The purpose of this investigation is to shed some more light on the conflicting views about a number of acoustic parameters which might carry information on some general somatic features of the speaker. In an experiment, average fundamental frequency (F₀) values of 105 male and 78 female adult subjects were correlated with their individual height and weight data. No significant correlations between acoustic and physical parameters were found. The results are discussed with respect to earlier studies with completely different approaches to the issue, namely direct estimation of physical traits from the speech signal by listeners.

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.

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The problems associated with earwitness lineups, or voice parades, are of growing concern. First, they are becoming more common; second, they are being conducted by individuals who are not competent to carry them out; third, no adequate criteria for their proper use have been published. In response, the membership of the International Association of Forensic Phonetics have undertaken to review the specific elements associated with this problem, identify their nature/extent and establish criteria for their proper construction and use. The first stage has been to present a series of formal papers on the subject (see text) and the second to provide this summary review of the problem and its background. The third stage has been to constitute an IAFP working committee charged with the development of a set of criteria for consideration by the full membership at the 1995 conference (Orlando, Florida). If the IAFP membership adopts these criteria, they will be published. Finally, the members of this new committee are A. P. A. Broeders (Netherlands), P. French (UK) , H. Hollien (USA), R. Huntley (USA) and H. Kunzel (Germany).

Speech scientists often have to work with speech signals that have been transmitted over the telephone. Although the acoustic properties of telephone transmission such as the band-pass filter characteristics are well known, little attention has been paid to their effect on the measurement of speech parameters. This study deals with artefacts introduced by the lower cut-off slope of the transmission channel on vowel formants. For theoretical reasons, frequency components may be assumed to be attenuated the lower they are. Therefore F1 of most vowels can be expected to be affected most. Attenuation of the lower components of a formant will necessarily increase the relative weight of the higher components for the determination of a formant and thus cause an artificial upward shift of its centre frequency. An empirical investigation with directly and telephone-transmitted samples from ten male and ten female subjects shows that the predicted effect on F1 does in fact occur for all tested vowels except /a/, whose F1 is too high to be affected by the slope of the band-pass. The consequences of measurement errors arising from such artefacts are discussed with special reference to speaker identification and empirical dialectology.