Localization of low frequency noise with hearing aids (HAs) and personal sound amplification products (PSAPs)

Abstract

This purpose of this study was to evaluate the performance of hearing aid (HA) and personal sound amplification products (PSAPs) in adverse listening environments, such as those with background noise. Specifically, the unaided speech identification and localization ability of twenty-five participants with hearing loss were analyzed using a 13-speaker array. Two of these participants completed additional testing in aided conditions: one with an Oticon Nera MiniRITE Hearing Aid and one with a CS 50+ Personal Sound Amplification Product. Speech identification thresholds were found for each participant using Coordinate Response Measure (CRM) corpus. Data obtained from speech identification testing was compared between co-located and separated conditions. Localization ability was assessed using percent accuracy and root-mean-square (RMS) error for low frequency noise and broadband noise. Participants unaided speech identification results indicated that participants with hearing loss receive spatial release from masking when the target and masker are separated, which was consistent with previous studies (Collins, 2019; Connaster, 2018; Srinivasan, 2016). Unaided localization indicated a higher percent accuracy and lower RMS error for the broadband noise test condition compared to the low frequency noise. This result demonstrates that when participants can utilize both ITD and ILD cues, rather than primarily ITD cues, their performance is better. These results were consistent with previous studies (Dobreva, O’Neill, & Paige, 2011; Van den Bogart, 2006). Participants aided speech identification results were reported within subject, as the sample size was small (n = 2). Participant 1 (MH) did not demonstrate any significant release from masking across any condition, whereas Participant 2 (TM) received a significant spatial release from masking in the unaided condition and the hearing aid condition. In the current study, aided results from the two qualifying participants revealed the highest percent accuracy and lowest RMS error in the hearing aid condition. These results are consistent with data from Collins (2019) study but are not consistent with studies with more participants (Connaster, 2018; Van den Bogart, 2006). It is likely that with more participants and repetition of all tasks, aided findings would align more with the literature. Continued study into PSAP devices and performance in adverse listening environments is crucial for the communicative success of our patients.