| Earlier studies have examined the effects of aging on the speech discrimination ability of human subjects and have found deficits with aging. However, it is difficult to isolate aging as the sole variable contributing to the deficits when conducting such studies. This study examined the effects of aging on spectral and temporal speech sound discrimination in Mongolian gerbils. The gerbil was proposed as the most suitable animal for such research since all aspects of its life, aside from natural aging process, can be controlled. Four different speech contrasts were used: /ba-da/, /ba-wa/, /ba-pha/, /ba-mba/. To verify normal hearing, absolute thresholds were also measured in the gerbils. A comparison was made among the difference limens obtained at “young age” (10–19 months), “middle age” (20–29 months), and “old age” (30–39 months). With the possible exception of /ba-mba/, results from the study showed no aging effects on the spectral and temporal speech discrimination in Mongolian gerbils. The results also suggest that gerbils could discriminate /ba-da/ and /ba-pha/ relatively more easily than /ba-wa/ and /ba-mba/. |
