Some general phonetic and forensic aspects of speaking tempo

Abstract

The comparability and compatibility of speech samples is of paramount importance to modern techniques of forensic speaker identification. This principle applies also to factors commonly referred to as speaking tempo, speech rate, speed of utterance, and the like, which may differ considerably as a function of various characteristics of the speaking situation. Consider, for example, a blackmailer's telephone call to a victim, i.e. a spontaneous text, often produced in a dialogic situation, and, on the other hand, a text (even the same text) read aloud from a transcript by a suspect and recorded directly over a microphone in a police station. With respect to speaking tempo the compatibility problem is enhanced by the fact that, other than, for instance, F0 and pitch, it cannot be attributed to a single phonetic parameter on the level of either production or perception. In this study the influence of a number of temporal variables which have been associated with speaking tempo in the literature have been investigated in three speaking conditions considered typical of the forensic setting. Furthermore, the potential influence of the telephone recording situation was investigated, a characteristic feature in the vast majority of speaker identification cases. Results from ten speakers and fifteen listeners indicate that speaking condition but not recording condition does in fact have an influence on speaking tempo in terms of both production and perception, with syllable rate, or rather the amount of pausing contained in this parameter, being the best temporal correlate. On the other hand, articulation rate remains almost entirely unaffected and is also remarkably constant within speakers. Therefore it may be regarded as a promising speaker-specific parameter for forensic speaker identification.

Taxa de elocução e taxa de articulação em corpus utilizado na perícia de Comparação de Locutores

“…Apesar de ser um elemento variável na fala, especialmente na fala espontânea, sujeito inclusive a modificações intencionais, as medidas de emprego do tempo na fala têm indicação de uso na perícia de Comparação de Locutores (CAO e WANG, 2011;ERIKSSON, 2012;FRENCH e HARRISON, 2007;FRENCH et al, 2010;GOLD, 2012;GOLD e FRENCH, 2011;HOLLIEN, 2002;JESSEN, 2007;KÜNZEL, 1997e ROSE, 2002. Tal indicação pode ser atribuída ao fato de que alguns indivíduos, além de manifestarem taxas associáveis a contextos comunicativos específicos, falam habitualmente mais rápido ou mais lento do que outros (MEIRELES e BARBOSA, 2009;TSAO et al, 2006e TSAO e WEISMER, 1997.…”

Towards a Methodology to Estimate Minimum Sample Length for Speaking Rate

“…Broadly considered, speaking rate is a temporal parameter that reflects how fast or slow speech is rendered in a given utterance. Technically, it can be defined as the rate of linguistic units uttered per time unit (KÜNZEL, 1997). Different linguistic units can be chosen as reference (e.g.…”

“…Studies reported in (KÜNZEL, 1997) suggest that speaking rate can be useful in speaker comparison tasks. There seems to be no discussion on the literature, though, on how long the speech sample should be so that the resulting global speaking rate can be said to be representative of the long-term behavior of a speaker.…”

Analyzing geospatial variation in articulation rate using crowdsourced speech data

“…Much of the research on speech rate in German is found in applied fields, such as speech technology (Siebenhaar, Zellner Keller & Keller, 2001;Trouvain, 2003) or forensic speaker identification (Jessen, 2007;Künzel, 1997). From a more forensic angle, Jessen (2007), for example, provided an initial description of 100 male German speakers' average articulation rates.…”