US 6,321,195 B1 · Speech recognition method

Abstract

The present invention relates to an automated dialing method for mobile telephones. According to the method, a user enters a telephone number via the keypad of the mobile phone, followed by speaking a corresponding codeword into the handset. The voice signal is encoded using the CODEC and vocoder already on board the mobile phone. The speech is divided into frames and each frame analyzed to ascertain its primary spectral features. These features are stored in memory as associated with the numeric keypad sequence. In recognition mode, the user speaks the codeword into the handset, which is analyzed in a like fashion as in training mode. The primary spectral features are compared with those stored in memory. When a match is declared according to preset criteria, the telephone number is automatically dialed by the mobile phone. Time warping techniques may be applied in the analysis to reduce timing variations.

Claims27

Dependent claims

In a telephone modulating an input speech and having a built-in vocoder for encoding a modulated speech signal, a speech recognition method comprising:

a training step of, if a user enters a telephone number and a speech corresponding to said telephone number, performing the encoding at said vocoder, detecting only a speech section using information output as a result of the encoding, and extracting and storing a feature of the detected speech section;
a recognition step of, if an input speech is received, performing encoding at said vocoder, detecting only a speech section using information output as a result of the encoding, extracting a feature of the detected speech section, comparing the extracted feature with features of registered words stored during said training step, and selecting a registered word having a feature most similar to that of the input speech;
and
a step of determining a result of the recognition to be right if a similarity of the registered word selected at said recognition step does not exceed a predetermined threshold and automatically dialing a telephone number corresponding to the recognized word, wherein said recognition step comprises extracting LSP parameters that have been encoded at said vocoder and transforming the extracted LSP parameters into pseudo-cepstrums.

1 more element

In a telephone modulating an input speech and having a built-in vocoder for encoding a modulated speech signal, a speech recognition method comprising:

a training step of, if a user enters a telephone number and a speech corresponding to said telephone number, performing the encoding at said vocoder, detecting only a speech section using information output as a result of the encoding, and extracting and storing a feature of the detected speech section;
a recognition step of, if an input speech is received, performing encoding at said vocoder, detecting only a speech section using information output as a result of the encoding, extracting a feature of the detected speech section, comparing the extracted feature with features of registered words stored during said training step, and selecting a registered word having a feature most similar to that of the input speech;
and
a step of determining a result of the recognition to be right if a similarity of the registered word selected at said recognition step does not exceed a predetermined threshold and automatically dialing a telephone number corresponding to the recognized word, wherein said recognition step comprises extracting stored representations of audio signals encoded by the vocoder and transforming said stored representation of audio signals into pseudo-cepstrums.

1 more element

Dependencies are inferred from the claim text.

Speech recognition method

Life of this patent

Speech recognition method

Life of this patent

Abstract

Claims27