Recent Studies of Fundamental Vocal Pitch in Speech
Authors: Fairbanks Grant 
Published: September 2005

During recent years several studies of vocal pitch in speech of various types have been made at the University of Iowa by means of measurement of the fundamental sound wave frequency from phonograph records.

One investigation was concerned with the voices of well-known actors and actresses, disclosing among other data median pitch levels of 140.7 and 233.2 c.p.s. for the respective groups, with total pitch ranges in the neighborhood of 12 tones.

In a second experiment five actors simulated different emotions successfully in five readings of the same material. Simulation of contempt was found to be characterized by a range of 10.5 tones about a median of 124.3 c.p.s.; measurements of simulations of anger revealed a mean range of 10.3 tones about a median of 228.8 c.p.s., and a more rapid rate of pitch change [25.6 tones/sec.] than the other emotions studied: the highest median pitch level [254.4 c.p.s.] and widest range [11.2 tones] were found in fear; in grief the mean range was 9.0 tones with a median of 135.9 c.p.s., the mean extent of inflections [1.7 tones] was the narrowest and the rate of pitch change [15.6 tones/sec.] the slowest of the five emotions; the narrowest range [7.8 tones] and the lowest median pitch level [108.3 c.p.s.] were measured in simulations of indifference. Most of the subjects employed total pitch ranges of over 18 tones in the simulation of all five emotions. Another study investigated the pitch usage of carefully selected superior male speakers reading a 55-word test passage, and found a mean total range of 10.5 tones about a median level of 132.1 c.p.s. In the latter measure individual subjects were grouped closely about this value. The pitch usage of these subjects in speech was related to their total singing ranges including falsetto, these ranges averaging 20.4 tones. It was found that the pitches used in the measured samples of speech lay within the lower fractions of the singing ranges, and that the ratio of the extent in tones between the lowest sung tones and the median pitch levels in speech to the total singing ranges averaged 0.25.

In a fourth experiment the same trained subjects re-read the test passage in response to instructions to read with more variability of pitch, with less variability of pitch, at a higher pitch level and at a lower pitch level. Extremes were avoided. Measurements revealed that the subjects followed instructions, and certain characteristic features of pitch variability were disclosed. Of interest was the finding that pitch level and pitch variability tended to vary concomitantly, i.e., increased variability was accompanied by a rising pitch level and vice versa.

Another investigation made a preliminary exploration of the pitch aspects of voice change in the male. Ten-year-old, 14-year-old, 18-year-old and adult subjects were studied. The two younger groups were found to have median pitch levels in the neighborhood of the values reported for adult females, while the 18-year-old subjects used levels approximately equal to those of the adult male group. Wave-to-wave measurement of so-called “voice breaks” revealed several interesting features. (1) Almost as many breaks were found at 10 years as at 14 years. (2) Downward breaks, although outnumbered by upward breaks, were frequent. (3) Breaks averaged approximately one octave in extent. (4) All breaks measured were made up to and down from the median pitch levels of speech or their vicinity; none were found above these levels. However, in two atypical cases of voice change, not included in the above groups, the breaks departed from this typical location below the median.

These experiments are immediately suggestive of further researches, some of which are under way at present.