Effect of Ageing on Hearing Thresholds in the Low Frequency Region

Abstract

The hearing threshold for low frequency (LF) tones was measured in a pressure field to investigate the effects of ageing on hearing sensitivity. Participants were young adults around 20 years old and older adults over 60. Measurement results showed that the older listeners had a higher threshold, on average, than the young listeners. The difference of median thresholds between these two groups was about 10 dB at every measurement frequency. Furthermore, hearing abnormalities other than age-related hearing loss showed no great effect upon the LF thresholds. Comparison of LF thresholds and audiograms (i.e. mid and high frequency hearing) of the older listeners revealed only moderate correlation between them. These results suggest that older people retain good hearing sensitivity in the LF region, in contrast to their often-degraded sensitivity at higher frequencies. Therefore, in LF noise evaluation, we should carefully regard the possibility that older listeners can perceive a low level LF noise.

How large is the individual difference in hearing sensitivity?: Establishment of ISO 28961 on the statistical distribution of hearing thresholds of otologically normal young persons

“…The threshold distribution can be approximated as a normal distribution even at this very low frequency. On the basis of the results of this analysis, low-frequency threshold data in four studies [23][24][25][26] that were not used in ISO 226 and ISO 389-7 were additionally adopted to improve the accuracy of threshold distribution estimation. Fig.…”

The Statistical Distribution of Normal Hearing Thresholds for Low-Frequency Tones

“…The listener age also varied among studies. Kurakata et al [5] observed a threshold difference for LF tones between young adults around 20 years old and older adults over 60. The threshold difference was about 10 dB, irrespective of frequency.…”

“…The ageing effect on LF threshold is generally small, but not always negligible when a listener's age is, say, greater than 60. Threshold measurements of older people are described in [5]. Figure 2 shows that the SD of threshold distribution has a peak around 25 Hz: the individual differences of thresholds among listeners became largest at that frequency.…”

“…The present authors measured LF pure tone thresholds for otologically normal young people [5]. The threshold data of the 51 listeners at 10, 20, 40, or 80 Hz were submitted to the Lilliefors test for goodness-of-fit to a normal distribution (Matlab R2007a; The MathWorks Inc.).…”

“…The first five of the studies were cited in Møller and Pedersen [6] to compare threshold variations among studies. A measurement by the present authors [5] was also included. All of the studies listed in Table I examined healthy people with normal hearing for their LF threshold measurements and reported SDs of the threshold values.…”