The language dependency of /m/ in native Dutch and non-native English

In forensic speaker comparisons, the current practice is to try to avoid comparisons between speech fragments in different languages. However, globalization requires an exploration of individual speech features that may show phonetic consistency across a speaker's languages. We predicted that the bilabial nasal /m/ may be minimally affected by the language spoken due to the involvement of the rigid nasal cavity in combination with a lack of fixed oral articulatory targets. The results show that indeed, L1 Dutch speakers (N = 53) had similar nasal formants and formant bandwidths when speaking in their L2 English as in their native language, suggesting language-independency of /m/ within speakers. In fact, acoustics seemed to rely more on the phonetic context than on the language spoken. Nevertheless, caution should still be exercised when sampling across languages when the languages' phoneme inventories and phonotactics show substantial differences.