RP213 - Cognitive Outcomes Following Linear and Non-Linear Amplification

Thursday, April 20, 2023

5:15 PM – 5:45 PM PDT

Location: Rooms 608-609 ** 705 Pike

Earn 0.05 CEUs

Lead Presenter(s)

Grant D. Searchfield, PhD (he/him/his)

Academic Head
Audiology the University of Auckland
The University of Auckland
Auckland, New Zealand

Disclosure(s): Oticon: Other Research Support (Ongoing); TrueSilence: Intellectual Property/Patents (Ongoing), Ownership Interest (Ongoing), Patent Holder (Ongoing), Royalties (Ongoing)

PDF Slides

Contributor(s)

MM

Megan McAuliffe

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
CF

Christine Fok

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
TA

Tin Aung Kyaw

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Lisa J. Burton-Harris, Masters of Neuroscience KCL

Doctoral Candidate
The University of Auckland
The University of Auckland

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
GC

Gavin Coad

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
AS

Alice H. Smith, AuD (she/her/hers)

Clinic Director
University of Auckland Audiology Teaching Clinic
University Of Auckland Clinics | Audiology Teaching Clinic | Audiology Section of School of Population Health
Grafton, Auckland, New Zealand

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
DV

Dunja Vajsakovic

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

Contributor (Not Presenting)(s)

EW

Eric Williams, PhD (he/him/his)

University of Canterbury, New Zealand

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

Abstract:
This double-blind multiple-site randomized-controlled trial tested the hypothesis that a Simple (linear-based) hearing aid fitting strategy would improve hearing and cognition more than a Standard (compression-based) strategy in adults over 65 years old with below average fluid cognition. Both hearing aid groups improved on measures of fluid cognition and hearing. There was a statistically significant difference in fluid cognition between groups at 12 months. Per-protocol participants receiving the Simple fitting improved their NIH fluid cognition composite score by 4-points those with the Standard fitting improved by 11-points. Hearing aids improved cognitive performance, but the Standard fittings showed the greatest improvement.

Summary:
Rationale
Untreated hearing loss appears to speed up age-related decline in cognition so hearing aids have been proposed to slow age-related cognitive decline. However, the long-term benefits of hearing aids on cognition are uncertain. It was hypothesized that simpler hearing aid processing would offer significant long-term benefits over standard hearing aid settings for hearing and cognition for persons with slower cognitive processing. This double-blind multiple site randomized controlled trial tested the hypothesis that a Simple (linear-based) hearing aid fitting strategy would improve hearing and cognition more than a Standard (compression-based) strategy in adults over 65 years old with below average fluid cognition.

Methods: Two-hundred and fifty six adults aged over 65 were screened for cognitive function using the NIH toolbox cognitive battery. Participants with below median scores on age adjust fluid composite cognitive score ( < 100) were eligible to participate (n=104). Sixty-six of the eligible participants proceeded to the trial and were randomized 1:1 to a simple (NAL-R based prescription) or standard (NAL-NL2 based prescription) hearing aid fitting. Participants and researchers not fitting the hearing aids were blinded to allocation.

Results: Forty-eight participants completed all assessments to 12 months. Both hearing aid groups improved on measures of fluid cognition and hearing. There was a statistically significant difference in fluid cognition between groups at 12 months. Per-protocol participants receiving the Simple fitting improved their fluid cognition composite score by 4 points those with the Standard fitting improved by 11 points. There were no statistically significant differences between groups for crystallized cognition scores, Word-In-Noise test and hearing questionnaire outcomes. Datalogging indicated equal hours of use for the two groups.

Conclusion
Hearing aids improved cognitive performance, but the Standard fittings showed the greatest improvement. The greater benefit of the Standard fitting over the Simple fitting was the opposite from that hypothesized. This is the first study to show that different hearing aid fitting strategies can impact chronic cognitive outcomes. These results have important ramifications for hearing healthcare delivery. The results reinforce findings indicating hearing aid benefits for the elderly and that the nature of amplification can significantly affect cognitive outcomes. The different cognitive outcomes with equivalent improvement in hearing suggest that the mechanisms underlying benefit in cognition from hearing aids is through a stimulation mechanism and reduced auditory deprivation, rather than solely through improved socialisation. Selection of amplification can have a strong impact on cognitive outcomes. Until the risks and long-term benefits of amplification on cognition are ascertained clinicians should be involved in providing hearing aids and monitoring their outcomes.

Learning Objectives:

Describe the study design.
Interpret cognitive and hearing outcomes in a population with mild cognitive impairment.
Apply the study recommendations for dispensing hearing aids in a population with mild cognitive impairment.