Analysis of fundamental frequency reveals covariation in interview partners' speech

Spectral analysis of the fundamental frequency band in speech of interview partners reveals covariance of voice energy levels and thus a possible form of rudimentary social synchrony. Though this phenomenon of paralinguistic covariance has been observed by a number of researchers, techniques for examining it have not been exploited using modern instruments for Fast Fourier Transform analysis nor has the effect been statistically explicated in depth. This study reports on research showing that the acoustic signal conveying covariance information resides in the fundamental frequency band of the speech spectrum, a band which in itself has traditionally been considered inconsequential to perceived intelligible verbal communication. Acoustic signals from speech of four interview partners interacting with the author were analyzed in three frequency settings—2 KHz., .5 KHz., and .2 KHz.—to target the low frequency band in which the covariance phenomenon is most coherently transmitted. Analysis was performed using a dedicated instrument, the Fast Fourier Transform analyzer, to obtain spectra, and spectral output was processed statistically to produce relationships showing the covariance effect. Also, this paper addresses means by which potency of influences from technical artifacts, as introduced by instrumentation, interview environment, or statistical protocols are appraised. Research conclusions present an efficient, lucid, and reliable method for analyzing the paralinguistic mode of nonverbal behavior, and, in addition, offer evidence that the nonverbal, vocal channel of communication carries a signal embodying a semantic message. These conclusions raise some crucial questions regarding the influence of a hitherto unreported function of the fundamental frequency in voices of interview partners.I wish to acknowledge support of Bebe Lavin, Chairperson, Department of Sociology and Anthropology, Rudolph O. Buttlar, Dean, College of Arts and Sciences, Stephen Webster, Department of Sociology and Anthropology, and the Research Council, Kent State University.