Parrot

Guillaume Vitte

Guillaume Pinto

Michael Herve

Julie Seris

Charles Fox

Alexandre Briot

Maurice Charbit

Jacques Prado

Guillaume Pinot

This method comprises steps of: a) partitioning () the spectrum of the noisy signal into a HF part and a LF part; b) operating denoising processes in a differentiated manner for each of the two parts of the spectrum with, for the HF part, a denoising by prediction of the useful signal from one sensor to the other between sensors of a first sub-array (R), by means of a first adaptive algorithm estimator (), and, for the LF part, a denoising by prediction of the noise from one sensor to the other between sensors of a second sub-array (R), by means of a second adaptive algorithm estimator (); c) reconstructing the spectrum by combining together () the signals delivered after denoising of the two parts of the spectrum, respectively; and d) selectively reducing the noise () by an Optimized Modified Log-Spectral Amplitude gain, OM-LSA, process.

Method for denoising an acoustic signal for a multi-microphone audio device operating in a noisy environment

The method comprises the steps of: digitizing sound signals picked up simultaneously by two microphones (N, M); executing a short-term Fourier transform on the signals (x(t), x(t)) picked up on the two channels so as to produce a succession of frames in a series of frequency bands; applying an algorithm for calculating a speech-presence confidence index on each channel, in particular a probability a speech that is present; selecting one of the two microphones by applying a decision rule to the successive frames of each of the channels, which rule is a function both of a channel selection criterion and of a speech-presence confidence index; and implementing speech processing on the sound signal picked up by the one microphone that is selected.

Method of selecting one microphone from two or more microphones, for a speech processor system such as a 'hands-free' telephone device operating in a noisy environment

The headset comprises: a physiological sensor suitable for being coupled to the cheek or the temple of the wearer of the headset and for picking up non-acoustic voice vibration transmitted by internal bone conduction; lowpass filter means for filtering the signal as picked up; a set of microphones picking up acoustic voice vibration transmitted by air from the mouth of the wearer of the headset; highpass filter means and noise-reduction means for acting on the signals picked up by the microphones; and mixer means for combining the filtered signals to output a signal representative of the speech uttered by the wearer of the headset. The signal of the physiological sensor is also used by means for calculating the cutoff frequency of the lowpass and highpass filters and by means for calculating the probability that speech is absent.

Combined microphone and earphone audio headset having means for denoising a near speech signal, in particular for a 'hands-free' telephony system

The equipment comprises two microphones, sampling means, and de-noising means. The de-noising means are non-frequency noise reduction means comprising a combiner having an adaptive filter performing an iterative search seeking to cancel the noise picked up by one of the microphones on the basis of a noise reference given by the other microphone sensor. The adaptive filter is a fractional delay filter modeling a delay that is shorter than the sampling period. The equipment also has voice activity detector means delivering a signal representative of the presence or the absence of speech from the user of the equipment. The adaptive filter receives this signal as input so as to enable it to act selectively: i) either to perform an adaptive search for the parameters of the filter in the absence of speech; ii) or else to 'freeze' those parameters of the filter in the presence of speech.

Audio equipment including means for de-noising a speech signal by fractional delay filtering, in particular for a 'hands-free' telephony system

A multi-microphone hands-free device operating in noisy surroundings implements a method of de-noising a noisy sound signal. The noisy sound signal comprises a useful speech component coming from a directional speech source and an unwanted noise component, the noise component itself including a lateral noise component that is non-steady and directional. The method operates in the frequency domain and comprises

Method of filtering non-steady lateral noise for a multi-microphone audio device, in particular a 'hands-free' telephone device for a motor vehicle

A multi-microphone hands-free device distinguishes between non-steady noise and speech and adapts the de-noising to the presence and characteristics of the detected non-steady noise without spoiling any speech that is present. In the frequency domain, the method comprises

Optimized method of filtering non-steady noise picked up by a multi-microphone audio device, in particular a 'hands-free' telephone device for a motor vehicle

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Paris, France

Guillaume Vitte