Speech training aid

Abstract

A speech training aid compares a trainee's speech with models of speech, stored as sub-acoustic word models, and a general speech model to give an indication of whether or not the trainee has spoken correctly. An indication of how well the word has been pronounced may also be given. An adult operator enters the word to be tested into the training aid which then forms a model of that word from the stored sub-word speech models. The stored acoustic models are formed by first recording a plurality of words by a plurality of trainees from a given list of single words. These recordings are then processed off-line to give a basic acoustic model of an acceptable or correct sound for each phoneme in the context of the pre-and proceeding phonemes. The acoustic models are Hidden Markov Models. The limits of acceptable pronunciation, applied to different words and trainees, may be adjusted by variable penalty values applied in association with the general speech acoustic model. The training aid generates accumulated word costs for each trainee's utterance and uses these costs to indicate correctness of pronunciation.