The purpose of this study was to examine the potential differences in selected acoustic measures of speech as a function of age, across sexes, and between families. The data used in this study were previously collected for a larger project on voice production at the University of Utah. Participants included 169 individuals, 79 men and 90 women, from 18 Utah families, ranging in age from 17 to 87 years. All participants had no history of articulation disorders, stroke or active neurologic disease, or severe-profound hearing loss. Participants were recorded reading two passages aloud in a sound booth. These two passages were selected as connected speech tasks from which to extract the following acoustic metrics: fricative spectral measures (center of gravity, standard deviation, skewness, and kurtosis), mean fundamental frequency (F0), semitone standard deviation (STSD), speaking time ratio, and cepstral peak prominence smoothed (CPPS). Results indicated significant aging effects on spectral center of gravity and skewness, mean F0, and STSD. There was a significant sex effect for spectral center of gravity and kurtosis, mean F0, speaking time ratio, and CPPS. Familial relationship had a significant effect for spectral skewness, STSD, and CPPS. Findings from the current study indicate that certain speech and voicing features point to a decline with age and that aging affects the speech of men and women differently. Additionally, these data suggest that related speakers may demonstrate similar patterns for prosody, voicing, and articulation behavior, although the statistical testing did not allow us to draw specific inferences about such similarities. These findings describe some normal variations in the speech production of persons of differing age, sex, and familial background. An understanding of these normal speech differences in healthy individuals is valuable for differentiating between typical and pathological speech patterns in a clinical setting.

The purpose of this study was to examine interference between concurrently performed speaking and driving tasks. Participants included 60 adults, 30 males and 30 females, with no history of communication disorders. They were divided into three different age groups of 20 participants each: younger (20s), middle-aged (40s), and older (60s). The participants were given a list of topics to consider and were instructed to select eight topics that they could talk about; they completed five practice trials of the driving simulator prior to the experimental recording to eliminate practice effects. Each participant completed the speaking task and driving task both separately and concurrently. The speaking task consisted of producing a monologue about the topics that they had selected. Dependent measures for speech included metrics relating to intensity, fundamental frequency, and the ratio of speaking to pausing time. The simulated driving task involved maintaining a constant speed and lane position on a freeway. Dependent measures for driving included metrics relating to speed, lane position, steering wheel position, and a count of steering wheel turns. Results indicated significant divided attention effects in speaking time ratio, intensity, speed, and steering wheel control. There was a significant age effect for intensity and fundamental frequency as the younger group had less variation with these variables compared to the other age groups. There was a significant age effect for lane position, steering wheel position, and speed as the younger group had less variation in lane and position compared to the other groups and the older group had more variation in speed and steering wheel position compared to the other groups. There was a significant gender effect for intensity and lane position as the females had less variation in intensity and more variation in lane position compared to the males. These findings suggest that divided attention conditions impact both speech and driving performance. The results also shed some light on the effects of age on concurrently performed speech and driving tasks. These findings imply that divided attention conditions should be incorporated in treatment to help patients generalize the skills learned in therapy to everyday communication.

The purpose of this study was to compare changes in acoustic and kinematic measures of articulation across soft, comfortable, and loud speech conditions. There were 19 participants, 9 male and 10 female, with age ranging from 20 to 34 with a median age of 25. Each participant had electromagnetic sensors glued to their tongue, jaw, and lips. It was anticipated that the acoustic measures would accurately reflect the kinematic measures of speech as articulation changed across the intensity levels. Vowel space area (VSA) and vowel articulation index (VAI) were computed from the three corner vowels, /α, i, u/. Articulatory-acoustic vowel space (AAVS), a sentence-level acoustic measure, was computed from the continuous formant histories for all voiced segments in a sentence. Kinematic-vowel space area (KVSA), kinematic-vowel articulation index (KVAI), and articulatory-kinematic vowel space (AKVS) were the kinematic equivalents of the acoustic measures, and were newly developed for the present study. Stroke metrics based on the speed history of the lingual movements were also used to reveal average kinematic features of the articulatory gestures in each participant's speech. The data revealed that the isolated acoustic and kinematic measures that used corner vowels (VSA, VAI. KVSA, KVAI) did not change significantly with intensity. The sentence-level continuous measures of articulatory working space (AAVS and AKVS) increased as speech intensity increased. The other sentence-level kinematic metrics also changed significantly with speech intensity, including increases in hull volume, onset speed, peak speed, mean speed, and distance. Stroke duration decreased as speech intensity increased. These findings suggest that measures based on isolated corner vowels are not as reflective as continuous measures of changes in articulatory movement in speech.