Individual factors underlying preference for processing delay in open-fit hearing aids

In open-fit hearing aids (HAs), the processing delay determines the magnitude of the comb-filter effect that arises from the interaction between the processed and direct sound. It is thus an essential factor for HA sound quality. Research has shown clear individual differences in preferred processing delay. The aim of the current study was to investigate if basic spectral and temporal processing abilities and self-reported listening habits can explain these differences. Groups of listeners with normal hearing or mild-to-moderate sensorineural hearing loss participated. Temporal and spectral processing abilities were assessed using gap detection threshold and spectral ripple discrimination measurements. Personal listening habits were assessed using a subscale of the ‘Sound Preference and Hearing Habits Questionnaire’ (SP-HHQ). Preference for processing delay was assessed using a realistic HA simulator and a pairwise comparison task. Several processing delays in the 0-10 ms range were tested. We hypothesize that individuals with good temporal and spectral processing abilities will prefer shorter processing delays. We also hypothesize that individuals who score higher on questionnaire items related to ‘Importance of Sound Quality’ will prefer shorter processing delays. Overall, we expect that our results will provide insights into more personalized HA solutions.