[Influence of aging on electrogustometric threshold]

Electrogustometric testing was carried out, with one researcher examining the electrogustometric threshold at three sites, in 461 normal cases, by TR-06 (Rion Co.), over a wide range. A multiple comparison procedure (Tukey-Kramer) was applied to age groups, revealing a significant increase in the threshold with advancing age; high threshold values were observed in the "60s and older" group for the chorda tympani nerve area (tongue tip) and the glossopharyngeal nerve area (tongue base), and in the "70s and older" group for the superficial greater petrosal nerve area (soft palate). As to the gender difference in women, a significant drop was observed in the late teens whereas a low tendency in all sites tested was not statistically, significant in other age groups. Differences between the right and the left sides were seen in most cases but were within 6dB. As to site differences, the soft palate threshold was higher than those of the tongue tip and the tongue base in all age groups. A significant decrease in the threshold of the tongue tip, as compared to the tongue base, was observed for those in their late teens, whereas minimal differences were noted in the other age groups and at other sites. The soft palate threshold was significantly reduced in smokers in their 30s and 40s as compared with non-smokers.