Huiwen Goy

Normative Voice Data for Younger and Older Adults

OBJECTIVES We constructed age- and gender-specific norms for healthy adults on a large number of speech and voice measures using standardized recording procedures. STUDY DESIGN Participants were 159 younger (mean = 19.1 years, standard deviation [SD] = 1.4) and 133 older (mean = 72.0 years, SD = 4.8) healthy native English male and female speakers who did not currently smoke and had typical hearing for their age group. METHODS Participants phonated the vowel [a] under various instructions and read an abbreviated version of the Rainbow Passage. Voice measures based on the productions of [a] included fundamental frequency (F(0)), jitter, shimmer, harmonics-to-noise ratio, noise-to-harmonics ratio, maximum phonation time, minimum phonation intensity, maximum pitch, and the Dysphonia Severity Index (DSI). Mean speaking fundamental frequency (SF(0)), SF(0) standard deviation (SF(0)SD), and signal intensity were measured from the reading passage. RESULTS Noteworthy age-related differences were found for males and females. Older females had a lower F0 and SF(0) and smaller SF(0)SD than younger females, but younger and older males did not differ. Shimmer increased with age for males, but neither jitter nor shimmer increased with age for females, whereas noise measures were similar for both ages. Younger and older males had a similar DSI, whereas older females had a higher DSI than younger females. CONCLUSIONS This study provides a unique database containing a wide variety of voice measures collected from a large sample of adults in good health using standardized recording procedures. Males and females differed on the type and extent of age-related vocal changes, but overall age-related differences were limited.

Older is always better: Age-related differences in vocabulary scores across 16 years.

Cross-sectional studies of cognitive aging compare age groups at 1 time point. It is unclear from such studies whether age-related cognitive differences remain stable across time. We present a cross-sectional investigation of vocabulary scores of 2,000 younger and older adults collected across 16 years, using the same laboratory and protocol. We found a steady decrease with year of testing and an advantage for older adults. An additive relation between age group and year of testing implied that age-related differences in vocabulary are independent of changes over time, suggesting that younger and older adults are similarly affected by changes in word usage.

Age-related difference in melodic pitch perception is probably mediated by temporal processing: empirical and computational evidence.

Objective: This study was designed to examine whether age-related differences in melodic pitch perception may be mediated by temporal processing. Temporal models of pitch suggest that performance will decline as the lowest component of a complex tone increases in frequency, regardless of age. In addition, if there are age-related deficits in temporal processing in older adults, this group may have reduced performance relative to younger adults even in the most favorable conditions. Design: Six younger adults and 10 older adults with clinically normal audiograms up to 8 kHz were tested in a melodic pitch perception task. In each trial, two consecutive four-note melodies were presented to the listener. Melodies were identical with the exception of one note in the second melody that was shifted in pitch. The listener was required to identify which note was shifted. All notes consisted of eight successive harmonic components, with the average lowest component manipulated to be the 4th, 8th, or 12th component of the harmonic series, with lower components being absent. Results: Age-related differences in melodic pitch perception were only apparent when stimulus parameters favored temporal processing of pitch. Furthermore, modeling a loss of periodicity coding yielded an outcome consistent with the observed behavioral results. Although younger adults generally outperformed older adults, about one-quarter of the older adults performed at levels that were equivalent to those of younger adults. The only follow-up tests that were able to differentiate these exceptional older adults were tests that would be sensitive to temporal processing: Fundamental frequency difference limens and 500 Hz pure-tone difference limens. In contrast, otoacoustic emissions and high-frequency pure-tone thresholds, which are more commonly associated with spectral processing deficits, were not able to differentiate older exceptional adults from older typical adults. Conclusion: Age-related declines in temporal processing contribute to deficits in melodic pitch perception. However, some exceptional older adults with normal audiograms preserve excellent temporal processing and continue to perform at levels that are typical of younger adults.

Quality of older voices processed by hearing aids: Acoustic factors explaining inter-talker differences

Hearing aid signal processing algorithms are often evaluated with professional recordings of voices. However, hearing aid users often listen to older talkers who may have poorer voices than younger talkers. The purpose of this study was to quantify the extent to which the acoustic and perceptual consequences of hearing aid digital signal processing algorithms differ for talkers that vary in their vocal characteristics. There were five talkers (2 male and 3 female) selected from a larger database of 60 talkers; their voices had good, moderate or poor quality based on perceptual data from younger and older listeners. The voices were presented in quiet and in the presence of babble noise (-5 to +20 dB SNR). The voices were processed with varying amounts of frequency compression, wide dynamic range compression and noise suppression (spectral subtraction). There were interactions between signal processing and voice characteristics as measured using the Hearing Aid Speech Quality Index (HASQI) and listener rati...