(PP316) Subjective and Objective Evaluation of the Telecoil in Ecological and Laboratory Environments

Abstract: There are numerous wireless assistive listening technology options available to hearing aid wearers, such as remote microphones, smartphone streaming, hearing loops and neck loops. It is important for clinicians to understand the relative efficacy of these systems. We conducted a series of experiments comparing the standard hearing aid microphone configuration to wirelessly delivered audio, among BTE and CIC hearing aid users. We conducted lab-based speech recognition tests and ran a field study that culminated in a simulated movie theater/auditorium listening experience for user-behavior observation. Participants also provided subjective ratings of the listening modes for different types of audio.

Summary: There are numerous wireless assistive listening technology options available to hearing aid wearers, such as remote microphones, smartphone audio streaming, induction hearing loops, neck loops, and others. It is important for clinicians to understand the relative efficacy of these systems as well as their patients’ understanding of and attitudes towards using them.

Previous research found functional equivalence between FM systems and proprietary remote microphone transmission protocols (Rodemerk and Galster, 2015). However, certain assistive listening devices may not be suitable for use in all social situations. For example, remote microphones may not be appropriate in large groups, where public address systems are already in use. Kochkin et al., (2014) previously reported that a majority of hearing aid users indicated preference for using telecoil-equipped hearing aids rather than the FM or infrared broadcast systems that are often provided in large venues.

We conducted a series of experiments comparing the standard hearing aid microphone configuration to wirelessly delivered audio, among two diverse patient groups: behind-the-ear (BTE) hearing aid users (n=14) and completely-in-the-canal (CIC) hearing aid users (n=14). In particular, we conducted speech recognition tests comparing hearing aid users’ performance with standard hearing aid microphone configurations to that with a proprietary remote microphone system, a hearing loop system using the telecoil function, and a smartphone audio streaming application.

In addition, we conducted a field trial of hearing aids that concluded with a simulated movie theater and auditorium listening experience. At the time of initial hearing aid fittings, a subset of the participants was provided with an orientation and demonstration of the hearing loop and telecoil functionality. When the participants (n=28) returned, two months later, for the simulated movie theater and auditorium visit, we made observation of which participants utilized their hearing loop hearing aid setting. We also probed the participants regarding the presence or absence of hearing accessibility signage at the entrance to the auditorium used for the simulation. Findings from these observations underscore the importance of counseling and in-office demonstration of assistive listening devices.

During the simulated movie theater and auditorium listening experience, participants (n=28) also provided subjective rating comparisons of the standard hearing aid microphone configuration and a hearing loop setting. For these comparisons, BTE hearing aid users (n=14) utilized the embedded telecoil of the hearing aids, while the CIC hearing aid users (n=14) accessed the hearing loop with an external telecoil included in a multifunction, wireless hearing aid accessory. The participants rated each of the listening modes for different types of audio of interest, including live speech, British film, American film, symphonic music, and music with vocals.