The nature of age-related improvements in auditory sensitivity was explored by comparing behavioral and auditory brainstem response (ABR) thresholds in 3- and 6-month-old infants and in adults. Thresholds were estimated for tone pips at 1, 4, and 8 kHz, presented at a rate of 13.3/s. The time course of development of the two response measures was compared, and the correlation between thresholds...

The effects of rise time and center frequency on the auditory brainstem response (ABR) elicited by high-frequency tone bursts were examined in six normal-hearing adults. Tone bursts with rise times of 0.1, 0.25, 0.5, and 1.0 msec, duration of 2 msec, and center frequencies of 8, 10, and 12 kHz were used in this study. The absolute latencies of waves I, III, and V were obtained in all subjects, ...

This study evaluated the effects of stimulus repetition rate, phase, and frequency on the auditory brainstem response (ABR) in normal-hearing neonates and adults. In both neonates and adults, the results clearly showed large ABR wave V latency differences between condensation and rarefaction for low-frequency stimuli. Phase dependent latency effects are believed to be a result of the phase-sens...

In order to elucidate why many elderly listeners have difficulty understanding speech under reverberation, we investigated the relationship between word intelligibility and auditory brainstem responses (ABRs) in 28 elderly listeners. We hypothesized that the elderly listeners with low word intelligibility scores under reverberation would show degraded subcortical encoding information of reverbe...

Traditionally the study of fish hearing is achieved either by psychophysical method (e.g., behavioral training) or invasive electrophysiological recording (e.g., microphonics, single unit recording). A non-invasive, the auditory brainstem response (ABR) recording method is developed to study fish hearing. With the use of the ABR method and the removal of gas from various gas holding structures,...

iChirp-evoked auditory brainstem responses (ABRs) yield a larger wave V amplitude at low intensity levels than traditional broadband click stimuli, providing a reliable estimation of hearing sensitivity. However, advantages of iChirp stimulation at high intensity levels are unknown. We tested to see if high-intensity (i.e., 85 dBnHL) iChirp stimulation results in larger and more reliable ABR wa...

Immunocellular mechanisms that account for the association between psychosocial risk factors and increased susceptibility to faster progression of HIV/AIDS are largely unknown. This study used structural equation modeling to test the hypothesis that enumerative and functional alterations in killer lymphocytes mediate the relationship between higher levels of psychological distress (defined by p...

Dietary restriction (DR) started in middle age profoundly reduces the occurrence of lymphoma in C57BL/6 mice. Here, we report immunocellular and molecular changes associated with this mode of cancer prevention. Twelve-month-old male C57BL/6 mice were either fed a control diet or subjected to moderate DR (approximately 25% < control intake). DR significantly reduced lymphoma development (inciden...