No. 6,822,156 (referred to below as Pl) appears to disclose, at least in part, a system that integrates a piezoelectric pickup with a cable sensor designed to capture ambient sounds, thereby attempting to enhance fidelity by introducing non body vibrational acoustic input.

[0008] U.S. Patent No. 7,271,332 (referred to below as P2), appears to disclose, at least in part, a system that combines two sensors, one optimized for low frequencies and the other for high frequencies, with the output being a blend of these frequencies. This approach apparently aims to provide a more balanced frequency response and improved harmonic content.

[0009] U.S. Patent No. 8,989,399 (referred to below as P3), appears to disclose, at least in part, a system incorporating a specially designed microphone, tuned for the specific instrument, which is mixed with a piezoelectric pickup and processed through signal conditioning techniques. The objective of this system appears to be to combine the strengths ofboth sensors to improve the overall sound.

[0010] U.S. Patent No. 11,501,745 (referred to below as P4), appears to disclose, at least in part, a system involving a digital filter designed to capture the frequency response of an external microphone, compare it to that of the onboard piezoelectric pickup, and apply a digital filter to the piezoelectric signal in an attempt to approximate the microphone’s frequency response, thereby enhancing the sound quality of the piezoelectric pickup.

[0011] Despite these prior advancements, the systems disclosed to date appear to primarily attempt to improve audio fidelity by either blending piezoelectric pickups and microphones to varying degrees or by heavily processing the piezoelectric signal. These approaches often result in an unnatural sound due to the fundamentally different sensitivities of the two systems. A piezoelectric pickup, being primarily a contact vibration sensor, has a limited dynamic range, leading to compression of the sound. This limitation is especially noticeable when attempting to capture the differences in sound between soft and hard plucks, as the piezoelectric sensor cannot fully capture the harmonic content generated within the instrument’s acoustic cavity by sound wave propagation through the air. In contrast, a microphone captures a broader dynamic range and accurately records the harmonics generated in the air.

[0012] While Pl and P2 provide some improvement in audio fidelity, the results are still not on par with the fidelity achievable through a microphone alone. In P4, while the frequency response of the piezoelectric sensor is digitally processed to approximate that of a microphone, it still lacks the necessary dynamic range and harmonic content, resulting in a processed and unnatural sound. P3 may be considered the most promising approach; however, it is still limited by the positioning of the microphone. Based on its disclosed configuration, the microphone functions more as a vibration sensor rather than an air pressure sensor, preventing it from fully capturing the harmonic content of the instrument. Furthermore, the use of a specially mounted and tuned microphone increases the complexity and cost of the system, making it difficult to install or retrofit in existing instruments.

[0013] To address these limitations, there remains a need for a system that accuratelyreproduces the full harmonic content of the acoustic instrument, similar to an external microphone, and offers a dynamic range comparable to that of a microphone. Such a needed system should also provide exceptional immunity to feedback and noise, akin to the performance of a piezoelectric pickup. Moreover, certain preferred implementations of such a needed system should be easy to manufacture, install, retrofit, and be economically viable.SUMMARY

[0014] The present inventor has discovered that focusing on the dynamics of the sensors, rather than the frequency response as in previous attempts, is useful in successfully developing a system that (a) accurately reproduces the full harmonic content of the acoustic instrument, similar to an external microphone, and offers a dynamic range comparable to that of a microphone, (b) provides exceptional immunity to feedback and noise, akin to the performance of a piezoelectric pickup, and (c) is easy to manufacture, install, retrofit, and is economically viable.

[0015] Certain implementations of the innovations disclosed herein may employ a combination of at least one internal microphone sensor, used to capture the most accurate frequency response, harmonic content, and dynamic range, along with at least one piezoelectric sensor acting as an envelope guide for the microphone sensor, in a manner which is both feasible and effective. This outcome may be achieved in certain implementations by dynamically analyzing the piezoelectric signal using an envelope follower, and applying the output of the analyzer to the microphone signal through a signal multiplication mechanism.

[0016] The result of certain implementations of the innovative systems, devices and methods of the present disclosure is an output signal that achieves near-perfect frequency response and harmonic content, as it is fully captured by the microphone and not blended with the piezoelectric signal. Additionally, the system may maintain the same level of robustness against feedback and undesired resonances, as the overall envelope level may be controlled by the piezoelectric signal, acting as a "gas pedal" for the microphone, inherently blocking feedback and resonances as those are not present in the piezoelectric signal.

[0017] A key advantage of particular implementations of the innovative systems, devices and methods of the present disclosure is that they may eliminate the need for specially developed or precisely positioned microphones. In other words, a standard, economical microphone can be used effectively.

[0018] Furthermore, in certain implementations of the innovative systems, devices and methods of the present disclosure, more than one microphone can be used, positioned at various locations within the instrument, with the microphone signals mixed together and controlled by the same envelope follower. This allows for an easy way to enhance frequency and harmonic content while eliminating concerns about undesirable resonances.

[0019] Additionally, the innovative systems, devices and methods of the present disclosure can be implemented in analog, digital, or mixed domains, further enhancing ease of use and economic viability.

[0020] According to particular implementations of the of the present disclosure, the envelope control signal may also possess inherent characteristics that block undesirable white noise, reverb, and impact noises. As a result, even when the microphone picks up long sound tails such as reverb, white noise, or impact noises, such as the musician’s hand striking the instrument’s body, the output signal will not contain these unwanted signals, as the piezo envelope analyzer output would be significantly low for such events.

[0021] Certain implementations in accordance with the present disclosure include a piezoelectric sensor and a microphone, both mounted as integral components of the instrument. The microphone and piezoelectric sensor may be connected to a signal processing block, where an envelope follower block analyzes the signal from the piezoelectric sensor, and a gain stage block multiplies the microphone signal by the output of the envelope follower block.

[0022] Other implementations of the system may include two microphones mounted at different locations on the instrument, with each microphone being controlled by its own gainstage block. All gain stage blocks are then controlled by the output of the envelope follower block analyzer.

[0023] In certain implementations of the system, the envelope follower is divided into three frequency bands, each analyzing a subset of the spectrum, thereby controlling three gain stages that manage different portions of the microphone’s frequency spectrum.

[0024] In particular implementations of the system, the envelope follower output is passed through a comparator, where if the signal falls below a certain threshold, the control signal is clamped to zero, effectively eliminating unwanted low-level noise.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description of the preferred embodiments and upon reference to the accompanying drawings in which:

[0026] FIG. l is a block diagram illustrating the basic principle of operation of one nonlimiting implementation of a system in accordance with the present disclosure;

[0027] FIG. 2 illustrates the basic functionalities of a common envelope follower analyzer;

[0028] FIG. 3A is a block diagram illustrating a more advanced non-limiting implementation of a system in accordance with the present disclosure;

[0029] FIG. 3B is a block diagram illustrating a further non-limiting implementation of a system in accordance with the present disclosure, where two microphones are combined and a mixer block is added before the output to allow any combination of pickup input and processed microphones input to be present at the output;

[0030] FIG. 4A illustrates one non-limiting example of a hardware configuration in accordance with the present disclosure;

[0031] FIG. 4B illustrates a non-limiting example of a hardware configuration in accordance with the present disclosure;

[0032] FIG. 5 is a flow diagram illustrating a plurality of steps for one example implementation of an acoustic instrument amplification method;

[0033] FIG. 6 is a flow diagram illustrating a plurality of steps for one example implementation of an acoustic instrument amplification method;

[0034] FIG. 7 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6;

[0035] FIG. 8 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6;

[0036] FIG. 9 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6;

[0037] FIG. 10 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6;

[0038] FIG. 11 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6; and

[0039] FIG. 12 is a flow diagram illustrating a subset of steps for the acoustic instrument amplification method of FIG. 6.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Referring now to the drawings, like reference numerals designate identical or corresponding features throughout the several views.

[0041] Features of particular examples of an acoustic instrument amplification system 100, audio signal amplification device 104 and associated acoustic instrument amplification methods in accordance with the present disclosure are disclosed herein. This specification includes any claims submitted concurrently as part of this application.

[0042] With reference to the several drawings, implementations of an amplification system are shown generally at 100. The amplification system 100 may also be referred to herein as the system 100. Implementations of an audio signal amplification device are shown generally at 104. The audio signal amplification device 104 may also be referred to herein as the device 104. Implementations of an acoustic instrument amplification method are shown generally at 400. The acoustic instrument amplification method 400 may also be referred to herein as the method 400.

[0043] Referring to FIGS. 1, 3A-3B, and 4a, certain implementations of an amplification system 100 may comprise an audio signal amplification device 104.

[0044] The audio signal amplification device 104 may comprise a pickup input terminal 106. The pickup input terminal 106 may be configured to be in pickup input signal 200 receiving communication with a pickup 114 mounted to an acoustic instrument 102.

[0045] The audio signal amplification device 104 may comprise a primary microphone input terminal 108. The primary microphone input terminal 108 may be configured to be in microphone input signal 202 receiving communication with a microphone 116.

[0046] The audio signal amplification device 104 may comprise a first envelope follower 120a. The first envelope follower 120a may be configured to receive a first follower input signal206a. The first envelope follower 120a may be configured to output a first gain control signal 208a based on an amplitude envelope 302 of the first follower input signal 206a.

[0047] The audio signal amplification device 104 may comprise a first primary microphone gain stage 122a. The first primary microphone gain stage 122a may be configured to receive a first primary gain stage input signal 210a. The first primary microphone gain stage 122a may be configured to output a first primary gain stage output signal 212a based on the first primary gain stage input signal 210a and based on the first gain control signal 208a.

[0048] In certain implementations of the amplification system 100, the pickup 114 may be configured to sense vibration of the acoustic instrument 102 to which the pickup 114 is mounted independently of airborne sound.

[0049] In particular implementations of the amplification system 100, the first follower input signal 206a may include at least a portion of the pickup input signal 200.

[0050] In certain implementations of the amplification system 100, the first primary gain stage input signal 210a may include at least a portion of the microphone input signal 202.

[0051] In certain implementations of the amplification system 100, the audio signal amplification device 104 may be configured such that the first follower input signal 206a includes the entire pickup input signal 200.

[0052] In particular implementations of the amplification system 100, the audio signal amplification device 104 may be configured such that the first primary gain stage input signal 210a includes the entire microphone input signal 202.

[0053] Referring to FIGS. 3A-3B, in certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a pickup crossover 130. The pickup crossover 130 may be configured to split the pickup input signal 200 into at least a first pickup input sub-band signal 214a and a second pickup input sub-band signal 214b.

[0054] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary audio crossover 126. The primary audio crossover 126 may be configured to split the microphone input signal 202 into at least a first primary microphone input sub-band signal 216a and a second primary microphone input sub-band signal 216b.

[0055] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a second envelope follower 120b. The second envelope follower 120b may be configured to receive a second follower input signal 206b. The second envelope follower 120b may be configured to output a second gain control signal 208b based on an amplitude envelope 302 of the second follower input signal 206b.

[0056] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a second primary microphone gain stage 122b. The second primary microphone gain stage 122b may be configured to receive a second primary gain stage input signal 210b. The second primary microphone gain stage 122b may be configured to output a second primary gain stage output signal 212b based on the second primary gain stage input signal 210b and based on the second gain control signal 208b.

[0057] In certain implementations of the amplification system 100, the first follower input signal 206a may include the first pickup input sub-band signal 214a.

[0058] In particular implementations of the amplification system 100, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0059] In certain implementations of the amplification system 100, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0060] In particular implementations of the amplification system 100, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal216b.

[0061] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary summer 132. The primary summer 132 may be configured to produce a primary summed output signal 218 based on adding together the first primary gain stage output signal 212a and the second primary gain stage output signal 212b.

[0062] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary signal conditioner 138. The primary signal conditioner 138 may be configured to condition the primary summed output signal 218 and thereby produce a primary conditioned output signal 220.

[0063] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a pickup crossover 130. The pickup crossover 130 may be configured to split the pickup input signal 200 into at least a first pickup input subband signal 214a, a second pickup input sub-band signal 214b, and a third pickup input sub-band signal 214c.

[0064] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary audio crossover 126. The primary audio crossover 126 may be configured to split the microphone input signal 202 into at least a first primary microphone input sub-band signal 216a, a second primary microphone input subband signal 216b, and a third primary microphone input sub-band signal 216c.

[0065] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a second envelope follower 120b. The second envelope follower 120b may be configured to receive a second follower input signal 206b. The second envelope follower 120b may be configured to output a second gain control signal 208b based on an amplitude envelope 302 of the second follower input signal 206b.

[0066] In particular implementations of the amplification system 100, the audio signalamplification device 104 may further comprise a second primary microphone gain stage 122b. The second primary microphone gain stage 122b may be configured to receive a second primary gain stage input signal 210b. The second primary microphone gain stage 122b may be configured to output a second primary gain stage output signal 212b based on the second primary gain stage input signal 210b and based on the first gain control signal 208a.

[0067] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a third envelope follower 120c. The third envelope follower 120c may be configured to receive a third follower input signal 206c. The third envelope follower 120c may be configured to output a third gain control signal 208c based on an amplitude envelope 302 of the third follower input signal 206c.

[0068] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a third primary microphone gain stage 122c. The third primary microphone gain stage 122c may be configured to receive a third primary gain stage input signal 210c. The third primary microphone gain stage 122c may be configured to output a third primary gain stage output signal 212c based on the third primary gain stage input signal 210c and based on the third gain control signal 208c.

[0069] In certain implementations of the amplification system 100, the first follower input signal 206a may include the first pickup input sub-band signal 214a.

[0070] In particular implementations of the amplification system 100, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0071] In certain implementations of the amplification system 100, the third follower input signal 206c may include the third pickup input sub-band signal 214c.

[0072] In particular implementations of the amplification system 100, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0073] In certain implementations of the amplification system 100, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal 216b.

[0074] In particular implementations of the amplification system 100, the third primary gain stage input signal 210c may include the third primary microphone input sub-band signal 216c.

[0075] Referring to FIG. 3B, in certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a secondary microphone input terminal 110. The secondary microphone input terminal 110 may be configured to be in microphone input signal 204 receiving communication with a microphone 118.

[0076] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a secondary audio crossover 128. The secondary audio crossover 128 may be configured to split the microphone input signal 204 into at least a first secondary microphone input sub-band signal 222a, a second secondary microphone input sub-band signal 222b, and a third secondary microphone input sub-band signal 222c.

[0077] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a first secondary microphone gain stage 124a. The first secondary microphone gain stage 124a may be configured to receive a first secondary gain stage input signal 224a. The first secondary microphone gain stage 124a may be configured to output a first secondary gain stage output signal 226a based on the first secondary gain stage input signal 224a and based on the first gain control signal 208a.

[0078] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a second secondary microphone gain stage 124b. The second secondary microphone gain stage 124b may be configured to receive a second secondary gain stage input signal 224b. The second secondary microphone gain stage 124b maybe configured to output a second secondary gain stage output signal 226b based on the second secondary gain stage input signal 224b and based on the second gain control signal 208b.

[0079] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a third secondary microphone gain stage 124c. The third secondary microphone gain stage 124c may be configured to receive a third secondary gain stage input signal 224c. The third secondary microphone gain stage 124c may be configured to output a third secondary gain stage output signal 226c based on the third secondary gain stage input signal 224c and based on the third gain control signal 208c.

[0080] In particular implementations of the amplification system 100, the first follower input signal 206a may include the first pickup input sub-band signal 214a.

[0081] In certain implementations of the amplification system 100, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0082] In particular implementations of the amplification system 100, the third follower input signal 206c may include the third pickup input sub-band signal 214c.

[0083] In certain implementations of the amplification system 100, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0084] In particular implementations of the amplification system 100, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal 216b.

[0085] In certain implementations of the amplification system 100, the third primary gain stage input signal 210c may include the third primary microphone input sub-band signal 216c.

[0086] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a secondary summer 134. The secondary summer134 may be configured to produce a secondary summed output signal 228 based on adding together the first secondary gain stage output signal 226a, the second secondary gain stage output signal 226b, and the third secondary gain stage output signal 226c.

[0087] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary signal conditioner 138. The primary signal conditioner 138 may be configured to condition the primary summed output signal 218 and thereby produce a primary conditioned output signal 220.

[0088] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a secondary signal conditioner 140. The secondary signal conditioner 140 may be configured to condition the secondary summed output signal 228 and thereby produce a secondary conditioned output signal 230.

[0089] In particular implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a primary-secondary summer 136. The primarysecondary summer 136 may be configured to produce a combined processed output signal 232 based on adding together the primary conditioned output signal 220 and the secondary conditioned output signal 230.

[0090] In certain implementations of the amplification system 100, the audio signal amplification device 104 may further comprise a mixer 142. The mixer 142 may be configured to produce a mixed audio output signal 234 based on the pickup input signal 200 and the combined processed output signal 232.

[0091] In particular implementations of the amplification system 100, the pickup 114 may comprise a piezoelectric sensor.

[0092] In certain implementations of the amplification system 100, the pickup 114 may comprise an accelerometer.

[0093] In particular implementations of the amplification system 100, the pickup 114 may comprise an optical sensor.

[0094] In certain implementations of the amplification system 100, the pickup 114 may comprise aMEMS device.

[0095] In particular implementations of the amplification system 100, the pickup 114 may be mounted to an internal surface 152 of the acoustic instrument 102.

[0096] In certain implementations of the amplification system 100, the pickup 114 may be mounted under a saddle 103 of the acoustic instrument 102.

[0097] In particular implementations of the amplification system 100, the microphone 116 may be mounted within the acoustic instrument 102.

[0098] In certain implementations of the amplification system 100, the pickup input signal 200 may be configured to control at least a 100 hertz wide portion of a frequency spectrum of the microphone input signal 202.

[0099] In particular implementations of the amplification system 100, the microphone 116 may comprise an electret microphone.

[0100] In certain implementations of the amplification system 100, the pickup input signal 200 may include a minimum threshold level below which no gain control signal 208a, 208b, or 208c is output.

[0101] Referring to FIGS. 4A-4B, in particular implementations of the amplification system 100, the audio signal amplification device 104 may be disposed within the acoustic instrument 102.

[0102] In certain implementations of the amplification system 100, the audio signalamplification device 104 and the microphone 116 may be mounted on a printed circuit board disposed within the acoustic instrument 102.

[0103] In particular implementations of the amplification system 100, the audio signal amplification device 104 may be disposed externally to the acoustic instrument 102.

[0104] In certain implementations of the amplification system 100, the acoustic instrument 102 may comprise a guitar.

[0105] Referring to FIGS. 5-12, particular implementations of an acoustic instrument amplification method 400 may comprise a plurality of steps represented by blocks 405-436.

[0106] Certain implementations of an acoustic instrument amplification method 400 may include the system 100 as described herein, for example, by way of a step of providing the system 100. Particular implementations of an acoustic instrument amplification method 400 may include the device 104 as described herein, for example, by way of a step of providing the device 104.

[0107] Particular implementations of an acoustic instrument amplification method 400 may comprise, at block 405, receiving a pickup input signal 200 from a pickup 114 mounted to an acoustic instrument 102.

[0108] The acoustic instrument amplification method 400 may comprise, at block 415, receiving a primary microphone input signal 202 from a primary microphone 116.

[0109] The acoustic instrument amplification method 400 may comprise, at block 410, by way of a first envelope follower 120a, receiving a first follower input signal 206a and outputting a first gain control signal 208a based on an amplitude envelope 302 of the first follower input signal 206a.

[0110] The acoustic instrument amplification method 400 may comprise, at block 420,by way of a first primary microphone gain stage 122a, receiving a first primary gain stage input signal 210a and outputting a first primary gain stage output signal 212a based on the first primary gain stage input signal 210a and based on the first gain control signal 208a.[OHl] In certain implementations of the acoustic instrument amplification method 400, the pickup 114 may be configured to sense vibration of the acoustic instrument 102 to which the pickup 114 is mounted independently of airborne sound.

[0112] In particular implementations of the acoustic instrument amplification method 400, the first follower input signal 206a may include at least a portion of the pickup input signal 200.

[0113] In certain implementations of the acoustic instrument amplification method 400, the first primary gain stage input signal 210a may include at least a portion of the microphone input signal 202.

[0114] In certain implementations of the acoustic instrument amplification method 400, the first follower input signal 206a may include an entirety of the pickup input signal 200.

[0115] In particular implementations of the acoustic instrument amplification method 400, the first primary gain stage input signal 210a may include an entirety of the microphone input signal 202.

[0116] Certain implementations of the acoustic instrument amplification method 400 may comprise, at block 406b, by way of a pickup crossover 130, splitting the pickup input signal 200 into at least a first pickup input sub-band signal 214a and a second pickup input sub-band signal 214b.

[0117] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 416b, by way of a primary audio crossover 126, splitting the microphone input signal 202 into at least a first primary microphone input sub-band signal 216aand a second primary microphone input sub-band signal 216b.

[0118] Certain implementations of the acoustic instrument amplification method 400 may further comprise, at block 411, by way of a second envelope follower 120b, receiving a second follower input signal 206b and outputting a second gain control signal 208b based on an amplitude envelope 302 of the second follower input signal 206b.

[0119] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 421, by way of a second primary microphone gain stage 122b, receiving a second primary gain stage input signal 210b and outputting a second primary gain stage output signal 212b based on the second primary gain stage input signal 210b and based on the second gain control signal 208b.

[0120] In certain implementations of the acoustic instrument amplification method 400, the first follower input signal 206a may include the first pickup input sub-band signal 214a.

[0121] In particular implementations of the acoustic instrument amplification method 400, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0122] In certain implementations of the acoustic instrument amplification method 400, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0123] In particular implementations of the acoustic instrument amplification method 400, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal 216b.

[0124] Certain implementations of the acoustic instrument amplification method 400 may further comprise, at block 423, by way of a primary summer 132, producing a primary summed output signal 218 based on adding together the first primary gain stage output signal212a and the second primary gain stage output signal 212b.

[0125] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 424, by way of a primary signal conditioner 138, conditioning the primary summed output signal 218 and thereby producing a primary conditioned output signal 220.

[0126] Certain implementations of the acoustic instrument amplification method 400 may further comprise, at block 406a, by way of a pickup crossover 130, splitting the pickup input signal 200 into at least a first pickup input sub-band signal 214a, a second pickup input sub-band signal 214b, and a third pickup input sub-band signal 214c.

[0127] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 416a, by way of a primary audio crossover 126, splitting the microphone input signal 202 into at least a first primary microphone input sub-band signal 216a, a second primary microphone input sub-band signal 216b, and a third primary microphone input sub-band signal 216c.

[0128] Certain implementations of the acoustic instrument amplification method 400 may further comprise, at block 411, by way of a second envelope follower 120b, receiving a second follower input signal 206b and outputting a second gain control signal 208b based on an amplitude envelope 302 of the second follower input signal 206b.

[0129] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 421, by way of a second primary microphone gain stage 122b, receiving a second primary gain stage input signal 210b and outputting a second primary gain stage output signal 212b based on the second primary gain stage input signal 210b and based on the first gain control signal 208a.

[0130] Certain implementations of the acoustic instrument amplification method 400 may further comprise, at block 412, by way of a third envelope follower 120c, receiving a thirdfollower input signal 206c and outputting a third gain control signal 208c based on an amplitude envelope 302 of the third follower input signal 206c.

[0131] Particular implementations of the acoustic instrument amplification method 400 may further comprise, at block 422, by way of a third primary microphone gain stage 122c, receiving a third primary gain stage input signal 210c and outputting a third primary gain stage output signal 212c based on the third primary gain stage input signal 210c and based on the third gain control signal 208c.

[0132] In certain implementations of the acoustic instrument amplification method 400, the first follower input signal 206a may include the first pickup input sub-band signal 214a.

[0133] In particular implementations of the acoustic instrument amplification method 400, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0134] In certain implementations of the acoustic instrument amplification method 400, the third follower input signal 206c may include the third pickup input sub-band signal 214c.

[0135] In particular implementations of the acoustic instrument amplification method 400, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0136] In certain implementations of the acoustic instrument amplification method 400, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal 216b.

[0137] In particular implementations of the acoustic instrument amplification method 400, the third primary gain stage input signal 210c may include the third primary microphone input sub-band signal 216c.

[0138] Certain implementations of the method 400 may further comprise, at block 423, by way of a primary summer 132, producing a primary summed output signal 218 based on adding together the first primary gain stage output signal 212a, the second primary gain stage output signal 212b, and the third primary gain stage output signal 212c.

[0139] Certain implementations of the method 400 may further comprise, at block 425, receiving a secondary microphone input signal 204 from a secondary microphone 118.

[0140] Certain implementations of the method 400 may further comprise, at block 426, by way of a secondary audio crossover 128, splitting the secondary microphone input signal 204 into at least a first secondary microphone input sub-band signal 222a, a second secondary microphone input sub-band signal 222b, and a third secondary microphone input sub-band signal 222c.

[0141] Certain implementations of the method 400 may further comprise, at block 430, by way of a first secondary microphone gain stage 124a, receiving a first secondary gain stage input signal 224a and outputting a first secondary gain stage output signal 226a based on the first secondary gain stage input signal 224a and based on the first gain control signal 208a.

[0142] Certain implementations of the method 400 may further comprise, at block 431, by way of a second secondary microphone gain stage 124b, receiving a second secondary gain stage input signal 224b and outputting a second secondary gain stage output signal 226b based on the second secondary gain stage input signal 224b and based on the second gain control signal 208b.

[0143] Certain implementations of the method 400 may further comprise, at block 432, by way of a third secondary microphone gain stage 124c, receiving a third secondary gain stage input signal 224c and outputting a third secondary gain stage output signal 226c based on the third secondary gain stage input signal 224c and based on the third gain control signal 208c.

[0144] In certain implementations of the method 400, the first follower input signal 206amay include the first pickup input sub-band signal 214a.

[0145] In particular implementations of the method 400, the second follower input signal 206b may include the second pickup input sub-band signal 214b.

[0146] In certain implementations of the method 400, the third follower input signal 206c may include the third pickup input sub-band signal 214c.

[0147] In particular implementations of the method 400, the first primary gain stage input signal 210a may include the first primary microphone input sub-band signal 216a.

[0148] In certain implementations of the method 400, the second primary gain stage input signal 210b may include the second primary microphone input sub-band signal 216b.

[0149] In particular implementations of the method 400, the third primary gain stage input signal 210c may include the third primary microphone input sub-band signal 216c.

[0150] Certain implementations of the method 400 may further comprise, at block 433, by way of a secondary summer 134, producing a secondary summed output signal 228 based on adding together the first secondary gain stage output signal 226a, the second secondary gain stage output signal 226b, and the third secondary gain stage output signal 226c.

[0151] Certain implementations of the method 400 may further comprise, at block 424, by way of a primary signal conditioner 138, conditioning the primary summed output signal 218 and thereby producing a primary conditioned output signal 220.

[0152] Certain implementations of the method 400 may further comprise, at block 434, by way of a secondary signal conditioner 140, conditioning the secondary summed output signal 228 and thereby producing a secondary conditioned output signal 230.

[0153] Certain implementations of the method 400 may further comprise, at block 435,by way of a primary-secondary summer 136, producing a combined processed output signal 232 based on adding together the primary conditioned output signal 220 and the secondary conditioned output signal 230.

[0154] Certain implementations of the method 400 may further comprise, at block 436, by way of a mixer 142, producing a mixed audio output signal 234 based on the pickup input signal 200 and the combined processed output signal 232.

[0155] In particular implementations of the method 400, the pickup 114 may comprise a piezoelectric sensor.

[0156] In certain implementations of the method 400, the pickup 114 may comprise an accelerometer.

[0157] In particular implementations of the method 400, the pickup 114 may comprise an optical sensor.

[0158] In certain implementations of the method 400, the pickup 114 may comprise a MEMS device.

[0159] In particular implementations of the method 400, the pickup 114 may be mounted to an internal surface 152 of the acoustic instrument 102.

[0160] In certain implementations of the method 400, the pickup 114 may be mounted under a saddle 103 of the acoustic instrument 102.

[0161] In particular implementations of the method 400, the microphone 116 may be mounted within the acoustic instrument 102.

[0162] In certain implementations of the method 400, the pickup input signal 200 may be configured to control at least a 100 hertz wide portion of a frequency spectrum of themicrophone input signal 202.

[0163] In particular implementations of the method 400, the microphone 116 may comprise an electret microphone.

[0164] In certain implementations of the method 400, the pickup input signal 200 may include a minimum threshold level below which no gain control signal 208a, 208b, or 208c is output.

[0165] In particular implementations of the method 400, the audio signal amplification device 104 may be disposed within the acoustic instrument 102.

[0166] In certain implementations of the method 400, the audio signal amplification device 104 and the microphone 116 may be mounted on a printed circuit board disposed within the acoustic instrument 102.

[0167] In particular implementations of the method 400, the audio signal amplification device 104 may be disposed externally to the acoustic instrument 102.

[0168] In certain implementations of the method 400, the acoustic instrument 102 may comprise a guitar.

[0169] In particular implementations of the method 400, the method 400 may be performed at least in part by way of one or more software programs running on one or more computer processors.

[0170] In certain implementations of the method 400, all steps of the method 400 may be performed by way of one or more software programs running on one or more computer processors.

[0171] FIG. 1 illustrates one non-limiting implementation of the system 100 in accordance with the present disclosure. The operational principles of certain implementations of the system 100, device 104, and associated acoustic instrument amplification methods are based on the observation that accurately capturing the complete frequency response and harmonic content of an acoustic instrument necessitates the use of a microphone. However, to address the commonly encountered limitations associated with microphones, such as feedback, noise, and resonance, particular implementations of the present disclosure incorporate a second sensor. In some such implementations of the system 100, this second sensor is not constrained by the requirements for acoustic fidelity and can thus be optimized for other performance parameters.

[0172] Referring to FIG. 1, particular implementations of the system 100 comprise a piezoelectric pickup input 106 and microphone input 108, wherein the pickup input is connected to an envelope follower 120a (e.g., envelope follower analyzer circuit) and the microphone input is connected to a gain stage block 112a so that the gain stage block is controlled by the envelope follower analyzer control signal. In such implementations of the system 100, the output of the gain stage block is then connected to 112 output.

[0173] In particular implementations of the system 100, a piezoelectric pickup is utilized as the vibration sensor, as it is widely adopted as an industry standard. In other implementations of the system 100, the vibration sensor may include an accelerometer, an optical sensor, or other suitable devices capable of capturing vibrations or related parameters. In certain implementations of the system 100, the vibration sensor is a string vibration sensor, such as, for example, a magnetic pickup for a steel stringed instrument.

[0174] One potentially key innovation of this invention may lie in the discovery that by employing the output of the second sensor to modulate the amplitude of the microphone signal, the frequency spectrum captured by the microphone remains unaffected. Notably, the dynamic response may be only marginally altered, as the perceived dynamics — interpreted as variations in loudness — are largely influenced by harmonic content rather than absolute signal amplitude.

[0175] In particular implementations of the system 100, device 104 and associated methods disclosed herein, feedback, along with unwanted noise and resonance, is effectively eliminated from the microphone in a straightforward manner. Since the microphone output is amplitude-modulated by the envelope of the vibration sensor, when a feedback event occurs in the microphone, it is unlikely to be mirrored in the vibration sensor. As a result, the microphone output may be near zero during the feedback event, effectively blocking the feedback from the outset.

[0176] Referring to FIGS. 1 and 3A-3B, certain implementations of the system 100 disclosed herein may include or employ a device 104 configured to implement the associated amplifications methods disclosed herein. For example, this device may include at least one pickup input 106 and at least one microphone input 108. The microphone input signal may be processed through a gain block (e g., 122a, 122b, 122c or 124a, 124b, 124c), where the gain is adjustable, prior to output at the output stage 112. Additionally, the device may feature an envelope follower processing block (e.g., 120a, 120b, 120c), which analyzes the signal from the pickup input. The output of the envelope follower is employed to control the gain of the microphone signal.

[0177] Referring to FIG. 2, in certain implementations of the system 100, a signal 301 is analyzed and the amplitude envelope 302 of the input signal is generated as output. FIG. 2 depicts a basic configuration of the envelope follower in the time domain, wherein the envelope 302 is derived through a combination of signal rectification and filtering of the input signal 301.

[0178] In particular implementations of the system, the envelope follower may be configured to provide adjustable filtering coefficients, including attack, release, and threshold parameters. Such a configuration may enable precise tailoring of the dynamic response and allow the output signal to be reduced to zero when the input from the vibration sensor is low, thereby offering a significant noise reduction benefit.

[0179] FIG 3 A shows yet another example implementation of the system 100, in whichthe envelope follower employs a multi-band filtering approach in the time domain or utilizes a sliding window Fourier transform in the frequency domain. In some such implementations of the system 100, the frequency spectrum is divided into sub-bands (214a, 214b, 214b), with each sub-band analyzed individually. In some such implementations of the system 100, the outputs from the envelope follower corresponding to each sub-band (208a, 208b, 208c) are then used to control the gain of the associated sub-spectrum band (216a, 216b, 216c) of the microphone input signal 202.

[0180] Referring to FIG. 3 A, in particular implementations of the system 100, both the pickup input signal 200 and microphone input signal 202 are first processed by a respective crossover block (130, 126), such that each input signal is split into three different frequency bands (e.g., 214a, 214b, 214c and 216a, 216b, 216c), where a respective envelope follower (120a, 120b, 120c) analyzes each frequency sub band of the pickup input (214a, 214b, 214c) and the output of each controls the corresponding microphone input frequency band gain block (122a, 122b, 122c). In some such implementations of the system 100, the results of the gain blocks are then mixed together with a sum block 132 and it’s further processed by a signal conditioner block 138.

[0181] The multi-band or frequency-domain approach may allow for precise and adaptive control over the microphone gain across the entire frequency spectrum, thereby enhancing the fidelity and robustness of the device.

[0182] In particular implementations of the system 100 and associated acoustic instrument amplification methods, a signal conditioning block may additionally be incorporated prior to the output of the device, providing enhanced control over the audio spectrum of the signal. This block may enable precise adjustments to parameters such as bass, treble, compression, and other common settings, allowing the response to be tailored to the preferences of the musician.

[0183] Referring to FIG 3B, certain implementation of the system 100 incorporate a second microphone and a mixer block 142. This addition may allow musicians to blend andselect any combination of the vibration sensor signal and the processed signals from the microphones. Moreover, this configuration may enable the device to reproduce a classic sound that has been prominently used in many recordings and remains a preferred choice for certain applications.

[0184] In certain implementations of the acoustic instrument amplification system 100 and associated acoustic instrument amplification methods disclosed herein, the discrete functions (shown for example in the individual blocks of FIGS. 1, 3A and 3B) may be performed by corresponding physical components or circuits. Contrastingly, in other implementations of the acoustic instrument amplification system and associated acoustic instrument amplification methods disclosed herein, the discrete functions (shown for example in the blocks of FIGS. 1, 3A and 3B) may be performed in whole or in part by way of one or more software programs (e.g., software plug-ins) running on one or more computer processors. Relatedly, some or all of the various signals described herein may be in the form of analog or digital signals to be used, modified or generated by physical components or circuits (e.g., represented by the individual blocks in FIGS. 1, 3A and 3B), or may be in the form of data to be used, modified or generated by respective software processes (e.g., processes represented by the individual blocks in FIGS. 1, 3 A and 3B).

[0185] Referring to FIG. 4A, certain implementations of the system 100 comprise an under-saddle piezoelectric transducer 114 mounted on an internal surface 152 of an acoustic instrument 102. The transducer 114 may be operatively connected to a printed circuit board 154. A microphone 116 may be disposed on the printed circuit board. The processed output may be electrically coupled to an output connector 150.

[0186] Referring to FIG. 4B, particular implementations of the system 100 include an under saddle piezoelectric transducer 114 mounted on an internal surface 152 of an acoustic instrument 102, wherein the transducer is electrically coupled to an output connector 144. The output connector may be further electrically coupled, either via a wired or wireless connection, to an external processing device 154 (which may be or include the audio signal amplification device 104). Additionally, at least one external microphone (116, 118) may be electricallycoupled to the external processing device 154 through a wired or wireless connection. The processed output (e.g., 212a, 220, or 234) according to this example configuration may then be electrically coupled to an output connector 105.

[0187] Advantages of certain implementations of the system and method disclosed herein may include one or more of the following: (a) the system does not require a specially developed microphone; the only criterion for selecting a microphone is its inherent sonic performance, which eliminates concerns about feedback or noise issues, making the system highly economical; (b) there is no need for a specially developed or compromised vibration sensor, as its output is solely used to modulate the amplitude of the microphone signal; this design allows for easy retrofitting using vibration sensors that are already commonly integrated into instruments; and (c) the system can be seamlessly implemented in both analog and digital domains; in the digital domain, it requires minimal computational power, making it suitable for integration with simple, low-power and low-cost digital signal processors.

[0188] In certain implementations of a device for processing the output of at least two sensors: (a) at least one sensor is attached to an acoustic instrument; (b) at least one sensor is configured to generate a signal indicative of the vibration generated on a surface of the instrument; (c) at least one sensor is a microphone; and (d) the vibration sensor amplitude envelope output is configured to control the amplitude of at least a microphone sensor.

[0189] In particular implementations of the device the vibration sensor output is configured to control at least a lOOhz wide portion of the frequency spectrum of the microphone sensor.

[0190] In certain implementations of the device the vibration sensor output includes a minimum threshold level.

[0191] In particular implementations of the device the vibration sensor is a piezoelectricsensor.

[0192] In certain implementations of the vibration sensor is an accelerometer.

[0193] In particular implementations of the device the vibration sensor is an optical sensor.

[0194] In certain implementations of the device the microphone is a MEMS device.

[0195] In particular implementations of the device the microphone is an electret microphone.

[0196] In certain implementations of a method for processing the output of at least two sensor: (a) at least one sensor is attached to an acoustic instrument; (b) at least one sensor is configured to generate a signal indicative of the vibration generated on a surface of the instrument;(c) at least one sensor is a microphone; and (d) at least a lOOhz wide portion of the vibration sensor amplitude envelope output is configured to control at least a lOOhz wide portion of the amplitude of a microphone sensor.

[0197] In particular implementations of the method the vibration sensor amplitude envelope is derived using a filter-bank in time domain.

[0198] In certain implementations of the method the vibration sensor amplitude envelope is derived in frequency domain.

[0199] The following listing matches certain terminology used within this disclosure with corresponding reference numbers used in the non-limiting examples illustrated in the several figures.100 amplification system102 acoustic instrument103 saddle (of acoustic instrument)104 audio signal amplification device105 output connector106 pickup input terminal108 primary microphone input terminal110 secondary microphone input terminal112 device output terminal (e.g., with output connector)114 pickup (e.g., piezoelectric transducer, optical sensor, accelerometer or MEMS device) 116 microphone (e.g., primary microphone)118 microphone (e.g., secondary microphone)120a first envelope follower (e.g., as a hardware component / circuit or a software m odul e / functi on)120b second envelope follower (e.g., as a hardware component / circuit or a software module / function)120c third envelope follower (e.g., as a hardware component / circuit or a software modul e / functi on)122a first primary microphone gain stage (i.e., first primary gain stage, e.g., as a hardware component / circuit or a software module / function)122b second primary microphone gain stage (i.e., second primary gain stage, e.g., as a hardware component / circuit or a software module / function)122c third primary microphone gain stage (i.e., third primary gain stage, e.g., as a hardware component / circuit or a software module / function)124a first secondary microphone gain stage (i.e., first secondary gain stage, e.g., as a hardware component / circuit or a software module / function)124b second secondary microphone gain stage (i.e., second secondary gain stage, e.g., as a hardware component / circuit or a software module / function)124c third secondary microphone gain stage (i.e., third secondary gain stage, e.g., as a hardware component / circuit or a software module / function)126 primary audio crossover (e.g., as a hardware component / circuit or a software module / function)128 secondary audio crossover (e.g., as a hardware component / circuit or a softwarem odul e / functi on)130 pickup crossover (e.g., as a hardware component / circuit or a software module / function) 132 primary summer (e.g., a summing amplifier; e.g., as a hardware component / circuit or a software module / function)134 secondary summer (e.g., a summing amplifier; e.g., as a hardware component / circuit or a software module / function)136 primary-secondary summer (e.g., a summing amplifier; e.g., as a hardware component / circuit or a software module / function)138 primary signal conditioner (e.g., as a hardware component / circuit or a software modul e / functi on)140 secondary signal conditioner (e.g., as a hardware component / circuit or a software m odul e / functi on)142 mixer (e.g., audio mixer; e.g., as a hardware component / circuit or a software module / function)144 pickup output connector146 primary microphone input connector148 secondary microphone input connector150 output connector152 internal surface (of acoustic instrument)154 device (e g., processing device within or external to the acoustic instrument)200 pickup input signal202 microphone input signal (e.g., primary microphone input signal from primary microphone)204 microphone input signal (e.g., secondary microphone input signal from secondary microphone)206a first follower input signal206b second follower input signal206c third follower input signal208a first gain control signal208b second gain control signal208c third gain control signala first primary gain stage input signalb second primary gain stage input signalc third primary gain stage input signala first primary gain stage output signalb second primary gain stage output signalc third primary gain stage output signala first pickup input sub-band signalb second pickup input sub-band signalc third pickup input sub-band signala first primary microphone input sub-band signalb second primary microphone input sub-band signalc third primary microphone input sub-band signalprimary summed output signalprimary conditioned output signala first secondary microphone input sub-band signalb second secondary microphone input sub-band signalc third secondary microphone input sub-band signala first secondary gain stage input signalb second secondary gain stage input signalc third secondary gain stage input signala first secondary gain stage output signalb second secondary gain stage output signalc third secondary gain stage output signalsecondary summed output signalsecondary conditioned output signalcombined processed output signalmixed audio output signalsignalamplitude envelopeacoustic instrument amplification method (i.e., method)-436 plurality of steps for an acoustic instrument amplification method

[0200] While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

Claims

WHAT TS CLAIMED TS:

1. An acoustic instrument amplification system comprising:an audio signal amplification device includinga pickup input terminal configured to be in pickup input signal receiving communication with a pickup mounted to an acoustic instrument;a primary microphone input terminal configured to be in primary microphone input signal receiving communication with a primary microphone;a first envelope follower configured to receive a first follower input signal and to output a first gain control signal based on amplitude of the first follower input signal; anda first primary gain stage configured to receive a first primary gain stage input signal and to output a first primary gain stage output signal based on the first primary gain stage input signal and based on the first gain control signal;whereinthe pickup is configured to sense vibration of the acoustic instrument to which it is mounted independently of airborne sound;the first follower input signal includes at least a portion of the pickup input signal;andthe first primary gain stage input signal includes at least a portion of the primary microphone input signal.

2. The acoustic instrument amplification system of claim 1, wherein the audio signal amplification device is configured so that the first follower input signal includes the entire pickup input signal.

3. The acoustic instrument amplification system of claim 1, wherein the audio signal amplification device is configured so that the first primary gain stage input signal includes the entire primary microphone input signal.

4. The acoustic instrument amplification system of claim 1, whereinthe audio signal amplification device further includesa pickup crossover configured to split the pickup input signal into at least a first pickup input sub-band signal and a second pickup input sub-band signal;a primary audio crossover configured to split the primary microphone input signal into at least a first primary microphone input sub-band signal and a second primary microphone input sub-band signal;a second envelope follower configured to receive a second follower input signal and to output a second gain control signal based on amplitude of the second follower input signal; anda second primary gain stage configured to receive a second primary gain stage input signal and to output a second primary gain stage output signal based on the second primary gain stage input signal and based on the second gain control signal;the first follower input signal includes the first pickup input sub-band signal;the second follower input signal includes the second pickup input sub-band signal; the first primary gain stage input signal includes the first primary microphone input subband signal; andthe second primary gain stage input signal includes the second primary microphone input sub-band signal.

5. The acoustic instrument amplification system of claim 4, whereinthe audio signal amplification device further includes a primary summer configured to produce a primary summed output signal based on adding together the first primary gain stage output signal, and the second primary gain stage output signal.

6. The acoustic instrument amplification system of claim 5, whereinthe audio signal amplification device further includes a primary signal conditioner configured to condition the primary summed output signal and thereby produce a primary conditioned output signal.

7. The acoustic instrument amplification system of claim 1, whereinthe audio signal amplification device further includesa pickup crossover configured to split the pickup input signal into at least a first pickup input sub-band signal, a second pickup input sub-band signal, and a third pickup input sub-band signal;a primary audio crossover configured to split the primary microphone input signal into at least a first primary microphone input sub-band signal, a second primary microphone input sub-band signal, and a third primary microphone input subband signal;a second envelope follower configured to receive a second follower input signal and to output a second gain control signal based on amplitude of the second follower input signal;a second primary gain stage configured to receive a second primary gain stage input signal and to output a second primary gain stage output signal based on the second primary gain stage input signal and based on the first gain control signal; a third envelope follower configured to receive a third follower input signal and to output a third gain control signal based on amplitude of the third follower input signal; anda third primary gain stage configured to receive a third primary gain stage input signal and to output a third primary gain stage output signal based on the third primary gain stage input signal and based on the third gain control signal;the first follower input signal includes the first pickup input sub-band signal;the second follower input signal includes the second pickup input sub-band signal; the third follower input signal includes the third pickup input sub-band signal;the first primary gain stage input signal includes the first primary microphone input subband signal;the second primary gain stage input signal includes the second primary microphone input sub-band signal; andthe third primary gain stage input signal includes the third primary microphone input subband signal.

8. The acoustic instrument amplification system of claim 7, whereinthe audio signal amplification device further includes a primary summer configured to produce a primary summed output signal based on adding together the first primary gain stage output signal, the second primary gain stage output signal, and the third primary gain stage output signal.

9. The acoustic instrument amplification system of claim 8, whereinthe audio signal amplification device further includesa secondary microphone input terminal configured to be in secondary microphone input signal receiving communication with a secondary microphone; a secondary audio crossover configured to split the secondary microphone input signal into at least a first secondary microphone input sub-band signal, a second secondary input sub-band signal, and a third secondary microphone input subband signal;a first secondary gain stage configured to receive a first secondary gain stage input signal and to output a first secondary gain stage output signal based on the first secondary gain stage input signal and based on the first gain control signal; a second secondary gain stage configured to receive a second secondary gain stage input signal and to output a second secondary gain stage output signal based on the second secondary gain stage input signal and based on the second gain control signal; anda third secondary gain stage configured to receive a third secondary gain stage input signal and to output a third secondary gain stage output signal based on the third secondary gain stage input signal and based on the third gain control signal;r the first secondary gain stage input signal includes the first secondary microphone input sub-band signal;the second secondary gain stage input signal includes the second secondary microphone input sub-band signal; andthe third secondary gain stage input signal includes the third secondary microphone input sub-band signal.

10. The acoustic instrument amplification system of claim 9, whereinthe audio signal amplification device further includes a secondary summer configured to produce a secondary summed output signal based on adding together the first secondary gain stage output signal, the second secondary gain stage output signal, and the third secondary gain stage output signal.

11. The acoustic instrument amplification system of claim 10, whereinthe audio signal amplification device further includesa primary signal conditioner configured to condition the primary summed output signal and thereby produce a primary conditioned output signal;a secondary signal conditioner configured to condition the secondary summed output signal and thereby produce a secondary conditioned output signal; and a primary-secondary summer configured to produce a combined processed output signal based on adding together the primary conditioned output signal and the secondary conditioned output signal.

12. The acoustic instrument amplification system of claim 11, whereinthe audio signal amplification device further includes a mixer configured to produce a mixed audio output signal based on the pickup input signal and the combined processed output signal.

13. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is a piezoelectric sensor.

14. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is an accelerometer.

15. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is an optical sensor.

16. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is a MEMS device.

17. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is mounted to an internal surface of the acoustic instrument.

18. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup is mounted under a saddle of the acoustic instrument.

19. The acoustic instrument amplification system of any one of claims 1-12, wherein the primary microphone is mounted within the acoustic instrument.

20. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup input signal is configured to control at least a lOOhz wide portion of the frequency spectrum of the primary microphone input signal.

21. The acoustic instrument amplification system of any one of claims 1-12, wherein the primary microphone is an electret microphone.

22. The acoustic instrument amplification system of any one of claims 1-12, wherein the pickup input signal includes a minimum threshold level below which no gain control signals will be output.

23. The acoustic instrument amplification system of any one of claims 1-12, wherein the audio signal amplification device is disposed within the acoustic instrument.

24. The acoustic instrument amplification system of any one of claims 1-12, wherein the audio signal amplification device and the primary microphone are mounted on a printed circuit board disposed within the acoustic instrument.

25. The acoustic instrument amplification system of any one of claims 1-12, wherein the audio signal amplification device is disposed externally to the acoustic instrument.

26. The acoustic instrument amplification system of any one of claims 1-12, wherein the acoustic instrument is a guitar.

27. An acoustic instrument amplification method comprising:receiving a pickup input signal from a pickup mounted to an acoustic instrument; receiving a primary microphone input signal from a primary microphone; by way of a first envelope follower, receiving a first follower input signal and outputting a first gain control signal based on amplitude of the first follower input signal; andby way of a first primary gain stage, receiving a first primary gain stage input signal and outputting a first primary gain stage output signal based on the first primary gain stage input signal and based on the first gain control signal;whereinthe pickup is configured to sense vibration of the acoustic instrument to which it is mounted independently of airborne sound;the first follower input signal includes at least a portion of the pickup input signal;andthe first primary gain stage input signal includes at least a portion of the primary microphone input signal.

28. The acoustic instrument amplification method of claim 27, wherein the first follower input signal includes the entire pickup input signal.

29. The acoustic instrument amplification method of claim 27, wherein the first primary gain stage input signal includes the entire primary microphone input signal.

30. The acoustic instrument amplification method of claim 27, further comprising:by way of a pickup crossover, splitting the pickup input signal into at least a first pickup input sub-band signal and a second pickup input sub-band signal;by way of a primary audio crossover, splitting the primary microphone input signal into at least a first primary microphone input sub-band signal and a second primary microphone input sub-band signal;by way of a second envelope follower, receiving a second follower input signal and outputting a second gain control signal based on amplitude of the second follower input signal; andby way of a second primary gain stage, receiving a second primary gain stage input signal and outputting a second primary gain stage output signal based on the second primary gain stage input signal and based on the second gain control signal;whereinthe first follower input signal includes the first pickup input sub-band signal; the second follower input signal includes the second pickup input sub-band signal;the first primary gain stage input signal includes the first primary microphone input sub-band signal; andthe second primary gain stage input signal includes the second primary microphone input sub-band signal.

31. The acoustic instrument amplification method of claim 30, further comprising:by way of a primary summer, producing a primary summed output signal based on adding together the first primary gain stage output signal and the second primary gain stage output signal.

32. The acoustic instrument amplification method of claim 31, further comprising:by way of a primary signal conditioner, conditioning the primary summed output signal thereby producing a primary conditioned output signal.

33. The acoustic instrument amplification method of claim 27, further comprising:by way of a pickup crossover, splitting the pickup input signal into at least a first pickup input sub-band signal, a second pickup input sub-band signal, and a third pickup input sub-band signal;by way of a primary audio crossover, splitting the primary microphone input signal into at least a first primary microphone input sub-band signal, a second primary microphone input sub-band signal, and a third primary microphone input subband signal;by way of a second envelope follower, receiving a second follower input signal outputting a second gain control signal based on amplitude of the second followerinput signal;by way of a second primary gain stage, receiving a second primary gain stage input signal and outputting a second primary gain stage output signal based on the second primary gain stage input signal and based on the first gain control signal; by way of a third envelope follower, receiving a third follower input signal and outputting a third gain control signal based on amplitude of the third follower input signal; andby way of a third primary gain stage, receiving a third primary gain stage input signal and outputting a third primary gain stage output signal based on the third primary gain stage input signal and based on the third gain control signal;whereinthe first follower input signal includes the first pickup input sub-band signal; the second follower input signal includes the second pickup input sub-band signal;the third follower input signal includes the third pickup input sub-band signal; the first primary gain stage input signal includes the first primary microphone input sub-band signal;the second primary gain stage input signal includes the second primary microphone input sub-band signal; andthe third primary gain stage input signal includes the third primary microphone input sub-band signal.

34. The acoustic instrument amplification method of claim 33, further comprising:by way of a primary summer, producing a primary summed output signal based on adding together the first primary gain stage output signal, the second primary gain stage output signal, and the third primary gain stage output signal.

35. The acoustic instrument amplification method of claim 34, further comprising:receiving a secondary microphone input signal from a secondary microphone; by way of a secondary audio crossover, splitting the secondary microphone input signal into at least a first secondary microphone input sub-band signal, a second secondary microphone input sub-band signal, and a third secondary microphoneinput sub-band signal;by way of a first secondary gain stage, receiving a first secondary gain stage input signal and outputting a first secondary gain stage output signal based on the first secondary gain stage input signal and based on the first gain control signal; by way of a second secondary gain stage, receiving a second secondary gain stage input signal and outputting a second secondary gain stage output signal based on the second secondary gain stage input signal and based on the second gain control signal; andby way of a third secondary gain stage, receiving a third secondary gain stage input signal and outputting a third secondary gain stage output signal based on the third secondary gain stage input signal and based on the third gain control signal; whereinthe first secondary gain stage input signal includes the first secondary microphone input sub-band signal;the second secondary gain stage input signal includes the second secondary microphone input sub-band signal; andthe third secondary gain stage input signal includes the third secondary microphone input sub-band signal.

36. The acoustic instrument amplification method of claim 35, further comprising:by way of a secondary summer, producing a secondary summed output signal based on adding together the first secondary gain stage output signal, the second secondary gain stage output signal, and the third secondary gain stage output signal.

37. The acoustic instrument amplification method of claim 36, further comprising:by way of a primary signal conditioner, conditioning the primary summed output signal thereby producing a primary conditioned output signal;by way of a secondary signal conditioner, conditioning the secondary summed output signal thereby producing a secondary conditioned output signal; and by way of a primary-secondary summer, producing a combined processed output signal based on adding together the primary conditioned output signal and the secondary conditioned output signal.

38. The acoustic instrument amplification method of claim 37, further comprising:by way of a mixer, producing a mixed audio output signal based on the pickup input signal and the combined processed output signal.

39. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is a piezoelectric sensor.

40. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is an accelerometer.

41. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is an optical sensor.

42. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is a MEMS device.

43. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is mounted to an internal surface of the acoustic instrument.

44. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup is mounted under a saddle of the acoustic instrument.

45. The acoustic instrument amplification method of any one of claims 27-38, wherein the primary microphone is mounted within the acoustic instrument.

46. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup input signal is configured to control at least a lOOhz wide portion of the frequency spectrum of the primary microphone input signal.

47. The acoustic instrument amplification method of any one of claims 27-38, wherein the primary microphone is an electret microphone.

48. The acoustic instrument amplification method of any one of claims 27-38, wherein the pickup input signal includes a minimum threshold level below which no gain control signals will be output.

49. The acoustic instrument amplification method of any one of claims 27-38, wherein the method is performed at least in part by way of an audio signal amplification device disposed within the acoustic instrument.

50. The acoustic instrument amplification method of any one of claims 27-38, wherein the method is performed at least in part by way of an audio signal amplification device and the primary microphone, wherein the audio signal amplification device and the primary microphone are mounted on a printed circuit board disposed within the acoustic instrument.

51. The acoustic instrument amplification method of any one of claims 27-38, wherein the method is performed at least in part by way of an audio signal amplification device disposed externally to the acoustic instrument.

52. The acoustic instrument amplification method of any one of claims 27-38, wherein the acoustic instrument is a guitar.

53. The acoustic instrument amplification method of any one of claims 27-38, wherein the method is performed at least in part by way of one or more software programs running on one or more computer processors.

54. The acoustic instrument amplification method of any one of claims 27-38, wherein all steps of the method are performed by way of one or more software programs running on one or more computer processors.

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