Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

ETSI standard on noise-robust feature extraction for distributed speech recognition

In 1999, a standardisation in ETSI started on how speech recognition could be improved over mobile networks. The intention was to lower the influence of noisy environments, bandwidth limitations, codec effects and transmission errors, which decrease the recognition performance. A major leap has been gapped by introducing distributed processing of the acoustic data, i.e. generating the feature vectors of the signal in the terminal and transmitting these vectors to a backend, which performs the remaining decoding in the recognition process. Distributed Speech Recognition (DSR) could overcome most of the restrictions mentioned before and can - by using an excellent noise-reduction method - improve the quality of the speech signal.

SMADA has contributed to this standardisation through France Telecom and Alcatel by providing algorithms for noise robust feature extraction in a first evaluation round, which had so far the best performance.

For the second round the consortium teamed up with another ETSI member and developed together the winning proposal for the noise-robust front-end. This reduces the recognition errors in a defined evaluation set by more than 50% against standard mel-cepstrum feature extraction.

The result has become in October 2002 a formal ETSI standard and is currently discussed in 3GPP for implementation as codec for speech-enabled services in 3G networks. This result of SMADA will have major commercial value in the near and mid-term future when speech-enabled and multimodal services become available in 2,5-3 G mobile networks. It is foreseeable that after 2007 new mobile phones will be equipped with these software modules similar to today's WAP browsers.


More information on the SMADA project can be found on the project�s website:

Informazioni correlate

Reported by

See on map