Adaptive suppression for removing nuisance audio

An audio capture system for suppressing noise due to mechanical disturbances, the system including:

• a first input port for receiving an input audio signal from a microphone;
• a second input port for receiving an input reference signal from a sensor other than the microphone, wherein the input reference signal is separate from the input audio signal;
• and
• a processor configured for:
• transforming the input audio signal into the frequency domain;
• processing the input reference signal to generate a control signal for identifying a noise event;
• in response to the control signal identifying a noise event, estimating a contribution of the noise event to the input audio signal;
• based on the estimated contribution of the noise event, selectively modifying the input audio signal to generate an output audio signal in which the noise arising from the noise event is at least partially suppressed,
• wherein processing the input reference signal includes transforming the input reference signal into the frequency domain;
• wherein transforming the reference signal includes iteratively transforming the reference signal over predetermined time windows to calculate respective temporally evolving reference power spectra indicative of the reference signal, each reference power spectrum including reference power values separated into a plurality of frequency bins;
• wherein transforming the input audio signal includes iteratively transforming the input audio signal into the frequency domain over the predetermined time windows to calculate respective temporally evolving signal power spectra indicative of the input audio signal, each signal power spectrum including signal power values separated into a like plurality of frequency bins to the reference power spectra;
• and
• wherein estimating the contribution of the noise event to the input audio signal involves applying an adaptive filter in the frequency domain to the reference power spectra and determining parameters of the adaptive filter by comparing the signal power spectra and the reference power spectra over a predetermined period of time, wherein the parameters of the adaptive filter are based on a difference between the reference power spectra after applying the adaptive filter and the signal power spectra.