M. Sigmund and Z. Brabec (Czech Republic)
Speech signal, spectral analysis, stress detection.
This paper deals with speech signal spoken by speaker
under psychological stress. The investigation of speaker’s
stress is based on specific changes in short-time spectrum
of vowel phonemes. For each selected signal segment, the
spectrum was computed by means of two different
approaches: Fourier transform and chirp transform.
Comparative results between both spectra served for
speaker’s stress identification. In case of speech under
stress, the obtained spectra differ towards the higher
frequencies due to enhanced pitch modulation observed in
the envelope of the chirp spectrum. For use in our
experiments, a new database of speech under stress
consisting of data collected during oral examinations at
our university was created.