Impaired speech recognition Case study: Recognition of initial ‘r’ consonant in rhotacism affected pronunciations

The paper presents a study on one of the most common speech impairment in Romanian: the wrong pronunciation of the consonant “r”, called rhotacism. We propose a feature extraction method that can recognize rhotacism. The features extracted to characterize the interesting phonemes are the Mel-frequency cepstrum coefficients and their standard deviation over the signal duration. The final part of the paper presents a simple classification in correct or wrong pronounced of the resulting patterns based on the kNN algorithm and our feature extraction method. The system performance, expressed as accuracy in a classification experiment on a database containing correct and impaired pronunciations of the consonant “r”, is acceptable, validating the system to support the rhotacism diagnosis and therapy.