摘要：The main goal of this research was to compare the acoustic–statistical measurements of similarity index (R) and dissimilarity index (SDDD) on the basis of long term average spectra (LTASS). The collected speech samples consisted of both spontaneous speech and reading of a standardized text which were recorded in controlled conditions. The recorded speakers (N = 86) originated from 8 larger and dialectically different Croatian towns. The cities chosen for this research represented Sthokavian dialect (Zadar, [ibenik, Dubrovnik), Chakavian dialect (Rijeka, Pula), Kaikavian dialect (Zagreb, ^akovec) and Chakavian–Sthokavian variety (Split). Speech samples (duration 60 s) were edited for each speaker in both conditions (filtered and non–filtered speech) and compared on the basis of LTASS – non filtered conditions (0 – 10 kHz) and filtered (0.8 – 4 kHz). Using index R and index SDDD intraspeaker variations and interspeaker variations were compared respectively for male and female speakers. Results of intraspeaker variations showed that average values of similarity index (R) in non–filtered conditions were between 0.94 for male speakers in reading texts to 0.98 for female speakers in reading text and spontaneous speech. Results of interspeaker variations showed lower values of index R in the non–filtered conditions: from 0.86 in spontaneous speech to 0.94 in reading text for female speakers. Average values of R in filtered conditions for intraspeaker variations were between 0.83 for both female and male speakers in spontaneous speech to 0.95 in reading texts. Average values of R index in filtered conditions for interspeaker variations were significantly lower; from 0.57 for male spontaneous speech to 0.9 for female reading texts. Average values of index SDDD in non–filtered conditions for intraspeaker variations were generally lower – from 2.27 for female speakers to 3 for male speakers in reading. SDDD index showed higher values in non–filtered conditions for interspeaker variations; from 4.75 in female reading speech and male spontaneous speech to 5.12 for male reading speech. In filtered conditions intraspeaker variations resulted with SDDD index between 2.14 for male reading speech to 3.01 for female spontaneous speech. As expected, results in filtered conditions for interspeaker variations showed higher values of SDDD index, from 3.06 for female to 4.71 for male reading speech. The differences between similarity index (R) in intraspeaker variations were statistically significant for female speakers (p and reading. Results of interspeaker variations showed statistically significant differences in similarity index (R) for male speakers (p speech) and female speakers (p statistically significant dissimilarity index (SDDD) differences for male speakers (p reading and p p measurement of similarity and dissimilarity indices are a useful method in speaker recognition in forensic phonetic expertise. Further on, results show that speaking conditions should not be neglected in forensic phonetic cases.
关键词：speaker identification; similarity index (R); dissimilarity index (SDDD); long term average spectra (LTASS); filtered speech; non–filtered speech; spontaneous speech; reading speech
