Signal processor with side-tone noise reduction for a headset
AssigneeGn Audio A/S
InventorsAllan Mejlgren Von Bulow, Christoffer Bovbjerg
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Abstract
A signal processor (105) for a headset (101) configured with a microphone terminal (106) for receiving a microphone signal, a loudspeaker terminal (107) for outputting a loudspeaker signal, and a far-end terminal (108) for communicating an inbound signal and an outbound signal with a far-end; comprising: a side-tone path (110) configured to generate a side-tone signal from the microphone signal via a controllable side-tone filter; wherein a side-tone filter controller (114) receives the microphone signal and computes a first noise estimate with a signal-to-noise level of the microphone signal at respective frequency bands and based thereon controls the side-tone filter (111) to improve or optimize a signal-to-noise ratio.
Claims19
A signal processor for a headset configured with a microphone terminal for receiving a microphone signal, a loudspeaker terminal for outputting a loudspeaker signal, and a far-end terminal for communicating an inbound signal and an outbound signal with a far-end;
- comprising:
- an outbound path from the microphone terminal to the far-end terminal;
- a side-tone path configured to generate a side-tone signal from the microphone signal via a side-tone filter,
- an inbound path from the far-end terminal to the loudspeaker terminal and comprising a combiner configured to combine the side-tone signal and the inbound signal to generate the loudspeaker signal;
- and
- a side-tone filter controller that receives the microphone signal and computes a first noise estimate with a signal-to-noise level of the microphone signal at respective frequency bands and based thereon controls the side-tone filter to improve a signal-to-noise ratio of the side-tone signal;
- wherein the side-tone filter in the side-tone path comprises multiple filter stages that are individually controlled based on the first noise estimate;
- and
- wherein the multiple filter stages are configured from a group consisting of:
- multiple peak filters and a high-shelf filter;
- and wherein the side-tone filter controller executes an iterative process of:
- determining parameters for a filter stage based on the first noise estimate;
- computing a frequency domain gain estimate of the frequency domain gain transfer function for a filter stage;
- computing a second noise estimate by subtracting the frequency domain gain estimate from the first noise estimate;
- updating the first noise estimate to be in accordance with the second noise estimate;
- wherein the filter stages are controlled via coefficients computed from the parameters for a respective filter stage computed over iterations of the iterative process;
- and
- wherein determining parameters for a filter stage comprises fitting a filter that has a largest possible gain-bandwidth product while optimizing the signal-to-noise ratio in an audio band of interest.
A signal processing method for generating a side-tone in a headset, comprising:
- generating a side-tone signal via a side-tone filter and from a microphone signal picked up via a microphone of the headset,
- combining the side-tone signal and an inbound signal to the headset to generate a loudspeaker signal for a loudspeaker of the headset;
- computing a first noise estimate of the microphone signal at respective frequency bands and based thereon controlling the side-tone filter to improve a signal-to-noise ratio of the side-tone signal;
- wherein the side-tone filter comprises multiple filter stages that are individually controlled based on the first noise estimate;
- and
- wherein the multiple filter stages are configured from a group consisting of:
- multiple peak filters and a high-shelf filter.
A signal processor for a headset configured with a microphone terminal for receiving a microphone signal, a loudspeaker terminal for outputting a loudspeaker signal, and a far-end terminal for communicating an inbound signal and an outbound signal with a far-end;
- comprising:
- an outbound path from the microphone terminal to the far-end terminal;
- a side-tone path configured to generate a side-tone signal from the microphone signal via a side-tone filter,
- an inbound path from the far-end terminal to the loudspeaker terminal and comprising a combiner configured to combine the side-tone signal and the inbound signal to generate the loudspeaker signal;
- and
- a side-tone filter controller that receives the microphone signal and computes a first noise estimate with a signal-to-noise level of the microphone signal at respective frequency bands and based thereon controls the side-tone filter to improve a signal-to-noise ratio of the side-tone signal;
- wherein the side-tone filter in the side-tone path comprises multiple filter stages that are individually controlled based on the first noise estimate;
- and
- wherein the multiple filter stages are configured from a group consisting of:
- multiple peak filters and a high-shelf filter.
Dependencies are inferred from the claim text.