This article is an investigation into how telephonic bandpass filters affect the speech signal with possible implications for forensic phonetics. The focus is on three different filters: The filter... Show moreThis article is an investigation into how telephonic bandpass filters affect the speech signal with possible implications for forensic phonetics. The focus is on three different filters: The filter used in landline connections; the AMR filter, which is used in most cell phone connections, and which delivers a worse signal than landline connections if coverage is poor; and the VoLTE filter, which delivers the most modern signal and is used in newer smartphones. The article shows how variation in the pronunciation of Danish /t/ can be used to identify a specific speaker, e.g. in the context of forensic phonetics. Three different sources of /t/-variation are presented: dialectal variation, variation in the pronunciation of foreign languages, and idiolectal variation among speakers of Standard Danish. For all of these sources of variation, it is shown how telephonic bandpass filters affect the speech signal, and especially how landline- and AMR-connections erase much of the variation as these connections do not transmit particularly high frequencies. The parameters which a forensic phonetician would look at in a high quality recording will often not be available in a recorded telephone conversation. The article thus suggests some other parameters in the speech signal which can be worth looking at if looking for variation in the production of /t/ in a telephone recording. Show less
We investigated the speaker-specificity of filled pauses across languages and time. The filled pauses uh and um contain speaker-specific information in a speaker’s native language. Since speakers... Show moreWe investigated the speaker-specificity of filled pauses across languages and time. The filled pauses uh and um contain speaker-specific information in a speaker’s native language. Since speakers are relatively unaware of their hesitation behavior, it might transfer from their first (L1) to their second language (L2). We examined filled pauses using several phonetic-acoustic features in spontaneous L1 Dutch and L2 English speech of 20 female speakers, recorded at two times, three years apart.Using linear mixed-effects models, we found that speakers differ in their first and second formants of uh and um in L1 versus L2, while duration and fundamental frequency remain stable. Speaker classification models trained on filled pauses in one language perform worse – but still relatively well – on the other language. With the exception of a few speakers, hesitation behavior remained stable over time. In spite of L1-L2 differences, some speaker characteristics of filled pauses remain. Show less
