John C Ellison

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Stimulus frequency otoacoustic emission (SFOAE) sound pressure level (SPL) and latency were measured at probe frequencies from 500 to 4000 Hz and probe levels from 40 to 70 dB SPL in 16 normal-hearing adult ears. The main goal was to use SFOAE latency estimates to better understand possible source mechanisms such as linear coherent reflection, nonlinear(More)
Stimulus frequency otoacoustic emissions (SFOAEs) measured using a suppressor tone in human ears are analogous to two-tone suppression responses measured mechanically and neurally in mammalian cochleae. SFOAE suppression was measured in 24 normal-hearing adults at octave frequencies (f(p)=0.5-8.0 kHz) over a 40 dB range of probe levels (L(p)). Suppressor(More)
Relationships between click-evoked otoacoustic emissions (CEOAEs) and behavioral thresholds have not been explored above 5 kHz due to limitations in CEOAE measurement procedures. New techniques were used to measure behavioral thresholds and CEOAEs up to 16 kHz. A long cylindrical tube of 8 mm diameter, serving as a reflectionless termination, was used to(More)
The goals of the current study were to: 1) evaluate the feasibility of a new wideband approach to measuring middle-ear muscle reflex (MEMR) status, and 2) to test the hypothesis that ipsilateral thresholds elicited with 1 or 2 kHz tones and broadband noise activators on a wideband acoustic transfer function (WATF) system are lower than thresholds elicited(More)
OBJECTIVE The goals of the study are to determine how well stimulus-frequency otoacoustic emissions (SFOAEs) identify hearing loss, classify hearing loss as mild or moderate-severe, and correlate with pure-tone thresholds in a population of adults with normal middle ear function. Other goals are to determine if middle ear function as assessed by wideband(More)
Behavioral threshold for a tone burst presented in a long-duration noise masker decreases as the onset of the tone burst is delayed relative to masker onset. The threshold difference between detection of early- and late-onset tone bursts is called overshoot. Although the underlying mechanisms are unclear, one hypothesis is that overshoot occurs due to(More)
In contrast to clinical click-evoked otoacoustic emission (CEOAE) tests that are inaccurate above 4-5 kHz, a research procedure measured CEOAEs up to 16 kHz in 446 ears and predicted the presence/absence of a sensorineural hearing loss. The behavioral threshold test that served as a reference to evaluate CEOAE test accuracy used a yes-no task in a(More)
The effects of the interaction of compression release time and prescribed gain on running speech processed through a hearing aid on KEMAR was investigated. A digital instrument was programmed to fit a mild to moderate sloping hearing loss using probe microphone measures to reach targets prescribed by NAL-NL1, DSL I/O, FIG.6 or ASA2p with release times of 40(More)
A system with potential for middle-ear screening and diagnostic testing was developed for the measurement of wideband energy absorbance (EA) in the ear canal as a function of air pressure, and tested on adults with normal hearing. Using a click stimulus, the EA was measured at 60 frequencies between 0.226 and 8 kHz. Ambient-pressure results were similar to(More)
OBJECTIVES/HYPOTHESIS Compare the accuracy of wideband acoustic transfer functions (WATFs) measured in the ear canal at ambient pressure to methods currently recommended by clinical guidelines for predicting middle-ear effusion (MEE). STUDY DESIGN Cross-sectional validating diagnostic study among young children with and without MEE to investigate the(More)