Keyboard typing detection and suppression
AssigneeGoogle Inc.
InventorsJens Enzo Nyby Christensen, Simon J. Godsill, Jan Skoglund
Life of this patent
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Abstract
Provided are methods and systems for detecting the presence of a transient noise event in an audio stream using primarily or exclusively the incoming audio data. Such an approach offers improved temporal resolution and is computationally efficient. The methods and systems presented utilize some time-frequency representation of an audio signal as the basis in a predictive model in an attempt to find outlying transient noise events and interpret the true detection state as a Hidden Markov Model (HMM) to model temporal and frequency cohesion common amongst transient noise events.
Claims20
A method performed by a teleconference computing device for suppressing transient noise in an audio signal, the method comprising:
- extracting one or more voiced parts from an audio signal input from an audio capture device to yield a residual part of the audio signal;
- decomposing the residual part of the signal into a sparse set of coefficients corresponding to noise pulses in the residual part of the signal;
- modeling each of the coefficients as a switched noise pulse combined with additive noise;
- estimating initial probabilities of detection states for each of the modeled coefficients;
- calculating transition probabilities between each of the detection states;
- determining a probable detection state for each of the coefficients based on the initial probabilities of the detection states for each of the coefficients, the calculated transition probabilities between each of the detection states, and observation probabilities determined from observed data associated with the noise pulses;
- filtering out transient noise from the residual part of the signal based on the probable detection states determined for the coefficients;
- and
- combining the filtered residual part of the signal with the one or more extracted voiced parts of the signal,
- wherein the transient noise is at least one of feedback noise, fan noise, and button-clicking noise due to mechanical connection between the audio capture device and a keyboard or trackpad of the teleconferencing computing device.
A teleconferencing computing system for suppressing transient noise in an audio signal, the system comprising:
- at least one processor;
- and
- a non-transitory computer-readable medium coupled to the at least one processor having instructions stored thereon that, when executed by the at least one processor, causes the at least one processor to:
- extract one or more voiced parts from an audio signal input from an audio capture device to yield a residual part of the audio signal;
- decompose the residual part of the signal into a sparse set of coefficients corresponding to noise pulses in the residual part of the signal;
- model each of the coefficients as a switched noise pulse combined with additive noise;
- estimate initial probabilities of detection states for each of the modeled coefficients;
- calculate transition probabilities between each of the detection states;
- determine a probable detection state for each of the coefficients based on the initial probabilities of the detection states for each of the coefficients, the calculated transition probabilities between each of the detection states, and observation probabilities determined from observed data associated with the noise pulses;
- filter out transient noise from the residual part of the signal based on the probable detection states determined for the coefficients;
- and
- combine the filtered residual part of the signal with the one or more extracted voiced parts of the signal,
- wherein the transient noise is at least one of feedback noise, fan noise, and button-clicking noise due to mechanical connection between the audio capture device and a keyboard or trackpad of the teleconferencing computing system.
Dependencies are inferred from the claim text.