Wearable hearing assist device with sound pressure level shifting
Various implementations include hearing assist devices and systems for processing audio signals. In particular implementations, a process includes receiving an input signal via a microphone; performing a sound pressure level (SPL) shift that decreases a gain of the input signal to generate a gain reduced audio signal; amplifying the gain reduced audio signal using dynamic range compression to generate an amplified audio signal; generating a noise reduced amplified signal using active noise reduction that simultaneously processes the input signal; and outputting the noise reduced amplified signal to an electrodynamic transducer.
1 . A method for processing signals in a hearing assistance device, the method comprising:
receiving an input signal via a microphone;
performing a sound pressure level (SPL) shift that decreases a gain of the input signal to generate a gain reduced audio signal;
amplifying the gain reduced audio signal using dynamic range compression to generate an amplified audio signal;
generating a noise reduced signal using active noise reduction that simultaneously processes the input signal; and
combining the noise reduced signal with the amplified audio signal.
2 . The method of claim 1 , wherein an amount of the SPL shift is one of: (1) selectable via an input control or (2) calculated using one of a plurality of selectable functions that determines the amount of SPL shift based on an environmental assessment.
3 . The method of claim 1 , further comprising:
receiving an environmental assessment with a sensor; and
determining an amount of the SPL shift based on the environmental assessment.
4 . The method of claim 3 , wherein the sensor comprises at least one of a separate microphone, a vibration detector, a wind detector, and a noise level detector, wherein the environmental assessment comprises a detected loudness, and wherein the amount of SPL shift is based on a function that varies the amount of SPL shift as the detected loudness increases.
5 . The method of claim 4 , wherein the function is determined using a machine learning model trained on a user behavior.
6 . The method of claim 1 , wherein the dynamic range compression is implemented with a wide dynamic range compression (WDRC) amplifier.
7 . The method of claim 1 , wherein the amplified audio signal has an increased spectral tilt relative to the input signal appropriate for a hearing loss of a user.
8 . A hearing assistance device, comprising: a microphone;
an electrodynamic
transducer; a
memory; and
a processor configured to execute instructions from the memory to process audio signals for the hearing assistance device, wherein the instructions cause the processor to:
receive an input signal via a microphone;
perform a sound pressure level (SPL) shift that decreases a gain of the input signal to generate a gain reduced audio signal;
amplify the gain reduced audio signal using dynamic range compression to generate an amplified audio signal;
generate a noise reduced signal using active noise reduction that simultaneously processes the input signal; and
combine the noise reduced signal with the amplified audio signal and outputting a combined signal to the electrodynamic transducer.
9 . The device of claim 8 , further comprising an input control configured to select an amount of SPL shift.
10 . The device of claim 8 , further comprising a sensor that receives an environmental assessment, wherein the environmental assessment determines an amount of the SPL shift.
11 . The device of claim 10 , wherein the sensor comprises at least one of a separate microphone, a vibration detector, a wind detector, and a noise level detector, wherein the environmental assessment comprises a detected loudness, and wherein the amount of SPL shift is based on one of: i) a function that varies the amount of SPL shift as the detected loudness increases, or ii) one of a plurality of selectable functions that depend on an environmental assessment.
12 . The device of claim 11 , wherein the function is determined using a machine learning model trained on a user behavior.
13 . The device of claim 8 , wherein the dynamic range compression is implemented with a wide dynamic range compression (WDRC) amplifier.
14 . The device of claim 8 , wherein the SPL shift is implemented according to a process that comprises:
using a feedforward ANR filter to process the input signal to produce a noise cancellation signal that is opposite in phase and smaller in magnitude than the input signal; and
summing the noise cancellation signal with the input signal to generate the gain reduced audio signal.
15 . A method for processing signals in a hearing assistance device, the method comprising:
receiving an input signal via a microphone;
performing a sound pressure level (SPL) shift with a broadband gain reduction that decreases a gain of the input signal to generate a gain reduced audio signal;
amplifying the gain reduced audio signal using dynamic range compression to generate an amplified audio signal;
generating a noise reduced signal using active noise reduction that simultaneously processes the input signal; and
combining the noise reduced signal with the amplified audio signal.
16 . The method of claim 15 , wherein the gain reduced audio signal is directly amplified using dynamic range compression, wherein the dynamic range compression is implemented with a wide dynamic range compression (WDRC) amplifier.
17 . The method of claim 1 , wherein the SPL shift includes a broadband gain reduction.
18 . The method of claim 6 , wherein the gain reduced audio signal is fed directly to the WDRC amplifier.
19 . The device of claim 8 , wherein the SPL shift includes a broadband gain reduction.
20 . The device of claim 13 , wherein the gain reduced audio signal is fed directly to the WDRC amplifier.