Methods and systems for reducing an effect of ambient noise within an auditory prosthesis system
An exemplary method of reducing an effect of ambient noise within an auditory prosthesis system includes dividing an audio signal presented to an auditory prosthesis patient into a plurality of analysis channels each containing a frequency domain signal representative of a distinct frequency portion of the audio signal, determining a signal-to-noise ratio and a noise reduction gain parameter based on the signal-to-noise ratio for each of the frequency domain signals, applying noise reduction to the frequency domain signals in accordance with the determined noise reduction gain parameters to generate a noise reduced frequency domain signal corresponding to each of the analysis channels, and generating one or more stimulation parameters based on the noise reduced frequency domain signals and in accordance with at least one of a current steering stimulation strategy and an N-of-M stimulation strategy. Corresponding methods and systems are also disclosed.
1. A method of reducing an effect of ambient noise within an auditory prosthesis system, the method comprising:
dividing, by a sound processing subsystem, an audio signal presented to an auditory prosthesis patient into a plurality of analysis channels each containing a frequency domain signal representative of a distinct frequency portion of the audio signal;
determining, by the sound processing subsystem, a noise reduction gain parameter for each of the frequency domain signals based on a signal-to-noise ratio of each of the frequency domain signals;
applying, by the sound processing subsystem, noise reduction to the frequency domain signals in accordance with the determined noise reduction gain parameters to generate a noise reduced frequency domain signal corresponding to each of the analysis channels; and
generating, by the sound processing subsystem, one or more stimulation parameters based on the noise reduced frequency domain signals and in accordance with at least one of a current steering stimulation strategy and an N-of-M stimulation strategy.
2. The method of claim 1 , further comprising generating and applying, by a stimulation subsystem communicatively coupled to the sound processing subsystem, electrical stimulation to at least one stimulation site associated with an auditory pathway of a patient via one or more of a plurality of stimulation channels in accordance with the one or more stimulation parameters.
3. The method of claim 2 , wherein a total number of the plurality of stimulation channels is greater than or equal to a total number of the analysis channels.
4. The method of claim 1 , further comprising dynamically adjusting, by the sound processing subsystem, an amount of the noise reduction applied to the frequency domain signals in accordance with a type of the audio signal.
5. The method of claim 4 , wherein when the audio signal comprises music, the dynamically adjusting comprises reducing the amount of the noise reduction applied to the frequency domain signals.
6. The method of claim 1 , wherein the determining of the noise reduction gain parameter for each of the frequency domain signals comprises:
determining the signal-to-noise ratio for each of the frequency domain signals.
7. The method of claim 6 , wherein the if the signal-to-noise ratio of a frequency domain signal included within the frequency domain signals is greater than a predetermined maximum threshold, the determining of the noise reduction gain parameter corresponding to the frequency domain signal comprises assigning a value of one to the noise reduction gain parameter corresponding to the frequency domain signal.
8. The method of claim 7 , further comprising independently setting the predetermined maximum threshold.
9. The method of claim 6 , wherein the if the signal-to-noise ratio of a frequency domain signal included within the frequency domain signals is less than a predetermined minimum threshold, the determining of the noise reduction gain parameter corresponding to the frequency domain signal comprises assigning a value of zero to the noise reduction gain parameter corresponding to the frequency domain signal.
10. The method of claim 1 , wherein the generating of the one or more stimulation parameters is in accordance with the current steering stimulation strategy, and wherein the method further comprises generating, by the sound processing subsystem, a focusing factor used to narrow one or more excitation fields produced by the current steering stimulation strategy.
11. The method of claim 1 , wherein the generating of the one or more stimulation parameters is in accordance with the N-of-M stimulation strategy, and wherein the method further comprises selecting, by the sound processing subsystem, N stimulation channels to which electrical stimulation is to be applied in accordance with a selection heuristic.
12. A system comprising:
a frequency analysis facility configured to a divide an audio signal presented to an auditory prosthesis patient into a plurality of analysis channels each containing a frequency domain signal representative of a distinct frequency portion of the audio signal;
a noise reduction facility communicatively coupled to the frequency analysis facility and configured to
determine a noise reduction gain parameter for each of the frequency domain signals based on a signal-to-noise ratio of each of the frequency domain signals, and
apply noise reduction to the frequency domain signals in accordance with the determined noise reduction gain parameters to generate a noise reduced frequency domain signal corresponding to each of the analysis channels; and
a stimulation strategy facility communicatively coupled to the noise reduction facility and configured to generate one or more stimulation parameters based on the noise reduced frequency domain signals and in accordance with at least one of a current steering stimulation strategy and an N-of-M stimulation strategy.
13. The system of claim 12 , further comprising:
a current generation facility configured to generate electrical stimulation in accordance with the one or more stimulation parameters; and
a stimulation facility configured to apply the electrical stimulation to at least one stimulation site associated with an auditory pathway of a patient via one or more of a plurality of stimulation channels in accordance with the one or more stimulation parameters.
14. The system of claim 13 , wherein a total number of the plurality of stimulation channels is greater than or equal to a total number of the analysis channels.
15. The system of claim 12 , wherein the noise reduction facility is further configured to dynamically adjust an amount of the noise reduction applied to the frequency domain signals in accordance with a type of the audio signal.
16. The system of claim 15 , wherein when the audio signal comprises music, the noise reduction facility is configured to dynamically adjust the amount of noise reduction applied to the frequency domain signals by reducing the amount of the noise reduction applied to the frequency domain signals.
17. The system of claim 12 , wherein if a signal-to-noise ratio of a frequency domain signal included within the frequency domain signals is greater than a predetermined maximum threshold, the noise reduction facility is further configured to assign a value of one to a noise reduction gain parameter corresponding to the frequency domain signal.
18. The system of claim 12 , wherein if a signal-to-noise ratio of a frequency domain signal included within the frequency domain signals is less than a predetermined minimum threshold, the noise reduction facility is further configured to assign a value of zero to a noise reduction gain parameter corresponding to the frequency domain signal.
19. The system of claim 12 , wherein the generating of the one or more stimulation parameters is in accordance with the current steering stimulation strategy, and wherein the stimulation strategy facility is further configured to generate a focusing factor used to narrow one or more excitation fields produced by the current steering stimulation strategy.
20. A system comprising:
a sound processor configured to
divide an audio signal presented to an auditory prosthesis patient into a plurality of analysis channels each containing a frequency domain signal representative of a distinct frequency portion of the audio signal,
determine a signal-to-noise ratio and a noise reduction gain parameter based on the signal-to-noise ratio for each of the frequency domain signals, and
apply noise reduction to the frequency domain signals in accordance with the determined noise reduction gain parameters to generate a noise reduced frequency domain signal corresponding to each of the analysis channels; and
an implantable cochlear stimulator communicatively coupled to the sound processor and configured to
generate electrical stimulation based on the noise reduced frequency domain signals, and
apply the electrical stimulation to at least one stimulation site within a cochlea of a patient via a plurality of stimulation channels in accordance with at least one of a current steering stimulation strategy and an N-of-M stimulation strategy.