PP313 - Assessing Distortion in Modified Listening Scope Solutions for Deaf Audiologists

Abstract:
Modified-listening-scopes were evaluated to address the challenges of traditional hearing aid and assistive listening device checks; these procedures are not accessible to deaf audiologists. Also investigated was the impact of hearing aid characteristics (prescribed gain, technology level, and manufacturer) on output fidelity when using six modified listening scopes via a measure of distortion. Results were analyzed through a reliability measure to establish internal consistency and agreement between measurements. Findings are useful to those who leverage modified-listening-scopes to perform hearing device checks, and to the individuals with whom they interact, and add to the developing literature in this domain.

Summary:
In a survey of deaf audiologists and audiology students, hearing aid and assistive listening device checks were cited with the highest difficulty of procedures to perform (Yoder & Pratt, 2005). Traditional listening scopes are not accessible to deaf audiologists. Without accommodation or specialized equipment, it can be difficult to assess distortion, perceive quiet feedback, and perceive low-gain hearing aids (Allen et al., 2002; Bethel & Mormer, 2020). While it is positive that deaf audiologists can leverage these various solutions, there is scant peer-reviewed evidence to support the use of any given modified listening scope, be it experiential or quantifiable, or about how to alleviate these limitations posed by each modification. Most discussion has anecdotally occurred in online forums, but one assessment of deaf audiology students revealed many identify solutions themselves, or with instructors; fewer identify solutions via their audiology programs or from professional conferences and organizations (Bethel & Mormer, 2020). 

The purpose of this study is to assess modified-listening-scope solutions to provide stakeholders with considerations when selecting which modification might be individually appropriate and effective. These stakeholders include deaf audiologists and students, as well as other deaf professionals and caretakers who require means for the performance of a modified listening check. Additionally, this information will be important to those who work alongside deaf audiology students and audiologists, such as preceptors and coworkers, as well as for audiologists to provide their patients who work clinically. 

The following research questions will be explored:

1. How does the prescribed gain, technology level, or manufacturer of a hearing aid being listened to affect output through a modified listening scope? 
2. Does any modified listening scope best maintain the signal fidelity of a hearing aid being listened to depending on a given characteristic?

This study will assess the signal fidelity of a hearing aid through a modified listening scope attached to a hearing aid representing the listener’s hearing aid, which remains constant for all conditions. Eight research conditions undergo six test conditions measuring distortion. Each research condition is a hearing aid prescribed with one characteristic from each category: prescribed gain (soft or loud), technology level (low-end or high-end), and manufacturer (Oticon or ReSound). The test conditions are defined as the various listening scopes: traditional-monaural-listening-scope, bluetooth-microphone-based-modified-scope, digital-modulation-system-based-modified-scope, earmold-over-microphone-modified-scope, and telecoil-based-modified-scope, and a no-scope condition to establish a baseline for each device.

Signal fidelity will be measured through a distortion analysis performed in the Verifit2 test box. Analysis of the results will include a reliability measure, such as the intraclass correlation coefficient, to convey the internal consistency of the novel measurements taken in this study per hearing aid per listening-scope, and their agreement across multiple runs. Findings will be useful to those who might benefit from modified listening scopes to perform hearing aid and assistive listening device checks, and to those who interact with individuals who do. This research will contribute to the limited literature about which modified listening scopes are effective and serve as a foundation for future work in this critical area. The research will be completed before February 2024.