Frequency discrimination thresholds were measured from five chinchillas for harmonic tone complexes having a fundamental frequency of 250 Hz. Stimuli consisted of the fundamental frequency and the second through 10th harmonics with individual components added in either cosine phase or random phase. In general, thresholds were independent of overall level for sound levels between 47 and 77 dB SP...

BACKGROUND A dead region is a region in the cochlea where the inner hair cells and/or neurons are functioning very poorly, if at all. We have shown that, for people with sensorineural hearing loss, thresholds for detecting sinusoidal amplitude modulation (AM) of a sinusoidal carrier were lower for ears with high-frequency dead regions, as diagnosed using the threshold-equalizing noise test, cal...

At high frequencies, interaural time differences (ITDs) are conveyed by the sound envelope. Sensitivity to envelope ITDs depends crucially on the envelope shape. Reverberation degrades the envelope shape, reducing the modulation depth of the envelope and the slope of its flanks. Reverberation also reduces the envelope interaural coherence (i.e., the similarity of the envelopes at two ears). The...

This study assessed the effects of apical hair cell destruction on the detection and discrimination of low-frequency stimuli. Monauralized chinchillas were trained using operant conditioning and positive reinforcement to respond to pure-tone stimuli in the absence and the presence of a high-pass noise masker. Following the collection of the baseline absolute thresholds, psychophysical tuning cu...

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk fact...

OBJECTIVES Changes in hearing thresholds were determined by standard and high-frequency audiometry in subjects exposed to occupational noise for long durations. PATIENTS AND METHODS Hearing thresholds were measured between 250 and 16000 Hz frequencies by standard and high-frequency audiometry in 64 male workers (mean age 42 years; range 31 to 55 years) of a hydroelectric power plant and in 30...

Adult canaries (Serinus canarius) from a closebred colony of the Belgian "Waterslager" strain were trained with operant techniques to respond to pure tones. A psychophysical tracking procedure was used to measure absolute auditory thresholds in quiet and in noise. Absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB higher (4-5 standard deviatio...

INTRODUCTION Research has shown that hearing loss in musicians may cause difficulty in timbre recognition and tuning of instruments. AIM To analyze the hearing thresholds from 250 Hz to 16,000 Hz in a group of music students and compare them to a non-musician group in order to determine whether high-frequency audiometry is a useful tool in the early detection of hearing impairment. METHODS ...

Are differences in luminance spatial frequency between surfaces that overlap in depth useful for surface segmentation? We examined this question, using a novel stimulus termed a dual-surface disparity grating. The dual-surface grating was made from Gabor micropatterns and consisted of two superimposed sinusoidal disparity gratings of identical disparity-modulation spatial frequency and orientat...