Effects of earlens lens placement on sound field thresholds, tympanometric measurements and wideband acoustic immittance

Abstract

Objective

The Earlens is a direct-drive hearing device consisting of a lens which physically displaces the umbo to achieve appropriate gain. The objective is to determine the clinical acceptability of clinical immittance measurements in Earlens wearers.

Design

Controlled before-after within-subjects repeated measures study.

Study sample

Data is reported for measurements obtained on 15 subjects (average age of 72.2 years) with data from 30 ears.

Results

There was a small effect of lens placement on sound field thresholds in most subjects. The largest damping effect of 4 dB was observed at 1000 Hz. An average reduction of 0.17 mL was identified in compliance following lens placement (p < 0.05). An effect of the lens on power absorbance obtained at ambient and peak pressure was found. The lens resulted in an increase in power absorbance at low frequencies (below 500 Hz) and a decrease in the mid to high-frequency range of approximately 500–3500 Hz (p < 0.05).

Conclusions

Lens wear had a small effect on audiometric thresholds and tympanometry for most patients. Clinicians who use compliance and power absorbance should take into consideration lens effects on these measurements. Additional work is required to develop clinical normative ranges of these measures for wearers of the Earlens.

Keywords:

• Earlens
• tympanic membrane
• wideband acoustic immittance
• tympanometry
• power absorbance
• direct drive hearing aid

Acknowledgements

The authors thank Tanya Arbogast, Sandy Wanner, Parvaneh Abbasalipour, Rana El-Naji and Frances Richert, for their assistance with hearing device fittings, Judy Brimacombe for logistical support, and Steve Beaulac for technical support. We also thank Bilal Sheikh and Nicole Willis for their work on the project as lab members of the Translational Research Unit, as well as Matthew Urichuk, Lauren Siegel and Sunil Puria for manuscript review.

Disclosure statement

Drew Dundas and Suzanne Levy are employees of Earlens Corporation. No conflicts were declared for the remaining authors.

Additional information

Funding

The National Centre for Audiology received funding from Earlens Corporation for the direct costs of this study. Susan Scollie is a member of the audiology advisory board for Earlens Corporation.