Temporal integration of the contralateral acoustic-reflex threshold and its age-related changes

Abstract

Although numerous studies have investigated temporal integration of the acoustic-reflex threshold (ART), research is lacking on the effect of age on temporal integration of the ART. Therefore the effect of age on temporal integration of the ART was investigated for a broad-band noise (BBN) activator. Subjects consisted of two groups of adults with normal-hearing sensitivity: one group of 20 young adults (ten males and ten females, ages 18-29 years, with a mean age of 24 years) and one group of 20 older adults (ten males and ten females, ages 59-75 years, with a mean age of 67.5 years). Activating stimulus durations were 12, 25, 50, 100, 200, 300, 500, and 1000 ms. Significant main effects for duration and age were obtained. That is, as the duration increased, the acoustic reflex threshold for BBN decreased. The interactions of duration x age group and duration x hearing level were not significant. The result of pair-wise analysis indicated statistically significant differences between the two age groups at durations of 20 ms and longer. The observed age effect on temporal integration of the ART for the BBN activator is interpreted in relation to senescent changes in the auditory system.

Effects of age and background noise on processing a mistuned harmonic in an otherwise periodic complex sound

“…However, the N1m and P2m latencies were both longer in older adults. These age-related increases are consistent with prior research (Matilainen et al, 2010;Tremblay et al, 2002) and may reflect a slowing in auditory processing and/or a broadening of the temporal integration window (Emmer et al, 2006;Gleich et al, 2007;Huang et al, 2009), with older adults reaching a saturation in the auditory evoked responses at a longer latency than young adults. An agerelated decline in temporal integration could also account for the reduced ORNm amplitude observed in our prior study (Alain and McDonald, 2007).…”

Effects of age-related hearing loss and background noise on neuromagnetic activity from auditory cortex

“…In a prior study using the same stimuli and listening conditions (Alain et al, 2012), we found age-related increases in N1m and P2m latencies, which was consistent with earlier research (e.g.,Tremblay et al, 2002; Matilainen et al, 2010). The age-related increase in latency of auditory evoked responses may reflect a slowing in auditory processing and/or a broadening of the temporal integration window (Emmer et al, 2006; Gleich et al, 2007; Huang et al, 2009) with older adults reaching a saturation in the auditory evoked responses at a longer latency than young adults. The fact that the ORN latency was comparable between older adults with and without hearing loss suggests that mild hearing loss does not significantly delay the early computation needed to segregate the mistuned harmonic as a separate sound object.…”

Temporal Integration of the Contralateral Acoustic Reflex Threshold for a 1000 Hz Tonal Activator and Its Age-Related Changes

“…The activating stimulus was a 1000 Hz signal with the same durations used for the BBN activator by Emmer et al (2006), that is, 12, 25, 50, 100, 200, 300, 500, and 1000 msec. A 1000 Hz stimulus was chosen because this frequency seems to be unaffected by adaptation regardless of age.…”

“…The procedure was the same as that reported by Emmer et al (2006). One ear of each subject in each group was randomly selected.…”

“…The instrumentation and calibration for measurement of temporal integration, immittance, and pure tones were detailed in Emmer et al (2006). The sole modification for the current study was the stimulus used; that is, a 1000 Hz tone replaced BBN.…”