Considerations for users of Hearing Aids and Cochlear Implants
Stimulus-device compatibility (from Stimulus page)
Earphones are generally not an option for aided listening. If a participant’s audiogram is known in advance stimuli presented through earphones can be amplified to improve audibility when listening without hearing aids. The experimenter should take care to check that amplification does not produce uncomfortably loud stimuli. Participants with hearing aids that fit entirely in the ear canal may be able to use their hearing aids while listening through earphones, although this should be tested to check for undesired physical or acoustic interactions between the earphone and the hearing aid. Loudspeaker presentation is an option for aided listening, although the experimenter should take care to ensure that participants are oriented relative to the loudspeaker to avoid confounding differences in hearing aid directionality. Some hearing aids also have streaming capabilities through Bluetooth, which could enable a direct connection from a computer to the hearing aid. It may be helpful to obtain permission from participants to contact their audiologists for information on how the device is programmed, as various settings (noise reduction algorithms, directional microphones, compression) will alter how acoustic stimuli are processed across individuals.
Similar to hearing aids, headphones do not provide good aided listening to participants with cochlear implants. However, there are published studies that used circumaural headphones to present stimuli (Grantham et al., 2008andGoupell et al., 2018). Loudspeaker presentation is an option, and some cochlear implants have direct connection audio jacks and/or Bluetooth streaming capabilities. Implants tend to process a narrower frequency range than acoustic hearing, so at-home audio devices (e.g. laptop speakers) may have a sufficient frequency response in the range that the cochlear implant processes, but this should be experimentally verified.
The advice for hearing aids and cochlear implants may generalize to other assistive devices (e.g. bone-anchored hearing aids, auditory brainstem implants), but it is up to the experimenter to determine whether stimuli are being heard as intended. If you have experience with remote testing specific devices please share your advice here.
Verification of device function and configuration
Depending on the manufacturers, hearing-aid and cochlear implant users may have additional accessories to view and toggle between programs stored on their devices, which includes brief descriptions of the front-end features activated for each program. However, most detailed fitting information (e.g., threshold/comfortable levels, frequency-to-electrode allocation, de-activated electrodes) is only accessible through the programming interface. If the detailed fitting information is necessary for determining the device function and how it will alter acoustic stimuli for the study, the experimenter may want to connect with the patient’s audiologist ahead of time to obtain a detailed device fitting report. If logistics allow for a clinical visit before study participation, the experimenter can also work with the participant to suggest certain features to be fitted in a designated program in the device and have additional measures performed (e.g., free-field threshold) with the audiologist as part of the visit. Alternatively, the experimenter can also consider remote device fitting as part of the study protocol to obtain device fitting information (below for an example about remote CI fitting).
Remote device fitting
A component of some telehealth activities, as well as some commercial platforms for remote testing in audiology, is the ability to verify and/or adjust clinical devices remotely. For an example, see Remote Cochlear Implant Programming Protocol – Western Washington University