High resolution speech feature parametrization for monophone-based stressed speech recognition

This letter investigates the impact of stress on monophone speech recognition accuracy and proposes a new set of acoustic parameters based on high resolution wavelet analysis. The two parameter schemes are entitled wavelet packet parameters (WPP) and subband-based cepstral parameters (SBC). The performance of these features is compared to traditional Mel-frequency cepstral coefficients (MFCC) for stressed speech monophone recognition. The stressed speaking styles considered are neutral, angry, loud, and Lombard effect speech from the SUSAS database. An overall monophone recognition improvement of 20.4% and 17.2% is achieved for loud and angry stressed speech, with a corresponding increase in the neutral monophone rate of 9.9% over MFCC parameters.