Performance at different stimulus intensities with the within- and across-channel adaptive tests of temporal resolution.

OBJECTIVE: The Adaptive Tests of Temporal Resolution (ATTR©) software provides within-channel (WC) and across-channel (AC) adaptive measures of temporal resolution that are feasible for clinical applications. The purpose of the present study was to obtain normative values for young adults on two of the ATTR tests: the narrow-band noise within-channel (NBN-WC) test and the narrow-band noise across-channel (NBN-AC) test, at different stimulus intensities. DESIGN: Gap detection thresholds were measured at five sensation levels. A Latin square design was used to control for practice effects. STUDY SAMPLE: The NBN-WC group and the NBN-AC group each consisted of 25 young adults with normal hearing. RESULTS: Gap detection thresholds for both conditions decreased with increasing stimulus intensity, and stimulus intensities above 20 dB SL were not associated with large improvements in performance. Variability was larger in the NBN-AC condition. Values obtained for the NBC-WC condition were very similar to previously reported ATTR results despite equipment and design differences. CONCLUSION: Results provide normative values for NBN-WC and NBN-AC performance on the ATTR and suggest that the ATTR is a robust test for clinical use.

Evaluation of otoacoustic emissions in clinically normal alert puppies.

OBJECTIVE: To evaluate distortion product otoacoustic emission (DPOAE) measurements in puppies with normal hearing. ANIMALS: 23 clinically normal 7.5-to 10.5-week-old puppies. PROCEDURES: A cross-sectional study was performed. The DPOAE measurements were obtained with a commercially available distortion product otoacoustic measurement system and were performed in a quiet, non-sound-attenuated room. All measurements were obtained from alert puppies and were repeated 1 or 2 times to ensure that the measurements were replicable. Results that were a minimum of 8 dB higher than the noise floor were accepted. Values from the first trial in which emissions were obtained at all test frequencies were used for analysis. RESULTS: Otoacoustic emission measurements were easily obtained, robust, reliable, and consistent with auditory brainstem response and behavioral results. CONCLUSIONS AND CLINICAL RELEVANCE: Hearing screening in alert puppies can be accomplished reliably and rapidly with otoacoustic emissions testing. Results supported the possibility of the use of DPOAE measurement in hearing screening of dogs.