Chinchillas were trained with shock-avoidance procedures to discriminate or detect pure-tone frequency differences. Inital attempts at determining frequency-difference thresholds utilized a complex discrimination paradigm and a go-no-go response. Although discriminations of large frequency differences were obtained from chinchillas after considerable training, discriminations of small frequency...

Objective To determine average acoustic reflex thresholds in geriatric groups by assessing ipsilateral and contralateral acoustic reflex and reflex decay tests. Methods A total of 25 elders between ages 65-84 years (74.3±5.4) and 25 individuals between ages 18-45 years (30.4±4.2) were recruited for the study. After ear, nose, and throat examination, ipsilateral and contralateral acoustic refl...

OBJECTIVES The purpose of this study was to obtain behavioral hearing thresholds for frequencies between 0.125 and 20 kHz from a large population between 10 and 65 yr old using a clinically feasible calibration method expected to compensate well for variations in the distance between the eardrum and an insert-type sound source. Previous reports of hearing thresholds in the extended high frequen...

The effect of exposure to various types of noise (broadband, high-frequency or low-frequency) was studied in adult pigmented rats. Thresholds and amplitudes of middle latency responses (MLR) recorded from electrodes implanted on the surface of the auditory cortex were analyzed before and after noise exposure. Exposure to noise with intensities ranging from 105 to 120 dB for 1 h produced only te...

INTRODUCTION  In the dentistry practice, dentists are exposed to harmful effects caused by several factors, such as the noise produced by their work instruments. In 1959, the American Dental Association recommended periodical hearing assessments and the use of ear protectors. Aquiring more information regarding dentists', dental nurses', and prosthodontists' hearing abilities is necessary to pr...

How the brain processes signals in the presence of noise impacts much of behavioral neuroscience. Thresholds provide one way to assay noise. While perceptual thresholds have been widely investigated, vestibuloocular reflex (VOR) thresholds have seldom been studied and VOR threshold dynamics have never, to our knowledge, been reported. Therefore, we assessed VOR thresholds as a function of frequ...

Our objective was to determine the high-frequency hearing thresholds of women with multiple sclerosis (MS) and to investigate the presence of side dominance for high-frequency perception. We submitted 19 affected and 106 nonaffected women (controls) to high-frequency audiometry and classified them in subgroups according to their age (30-40, 40-50, and 50-60 years). We analyzed data through sele...