Temporal acuity for brief gaps in noise was studied in mice of different ages (1-36 months) from strains with differing susceptibility to age-related hearing loss, using reflex modification audiometry. Prepulse inhibition of the acoustic startle reflex (ASR) increased with gap depth (GD: 10-40 dB in 70 dB SPL noise) and lead time (LT: 1-15 ms). The increase in inhibition with LT followed an exp...

Endocochlear, retrocochlear and/or central origin hearing damage may be related to the absence of appropriate levels of thyroid hormone during morphogenesis and/or auditory system development. Hearing disorders related to the thyroid are not well studied, despite speculation on the pathophysiological mechanisms. The objective of this review was to characterize the main pathophysiological mechan...

We reviewed the literature on the availability of auditory tests that determine, prior to being affected by significant hearing loss, to what extent an individual is susceptible to noise. The predictive power of tests that determine the acoustic reflex responsivity, and both temporal integration and non-linearities of the hearing system, may be large, whereas the predictability of tests that de...

Historically, the ipsilateral acoustic reflex (IAR) has played a prominent role in middle ear screening protocols. However, in 1990, the American Speech-Language-Hearing Association's revised guidelines, "Screening for Hearing Impairment and Middle Ear Disorders," deleted the IAR as a screening parameter. This decision was based on studies that demonstrated that the inclusion of the IAR resulte...

PURPOSE To analyze the otoacoustic emissions (OAE) of the newborn hearing screening of infants born to HIV-seropositive mothers. METHODS It was carried out the Transient-Evoked OAE and the research of cochleopalpebral reflex in 247 full-term newborns with no risk factors for hearing. The Control Group (CG) comprised 167 infants, and the Research Group (RG), 80 infants that had been exposed to...

The mammalian auditory system contains descending neural pathways, some of which project onto the cochlea via the medial olivocochlear (MOC) system. The function of this efferent auditory system is not entirely clear. Behavioral studies in animals with olivocochlear (OC) lesions suggest that the MOC serves to facilitate sound localization in noise. In the current work, noise-induced OC activity...

The dynamic adjustment of hearing sensitivity and frequency selectivity is mediated by the medial olivocochlear efferent reflex, which suppresses the gain of the 'cochlear amplifier' in each ear. Such efferent feedback is important for promoting discrimination of sounds in background noise, sound localization and protecting the cochleae from acoustic overstimulation. However, the sensory driver...

• Vol 9 • November 2007 814 There is an intriguing connection between renal diseases and hearing disorders. The incidence of sensorineural hearing loss among patients with chronic renal failure is considerably higher than in the general population. The incidence is about 46–77% according to different studies, ranging from mild to severe hearing loss [1,2]. The etiology of this phenomenon is not...

UNLABELLED Auditory processing depends on afferent and efferent auditory pathways integrity. The efferent auditory system may be assessed in humans by two non-invasive and objective methods: acoustic reflex and otoacoustic emissions suppression. AIM Analyze the efferent auditory system activity by otoacoustic emission suppression and acoustic reflex sensitization in human subjects with audito...

Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by su...