Does experience with hearing aid amplification influence electrophysiological measures of speech comprehension?

Abstract

Objective

To explore if experience with hearing aid (HA) amplification affects speech-evoked cortical potentials reflecting comprehension abilities.

Design

N400 and late positive complex (LPC) responses as well as behavioural response times to congruent and incongruent digit triplets were measured. The digits were presented against stationary speech-shaped noise 10 dB above individually measured speech recognition thresholds. Stimulus presentation was either acoustic (digits 1-3) or first visual (digits 1-2) and then acoustic (digit 3).

Study sample

Three groups of older participants (N = 3 × 15) with (1) pure-tone average hearing thresholds <25 dB HL from 500-4000 Hz, (2) mild-to-moderate sensorineural hearing loss (SNHL) but no prior HA experience, and (3) mild-to-moderate SNHL and >2 years of HA experience. Groups 2-3 were fitted with test devices in accordance with clinical gain targets.

Results

No group differences were found in the electrophysiological data. N400 amplitudes were larger and LPC latencies shorter with acoustic presentation. For group 1, behavioural response times were shorter with visual-then-acoustic presentation.

Conclusion

When speech audibility is ensured, comprehension-related electrophysiological responses appear intact in individuals with mild-to-moderate SNHL, regardless of prior experience with amplified sound. Further research into the effects of audibility versus acclimatisation-related neurophysiological changes is warranted.

Keywords:

• Speech perception
• hearing loss
• hearing aids
• plasticity
• cortical evoked potentials

Acknowledgments

The authors thank Amalie Tage Stubberup (Dept. of Audiology, Odense University Hospital) as well as Stine Christiansen and Ågot Møller Grøntved (Institute of Clinical Research, University of Southern Denmark) for help with participant recruitment.

Disclosure statement

The authors declare no potential conflicts of interest concerning the research, authorship, and publication of this article.

Additional information

Funding

This research was funded by a Ph.D. stipend from the Institute of Clinical Research, University of Southern Denmark.