摘要:
The application relates to a method for audio signal processing. The application further relates to a method of processing signals obtained from a multi-microphone system. The object of the present application is to reduce undesired noise sources and residual echo signals from an initial echo cancellation step. The problem is solved by receiving M communication signals in frequency subbands where M is at least two; processing the M subband communication signals in each subband with a blocking matrix ( 203,303,403 ) of M rows and N linearly independent columns in each subband, where N >=1 and N , to obtain N target-cancelled signals in each subband; processing the M subband communication signals and the N target-cancelled signals in each subband with a set of beamformer coefficients ( 204,304,404 ) to obtain a beamformer output signal in each subband; processing the communication signals with a target absence detector ( 309 ) to obtain a target absence signal in each subband; using the target absence signal to obtain an inverse target-cancelled covariance matrix of order N ( 310,410 ) in each band; processing the N target-cancelled signals in each subband with the inverse target-cancelled covariance matrix in a quadratic form ( 312, 412 ) to yield a real-valued noise correction factor in each subband; using the target absence signal to obtain an initial estimate ( 311, 411 ) of the noise power in the beamformer output signal averaged over recent frames with target absence in each subband; multiplying the initial noise estimate with the noise correction factor to obtain a refined estimate ( 417 ) of the power of the beamformer output noise signal component in each subband; processing the refined estimate of the power of the beamformer output noise signal component with the magnitude of the beamformer output to obtain a postfilter gain value in each subband; processing the beamformer output signal with the postfilter gain value ( 206,306,406 ) to obtain a postfilter output signal in each subband; processing the postfilter output subband signals through a synthesis filterbank ( 207,307,407 ) to obtain an enhanced beamformed output signal where the target signal is enhanced by attenuation of noise signal components. This has the advantage of providing improved sound quality and reduction of undesired signal components such as the late reverberant part of an acoustic echo signal. The invention may e.g. be used for headsets, hearing aids, active ear protection systems, mobile telephones, teleconferencing systems, karaoke systems, public address systems, mobile communication devices, hands-free communication devices, voice control systems, car audio systems, navigation systems, audio capture, video cameras, and video telephony.
摘要:
[Object] To provide a speech intelligibility improving apparatus capable of generating highly intelligible speech in various environments without unnecessarily amplifying sound volume. [Solution] A speech intelligibility improving apparatus 250 includes: an envelope surface extracting unit 292 extracting, from a spectrum of speech signal 254 as an object of processing, a curve representing a general outline of peaks of spectral envelope in contact with or along local peaks of spectral envelope of the spectrum; a noise adapting unit 300 modifying spectrum of speech signal 254 based on the curve extracted by envelope surface extracting unit 292; and a sinusoidal wave speech synthesizing unit 305 generating a modified speech signal 260 for the speech improved in intelligibility based on the spectrum modified by noise adapting unit 300.
摘要:
A method for optimizing the speech intelligibility in a passenger compartment of a vehicle comprises establishing an acoustic room model of the passenger compartment, establishing background noise data inside and outside the compartment, establishing speaker data, determining a speech intelligibility factor on the basis of the acoustic room model, the background noise data and the speaker data at at least one first test point in the compartment; comparing the determined speech intelligibility factor with a predetermined speech intelligibility factor and modifying at least one of the speaker characteristics, the geometrical layout and acoustically active material of at least one installation in the compartment in case the predetermined speech intelligibility factor exceeds the determined speech intelligibility factor. Thereby, physical tests may be minimized and optimal speech intelligibility can be ensured.
摘要:
A method of treating an audio signal is disclosed, comprising introducing a phase shift to the audio signal, the magnitude of the phase shift being dependent upon the frequency of the audio signal. A signal control system implementing the method is also disclosed, described for an active loudspeaker having at least one sound transducer, each sound transducer having an amplifier connected directly thereto, the signal control system provided between a signal source and the amplifier and comprising crossover means arranged to deliver a frequency limited portion of the signal to the amplifier; and phase shift means arranged to introduce a frequency dependent phase shift to the signal prior to being input to the amplifier, wherein the magnitude of the phase shift is dependent upon the frequency of the audio signal. The method and system increases the perceived clarify of the sound by the listener.
摘要:
The application relates to a method for audio signal processing. The application further relates to a method of processing signals obtained from a multi-microphone system. The object of the present application is to reduce undesired noise sources and residual echo signals from an initial echo cancellation step. The problem is solved by receiving M communication signals in frequency subbands where M is at least two; processing the M subband communication signals in each subband with a blocking matrix ( 203,303,403 ) of M rows and N linearly independent columns in each subband, where N >=1 and N
摘要:
A set of signal measures is received, wherein each signal measure in the set of signal measures corresponds to a respective audio signal received by a device in a media playback system which is processed based on a first set of audio processing algorithms. A plurality of signal measures is identified in the set of signal measures. Audio signals corresponding to the identified plurality of signal measures are processed by one or more devices in the media playback system to improve a signal measure of each of the audio signals. The audio signals are processed based on a second set of audio processing algorithms. The processed audio signals are then combined into a combined audio signal.
摘要:
A crosstalk cancelation technique reduces feedback in a shared acoustic space by canceling out some or all parts of sound signals that would otherwise be produced by a loudspeaker to only be captured by a microphone that, recursively, would cause these sounds signals to be reproduced again on the loudspeaker as feedback. Crosstalk cancelation can be used in a multichannel acoustic system (MAS) comprising an arrangement of microphones, loudspeakers, and a processor to together enhance conversational speech between in a shared acoustic space. To achieve crosstalk cancelation, a processor analyzes the inputs of each microphone, compares it to the output of far loudspeaker(s) relative to each such microphone, and cancels out any portion of a sound signal received by the microphone that matches signals that were just produced by the far loudspeaker(s) and sending only the remaining sound signal (if any) to such far loudspeakers.
摘要:
A multi-mode speech communication system is described that has different operating modes for different speech applications. A speech service compartment contains multiple system users, multiple input microphones that develop microphone input signals from the system users to the system, and multiple output loudspeakers that develop loudspeaker output signals from the system to the system users. A signal processing module is in communication with the speech applications and includes an input processing module and an output processing module. The input processing module processes the microphone input signals to produce a set user input signals for each speech application that are limited to currently active system users for that speech application. The output processing module processes application output communications from the speech applications to produce loudspeaker output signals to the system users, wherein for each different speech application, the loudspeaker output signals are directed only to system users currently active in that speech application. The signal processing module dynamically controls the processing of the microphone input signals and the loudspeaker output signals to respond to changes in currently active system users for each application.