No Effect of Interstimulus Interval on Acoustic Reflex Thresholds

Presence of ipsilateral acoustic reflex artifact may result in clinical misidentification

OBJECTIVE

Upon calibration of a specific commercially available immittance device, an artifact was consistently measured in a calibration cavity when in ipsilateral acoustic reflex mode. These results were replicated in a controlled fashion, raising concerns about how clinical results might potentially be misinterpreted.

DESIGN

Responses were measured from an Interacoustics Titan and Grason-Stadler Tympstar Pro immittance device coupled to a 0.2 cc and, separately, to a 1.0 cc calibration cavity when in ipsilateral acoustic reflex mode. The procedure was repeated with the same outcomes.

RESULTS

Clinically significant responses ordinarily associated with presence of an ipsilateral acoustic reflex were obtained in a 0.2 cc and 1 cc coupler with stimuli presented at 0.5 kHz, 1 kHz, and 2 kHz with one of the Interacoustics Titan, but were not obtained in the same conditions with the Grason-Stadler Tympstar Pro.

CONCLUSIONS

A commercially available immittance device yielded clinically-significant responses to ipsilateral acoustic reflex stimuli within calibration cavities of various sizes. Results suggest that false-positive responses may be obtained when certain immittance devices are used clinically, producing possible misleading or incorrect clinical impressions and assessment.

ManCAD100: 100 Years of Audiology and Deaf Education at Manchester

In 2019, the Manchester Centre for Audiology and Deafness celebrates its 100th anniversary. To mark the centenary, this special issue is a collection of papers that showcases current research in Manchester Centre for Audiology and Deafness. The Editorial provides a brief history and description of the Centre and an overview of the special issue.