Abstract:
The objective of the research reported here was to perform an analysis of the voicing characteristics of sober and intoxicated speech in order to assess the possibility of detecting intoxication from the speech signal. Because the glottal excitation is the result of complicated and intricate motions by the vocal folds, it should be significantly affected by alcohol use. In this study, excitation parameters were extracted from non-nasalized vowels in eight utterances spoken in both sober and intoxicated conditions by four speakers. Fifteen parameters, including pitch, pitch contour, rms intensity measures, and measures of shimmer and jitter, were extracted directly from the speech waveform. As expected, the most significant differences between sober and intoxicated speech were in parameters measuring perturbations in adjacent pitch periods. Also as expected, there were no significant differences in more global parameters such as average pitch. Additionally, glottal waveforms were extracted from two of the speakers in both conditions using an adaptation of Wong's closed-phase glottal inverse-filtering method. Again, the most significant differences between sober and intoxicated glottal excitation were found in pitch-period-to-pitch-period variability. [Supported by a grant from the Alcoholic Beverage Medical Research Foundation to Indiana University.]