Noise suppression method and noise suppressor using noise suppression method

Abstract

A method for suppressing noise of a first signal captured via a primary microphone is provided. A primary and a reference microphone are arranged on a communication device to capture noise and intermittent speech. A determination is made whether the first signal comprises non-stationary signal components or substantially stationary noise, and whether the first signal comprises substantially far-field noise in case it was determined that it comprises non-stationary signal components. A noise power spectrum estimate of the first signal is updated with a stationary noise power spectrum estimate if the first signal is considered to comprise substantially stationary noise or a far-field noise power spectrum estimate if the first signal is considered to comprise substantially far-field noise. A frequency response is computed on the basis of the estimated noise power spectrum. Noise from the first signal is suppressed by applying the frequency response on the first signal.

Description

technical field [0001] The present application relates to a method for suppressing noise and a noise suppressor adapted to perform the proposed noise suppressing method. Background technique [0002] In general it can be said that speech communication involves sending a near-end speech signal to a far-end or distant user, where the speech enhancement problem consists in estimating a relatively clean speech signal from a captured noisy signal. There are several single microphone configurations that allow for improvement when noise suppression is considered. [0003] Simultaneous capture of the sound field using two different microphones allows possible use of spatial information and characteristics of the sound source from which the sound field captured by the microphones originates. These characteristics may be related to the relative placement of microphones on the mobile communication device and the design and use of the communication device. A reasonable estimate of the...

AI Technical Summary

Problems solved by technology

A disadvantage of WO2007 / 059255 (which relies on the assumption of little or even no gain difference between the captured signals by the microphones) is that, in practice, dual microphones mounted together on a mobile device will exhibit an arbitrary gain difference

However, many background noise environments (e.g., restaurants, airports, streets, or other public places) are not characterized by the presence of high-level non-stationary noise, which is not considered in known implementations based on spectral subtraction techniques The presence of noise, therefore, when applying these techniques, non-stationary noise components remain unfiltered in the signal sent to the remote user of the communication link

Images