Acoustic and speaker variation in Dutch /n/ and /m/ as a function of phonetic context and syllabic position

In forensic speech science, nasals are often reported to be particularly useful in characterizing speakers because of their low within-speaker and high between-speaker variability. However, empirical acoustic data from nasal consonants indicate that there is a somewhat larger role for the oral cavity in nasal consonant acoustics than is generally predicted by acoustic models. For example, in read speech, nasal consonant acoustics show lingual coarticulation that differs by nasal consonant, and syllabic position also seems to affect realizations of nasal consonants within speakers. In the current exploratory study, the within- and between-speaker variation in the most frequent nasals in Standard Dutch, /n/ and /m/, was investigated. Using 3695 [n] and 3291 [m] tokens sampled from 54 speakers' spontaneous telephone utterances, linear mixed-effects modeling of acoustic-phonetic features showed effects of phonetic context that differed by nasal consonant and by syllabic position. A subsequent speaker-classification test using multinomial logistic regression on the acoustic-phonetic features seems to indicate that nasals displaying larger effects of phonetic context also perform slightly better in speaker classification, although differences were minor. This might be caused by between-speaker variation in the degree and timing of lingual coarticulatory gestures.