PatentDOI
Noise suppression system
TLDR
In this paper, an improved noise suppression system (400) was proposed which performs speech quality enhancement upon speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification.Abstract:
An improved noise suppression system (400) is disclosed which performs speech quality enhancement upon speech-plus-noise signal available at the input (205) to generate a clean speech signal at the output (265) by spectral gain modification. The noise suppression system of the present invention includes a background noise estimator (420) which generates and stores an estimate of the background noise power spectral density based upon pre-processed speech (215), as determined by the detected minima of the post-processed speech energy level. This post-processed speech (255) may be obtained directly from the output of the noise suppression system, or may be simulated by multiplying the pre-processed speech energy (225) by the channel gain values of the modification signal (245). This technique of implementing post-processed signal to generate the background noise estimate (325) provides a more accurate measurement of the background noise energy since it is based upon much cleaner speech signal. As a result, the present invention performs acoustic noise suppression in high ambient noise backgrounds with significantly less voice quality degradation.read more
Citations
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PatentDOI
Variable rate vocoder
Jacobs Paul E,Gardner William R,Lee Chong U,Gilhousen Klein S,Lam S Katherine,Ming-Chang Tsai +5 more
TL;DR: In this paper, a variable rate coding of frames of digitized speech samples is proposed, comprising the steps of determining a level of speech activity for a frame of digitised speech samples, selecting an encoding rate from a set of rates based upon the determined level of activity within said frame, and coding said frame according to a predetermined coding format for said selected rate wherein each rate has a corresponding different coding format.
PatentDOI
Noise cancellation apparatus
Douglas Andrea,Martin Topf +1 more
TL;DR: In this article, the authors propose an approach for reducing acoustic background noise for use with a telephone handset (10) or a boom microphone device (100) or an audio boom headset (401) or the like.
PatentDOI
Hearing aid device incorporating signal processing techniques
TL;DR: In this paper, a hearing compensation system for the hearing impaired comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a multiplicative AGC circuits.
PatentDOI
Adaptive, programmable signal processing and filtering for hearing aids
TL;DR: In this paper, the spectral energy analysis is carried out using pairs of high pass and low pass digital filters in cascade relation, with the output of each low pass filter being provided to the next pair of high-pass and low-pass filters.
Patent
Spectral subtraction noise suppression method
TL;DR: In this paper, a spectral subtraction noise suppression method in a frame-based digital communication system is described, where each frame includes a predetermined number N of audio samples, thereby giving each frame N degrees of freedom.
References
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Journal ArticleDOI
Suppression of acoustic noise in speech using spectral subtraction
TL;DR: A stand-alone noise suppression algorithm that resynthesizes a speech waveform and can be used as a pre-processor to narrow-band voice communications systems, speech recognition systems, or speaker authentication systems.
Journal ArticleDOI
Enhancement and bandwidth compression of noisy speech
Jae Lim,Alan V. Oppenheim +1 more
TL;DR: An overview of the variety of techniques that have been proposed for enhancement and bandwidth compression of speech degraded by additive background noise is provided to suggest a unifying framework in terms of which the relationships between these systems is more visible and which hopefully provides a structure which will suggest fruitful directions for further research.
Journal ArticleDOI
Speech enhancement using a soft-decision noise suppression filter
R. McAulay,M. Malpass +1 more
TL;DR: In this paper, a spectral decomposition of a frame of noisy speech is used to attenuate a particular spectral line depending on how much the measured speech plus noise power exceeds an estimate of the background noise.
Patent
Automatic gain selector for a noise suppression system
TL;DR: In this article, an automatic gain selector is disclosed for use with a noise suppression system which performs speech quality enhancement upon a noisy speech signal available at the input to generate a noise-suppressed speech signal at the output by spectral gain modification.
Patent
Automatic background noise estimator for a noise suppression system
TL;DR: In this paper, an improved background noise estimator (320) is disclosed for use with a noise suppression system (300) for generating an estimate of the background noise power spectral density provided to noise suppressor.