Presbyacusis and the Auditory Brainstem Response

Abstract

Age-related hearing loss (ARHL or presbyacusis) is an increasingly common form of sensorineural hearing loss (SNHL) as a result of changing demographics, and the auditory brainstem response (ABR) is a common experimental and clinical tool in audiology and neurology. Some of the changes that occur in the aging auditory system may significantly influence the interpretation of the ABR in comparison to the ABRs of younger adults. The approach of this review will be to integrate physiological and histopathological data from human and animal studies to provide a better understanding of the array of age-related changes in the ABR and to determine how age-related changes in the auditory system may influence how the ABR should be interpreted in presbyacusis. Data will be described in terms of thresholds, latencies, and amplitudes, as well as more complex auditory functions such as masking and temporal processing. Included in the review of data will be an attempt to differentiate between age-related effects that may strictly be due to threshold elevation from those that may be due to the aging process.

Hearing and Age-Related Changes in the Gray Mouse Lemur

“…Consequently, the number of components is likely to be dependent on stimulus level (relative to hearing threshold) and neuronal synchrony. Given the fact that consecutive components can merge (Boettcher 2002;Tillein et al, 2012), the present results are consistent with previous findings and indicate similar generators, including the auditory nerve, the cochlear nucleus, and the superior olivary complex (Biacabe et al 2001;Boettcher 2002;.…”

“…Especially, the amplitudes of early components decrease with age (Sand 1991), which is in agreement with the present finding of a significantly lower amplitude in component III of old mouse lemurs. Boettcher (2002) suggested that the amplitude of the ABR is a direct function of the number of neurons and the synchrony of the neurons contributing to the response, as well as the value of the endocochlear potential (EP). Age-related changes in ABR amplitudes are suggested to be the consequence of a combination of a reduced number of neurons responding to the given stimulus, a reduced synchronization of activity of responding neurons and/or a reduction in the EP.…”

Age-Related Changes in the Relationship Between Auditory Brainstem Responses and Envelope-Following Responses

“…The ABR thresholds are an indicator of sound sensitivity, outer hair cell function, and the presence of a minimal number of functional auditory nerve synapses (Boettcher 2002;Kujawa and Liberman 2009;KonradMartin et al 2012). The ABR wave amplitudes are an indicator of overall auditory neuronal number and short-term synchrony of each generator and are a better predictor of peripheral synaptic function than ABR thresholds (Kujawa and Liberman 2009;Sergeyenko et al 2013).…”

Age-related differences in sensitivity to small changes in frequency assessed with cortical evoked potentials

“…Similar results were reported for the frequency modulated following response (FMFR), a steady-state evoked response thought to be related to frequency discrimination. Boettcher et al (2002) reported that FMFR response amplitudes increased as a function of modulation depth over depths of 0-40%, then reached a plateau , whereas Picton et al (1987) reported a relatively linear increase in response amplitude for modulation depths of 10-70%, with increases in amplitude tapering off at higher modulation depths . Additionally, increases in response amplitudes and latencies elicited by a change in frequency were comparable to changes in response amplitudes and latencies elicited by increases in intensity, such that responses to small changes in intensity have longer latencies and smaller amplitudes than responses to larger changes in intensity (Harris et al, 2007).…”