Mandarin speech input method for Chinese computers and a mandarin speech recognition machine

A speech recognition apparatus for Mandarin speech including high level, high rising, low dipping and high falling lexical tones, comprising:

• a speech signal filter for receiving a speech signal and creating a filtered analog signal;
• an analog-to-digital (A/D) converter connected to the speech signal filter for converting the filtered analog signal to a digital speech signal;
• a computer connected to the A/D converter for receiving and processing the digital signal;
• a pitch frequency detector connected to the computer for detecting characteristics of the pitch frequency of the speech signal thereby recognizing tones in the speech signal;
• a speech signal pre-processor connected to the computer for detecting the endpoints of syllables of speech signals thereby defining a beginning and ending of a syllable;
• a Hidden Markov Model processor connected to the computer for determining degrees of match between the speech signal and a syllable model, a tone model and a language model and recognizing speech signal syllables based on the degrees of match;
• a training apparatus connected to the computer for training an initial part Hidden Markov model and a final part Hidden Markov model and for training a syllable model based on trained parameters of the initial part Hidden Markov model and the final part Hidden Markov model.

A Mandarin tone recognition method comprising steps of:

• dividing training syllable utterances into five groups according to tones of the syllable utterances;
• training a Hidden Markov Model (HMM) on the five groups of training syllable utterances to create a Mandarin tone model;
• operating on an object speech sample with the Mandarin tone model;
• recognizing the object speech sample as an object Mandarin tone based on a degree of match of the object speech sample to the Mandarin tone model;
• representing the object speech sample as a Mandarin tone in accordance with the object Mandarin tone.