DSP based speech training of hearing impaired children

A study based on several digital signal processing (DSP) techniques to be used in the development of a computer-based speech trainer for hearing impaired children is presented. Children with congenital hearing impairments have difficulties in speaking, and even in making the basic sounds associated with speech. Speech therapists use specialized training methods to train such children. The dearth of qualified speech therapists and other facilities hinder the speech development of many children in need of such training in most of the third world countries. The speech trainer described in this dissertation was developed as an alleviation to the above problem. The training tool developed, will aid a child with initial guidance from an adult, to master the pronunciation of initial sounds taught in a speech therapy programme, in a game-like environment, with only a PC having multimedia facilities. Three DSP techniques were studied for application to the trainer. The objective was to identify whether an utterance by a trainee was acceptable or not compared to an utterance by a normal person. The three techniques were based on spectral analysis, for mam analysis and neural networks. The results with the spectral technique were found to be superior and were selected for use in the development of the training tool.// In its current status, the training tool can guide children in pronouncing the five vowel sounds, the first step in a speech therapy cours