Miyuki Tanaka

Apparatus and method for processing natural language and apparatus and method for speech recognition

An apparatus and a method for processing a natural language arranged so as to improve the speech recognition rate. In an example search section, the degree of similarity between each of a plurality of examples of the actual use of the language stored in an example data base and each of a plurality of probable recognition results output from a recognition section, and one of the examples corresponding to the highest degree of similarity is selected. A final speech recognition result is obtained by using the selected example. The example search section calculates the degree of similarity by weighting the degree of similarity on the basis of a context according to at least one of the examples previously selected.

A robust speech detection algorithm for speech activated hands-free applications

This paper describes a novel noise robust speech detection algorithm that can operate reliably in severe noisy car conditions. High performance has been obtained with the following techniques: (1) noise suppression based on principal component analysis for pre-processing, (2) robust endpoint detection using dynamic parameters, and (3) speech verification using the periodicity of voiced signals with harmonic enhancement. Noise suppression improves the SNR as compared with nonlinear spectrum subtraction by about 20 dB. This makes the endpoint detection operate reliably in SNRs down to -10 dB. In car environments, road bump noises are problematic for speech detectors causing mis-detection errors. Speech verification helps to remove these errors. This technology is being used in Sony car navigation products.