Patricia A. Hollien

Effects of three parameters on speaking fundamental frequency

Speaking fundamental frequency levels and usage (SFF, F0) are of interest to many investigators who study human speech and voice. Substantial research in the area has been carried out; common foci include SFF as related to infant cry, age, gender, adolescent voice change, language, race, voice pathology, and so on. Yet there still are a number of relationships which are not well understood and three of them will be addressed in this project. They involve the long-held notions that (1) a secular trend exists with SFF being lowered over time, (2) the use of university students in research of this type will create bias because they are physically different from average individuals, and (3) SFF can vary systematically for different types of speech (especially for oral reading and extemporaneous speaking). Experiments assessing these questions were carried out, but only certain of the postulates were supported. That is, while some evidence of a secular trend was found, it appeared inconsequential during the past quarter of this century; second, although university students were found to be slightly larger than a cohort approaching the average population, only minor vocal differences were found. Finally, it was observed that, in general, oral reading resulted in higher mean SFFs than those for spontaneous speech. However, this difference was not robust and, due to reversals, the resulting metric did not appear to be of good predictive value for individual speakers.

Experimental data on “singer's formant”

Confusion exists relative to the presence or absence of a singing‐related “formant” in the phonatory output of individuals classified as artistic or premier singers. It has been suggested that this special formant occurs in the 3‐kHz region and that it accounts for the “ring” reportedly perceived when such professionals sing. Four groups of ten males and ten females were studied in order to test this notion. They were equally divided into the groups as follows: (1) artistic level singers, (2) student singers, (3) nonsinger musicians, and (4) nonsingers. All subjects produced the vowel /u/ at nine intensity/frequency combinations. Two evaluation procedures were applied: long term spectral analysis (energy in the 2700–3400‐Hz range as a function of total energy) and wave analysis (difference in dB between maximum peak and greatest peak in the 2850–3150‐Hz range). Both sets of data resulted in similar trends with all results statistically significant. Evidence of a singers formant was most pronounced in the phonatory output of the singers and to a lesser extent in the vocalizations by students; the effect was more apparent in males than in females. The presence of a “singers formant” appeared to be functionally related to the higher frequencies and especially to conditions requiring greater amounts of vocal intensity.

Speaking fundamental frequency (SFF) characteristics of children

While some information is available concerning the SFF characteristics of children, these data are based on relatively small groups of preschool and school‐aged (but prepubescent) subjects. Moreover, it has been suggested [AAPS Newsletter 3, 5 (1976)] that prepubescent girls actually may exhibit lower SFF levels than similar groups of boys. Accordingly, a standard reading passage was recorded for four groups of 30 boys and 30 girls each (N = 240) for the ages of 7, 8, 9, and 10 years; all subjects were drawn from the Gainesville, Florida public schools. Mean SFF levels were obtained via processing by the IASCP Fundamental Frequency Indicator (FFI‐8). The resultant data demonstrate a systematic—and expected—lowering of SFF through the ages 7–10 years. Further, the postulation that average f0 for girls is lower than that for boys was verified; however, the trend was slight and not statistically significant. Variability within the obtained data will be discussed—as will the findings when contrasted to simila...

Diver Auditory Sensitivity: Another Look at Bone Conduction

Support for the hypothesis that divers hear primarily by bone conduction was obtained by Hollien and Brandt [J. Acoust. Soc. Amer. 46, 384–387 (1969)]. In a further test of that hypothesis, the thresholds of seven submerged listeners were obtained (at frequencies of 0.25, 0.50, 1.0, 4.0, and 8.0 kHz) under three different conditions: (1) Wearing a full 316‐in. wet suit with no hood; (2) wearing a full 316‐in. wet suit with a 316‐in. hood; and (3) wearing a full 316‐in. wet suit and hood with 14‐in. rubber tubes passing through the hood to the meatuses. There were no significant differences between conditions two and three but thresholds were significantly lower in condition one. This finding provides further support for the hypothesis that underwater sound energy is transduced by bone conduction rather than by the normal middle‐ear linkage.

Helium Speech Unscramblers: A Critical Review

Mans attempt to probe and utilize “inner space” have, to a large degree, been hampered by inadequate voice communication. One of the specific sources of speech degradation is the use of helium as an inert breathing gas in the deep and/or saturation, diving situation. In turn, electronic devices have been developed which are designed to improve speech intelligibility distorted by the effects of high ambient pressures and HeO2 breathing mixtures. In order to evaluate the effectiveness of these HeO2 “unscramblers,” the Communication Sciences Laboratory at the University of Florida has undertaken a four‐part project: (1) to evaluate available unscramblers on line; (2) to test them off line; (3) to develop a standardized test for evaluating all types of unscramblers; and (4) to establish guidelines for the development of optimum equipment of this type. The present paper will discuss the following: (1) techniques for helium speech unscrambling; (2) protocols necessary to conduct system evaluation properly; (3)...