14th International Congress of Phonetic Sciences (ICPhS-14)

San Francisco, CA, USA
August 1-7, 1999

Similarity Degree between Speakers on the Basis of Short-Time FFT Spectra

Tuija Niemi-Laitinen (1,2), Antti Iivonen (1), Kirsi Harinen (1)

(1) Department of Phonetics, University of Helsinki, Finland,
(2) Crime Laboratory of Finnish National Bureau of Investigation

The experiments showed that FFT spectra can be used for the expression of the similarity degree between two speakers. The similarity measure is based on the mean correlation coefficient (Pearson) obtained in a comparison of spectral data representing 12 phonemes. In all comparisons inter-speaker similarity appeared to be smaller than intra-speaker similarity. All technical devices were kept unchanged in the comparison of speaker pairs. Smoothed linear spectra and a 45 Hz broad filter were applied in the FFT analysis. The comparisons made with stressed syllable data showed more inter-speaker similarity than the data in which stress was disregarded. Some phonemes showed more individual character than others. In different contexts the phonemes showed different similarity degrees. Two forensic cases will be discussed.

Full Paper

Bibliographic reference.  Niemi-Laitinen, Tuija / Iivonen, Antti / Harinen, Kirsi (1999): "Similarity degree between speakers on the basis of short-time FFT spectra", In ICPhS-14, 153-156.