A comparative acoustic analysis of the Laugh responses of 20- and 70-year-old males.

Several studies have documented age-related changes in speech or voice characteristics, but no study has reported differences across age groups in human laughter. The purpose of this investigation was to identify, describe, and compare the measurements of five acoustic correlates of elicited, spontaneous laughter in twenty- and seventy-year-old males. Five acoustic characteristics of laugh responses including Initial Laugh Fundamental Frequency (ILFo), Mean Laugh Fundamental Frequency (MLFo), Peak Laugh Fundamental Frequency (PLFo), Duration Laugh Response (DLR), and Laugh Bursts (LB) as well as Speech Fundamental Frequency (SFF) were analyzed across groups. Statistically significant differences were found between twenty- and seventy-year-old males in ILFo, MLFo, PLFo, and in the number of laughs per minute. Older respondents produced a relatively compressed fundamental frequency range of laugh behavior and fewer laugh responses per minute. These differences are congruent with age-related changes in speech and voice but also might be explained by other physiological or sociological variables.