Assessing Distortion in Modified Listening Scopes for Deaf Audiologists.

Purpose: The use of traditional (i.e., unmodified) listening scopes for hearing aid and assistive listening device checks is not practically accessible for all clinicians; such is the case for deaf audiologists. Despite the need, there is a paucity of evidence-based information regarding modified listening scopes. The focus of this investigation was to evaluate the output clarity through various modified listening scopes via a measure of distortion. The impact of hearing aid type on measurements was also preliminarily analyzed. Method: Eight test hearing aids were measured under seven listening scope conditions. A distortion analysis was performed for each setup across 13 frequencies from 250 through 4000 Hz on the Verifit2. Data were analyzed using repeatedmeasures analysis of variance with within-subject factors to establish internal consistency and agreement between measurements and identify any main effects. Results: Significant main effects of listening scope condition and frequency were observed. There were no effects of trials, suggesting data homogeneity and that hearing aid type did not impact measures. Post hoc analyses indicated that the modified scope utilizing Bluetooth technology generated the most significant distortion in the output of the tested hearing aid. Conversely, distortion from other scopes seems clinically negligible. Conclusion: The findings regarding output clarity of various modified listening scopes have clinical applications for those professionals who find traditional listening scopes practically inaccessible and seek to make evidence-based decisions about using modifications.