Speech enhancement aims to improve
speech
Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...
quality by using various algorithms. The objective of enhancement is improvement in
intelligibility and/or overall perceptual quality of degraded
speech
Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...
signal
A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology.
In ...
using
audio signal processing
Audio signal processing is a subfield of signal processing that is concerned with the electronic manipulation of audio signals. Audio signals are electronic representations of sound waves—longitudinal waves which travel through air, consisting ...
techniques.
Enhancing of speech degraded by noise, or noise reduction, is the most important field of speech enhancement, and used for many applications such as
mobile phone
A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...
s,
VoIP
Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...
,
teleconferencing systems,
speech recognition
Speech recognition is an interdisciplinary subfield of computer science and computational linguistics that develops methodologies and technologies that enable the recognition and translation of spoken language into text by computers. It is also ...
,
speaker diarization, and
hearing aids
A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers ...
.
Algorithms
The algorithms of speech enhancement for noise reduction can be categorized into three fundamental classes: filtering techniques, spectral restoration, and model-based methods.
[J. Benesty, M. M. Sondhi, Y. Huang (ed). ''Springer Handbook of Speech Processing''. pp.843-869. Springer, 2007. .]
* Filtering Techniques
:* Spectral Subtraction Method
:*
Wiener Filtering
In signal processing, the Wiener filter is a filter used to produce an estimate of a desired or target random process by linear time-invariant ( LTI) filtering of an observed noisy process, assuming known stationary signal and noise spectra, a ...
:*
Signal subspace
In signal processing, signal subspace methods are empirical linear methods for dimensionality reduction and noise reduction. These approaches have attracted significant interest and investigation recently in the context of speech enhancement, speec ...
approach (SSA)
* Spectral Restoration
:* Minimum Mean-Square-Error Short-Time, Spectral Amplitude Estimator (MMSE-STSA)
* Speech-Model-Based
See also
*
Audio noise reduction
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an u ...
*
Speech coding
Speech coding is an application of data compression to digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic da ...
*
Speech interface guideline
Speech interface guideline is a guideline with the aim for guiding decisions and criteria regarding designing interfaces operated by human voice. Speech interface system has many advantages such as consistent service and saving cost. However, for ...
*
Speech processing
Speech processing is the study of speech signals and the processing methods of signals. The signals are usually processed in a digital representation, so speech processing can be regarded as a special case of digital signal processing, applied to ...
*
Speech recognition
Speech recognition is an interdisciplinary subfield of computer science and computational linguistics that develops methodologies and technologies that enable the recognition and translation of spoken language into text by computers. It is also ...
*
Voice analysis
Voice analysis is the study of speech sounds for purposes other than linguistic content, such as in speech recognition. Such studies include mostly medical analysis of the voice ( phoniatrics), but also speaker identification. More controversial ...
References
* J. Benesty, M. M. Sondhi, Y. Huang (ed). ''Springer Handbook of Speech Processing''. Springer, 2007. .
* J. Benesty, S. Makino, J. Chen (ed). ''Speech Enhancement''. Springer, 2005. .
* P. C. Loizou. ''Speech Enhancement: Theory and Practice''. CRC Press, 2013. .
Speech processing
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