Measurements of auditory discriminating thresholds of frequency (Δf), phase (Δφ)and intensity (ΔI) of repetitive clicks and hearing thresholds (HT) of pure tones were performed in human subjects with no history of...Measurements of auditory discriminating thresholds of frequency (Δf), phase (Δφ)and intensity (ΔI) of repetitive clicks and hearing thresholds (HT) of pure tones were performed in human subjects with no history of ear pathology the range of age being 17-67 years. The reference repetition rate of the clicks used was 500 pps and the frequencies for pure tone au-diometry were 500 Hz-8000Hz in octave steps. Aging changes of Δf, Δφ, ΔI and HT are obvious after the age of 40, while before 40; only Δφ, ΔI and HT of 8 kHz show mild but statistically significant increase with ape. Calculated on the basis of the 50 percentile curves from the experimental results (N=190), formulae of these aging changes can be expressed as:Δf = 0.0024X2 - 0.116X + 2.116 (pps), Δφ = 0.0010X2 - 0.050X + 1.343 (degrees), ΔI =0.0004X2 -0.016X+0.455 (dB) and, for 8000 Hz pure tone, HT = 0.0424X2 -2.15X+34.94 (dBnHL).展开更多
The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to al...The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and展开更多
文摘Measurements of auditory discriminating thresholds of frequency (Δf), phase (Δφ)and intensity (ΔI) of repetitive clicks and hearing thresholds (HT) of pure tones were performed in human subjects with no history of ear pathology the range of age being 17-67 years. The reference repetition rate of the clicks used was 500 pps and the frequencies for pure tone au-diometry were 500 Hz-8000Hz in octave steps. Aging changes of Δf, Δφ, ΔI and HT are obvious after the age of 40, while before 40; only Δφ, ΔI and HT of 8 kHz show mild but statistically significant increase with ape. Calculated on the basis of the 50 percentile curves from the experimental results (N=190), formulae of these aging changes can be expressed as:Δf = 0.0024X2 - 0.116X + 2.116 (pps), Δφ = 0.0010X2 - 0.050X + 1.343 (degrees), ΔI =0.0004X2 -0.016X+0.455 (dB) and, for 8000 Hz pure tone, HT = 0.0424X2 -2.15X+34.94 (dBnHL).
文摘The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and
