Nov 2020 The Hearing Journal
As audiology explores interventions that patients can self-direct with minimal help from clinicians, self-fitting hearing aids show the potential to be an accessible and cost-effective solution for individuals with hearing loss. However, unlike conventional hearing aids, self-fitting hearing devices have to be set up by the users themselves, which means successfully fitting them depends on a layperson's ability. A study from the National Acoustic Laboratories in Australia examined a device's setup procedures to identify factors associated with successful self-fitting of commercial hearing aids. It found that non-audiologic factors, such as the user's characteristics and access to supporting resources, should be considered when audiologists identify candidates for self-fitting hearing devices.
CHARACTERISTICS OF IDEAL CANDIDATES
The study tested the setup of Companion self-fitting hearing aid manufactured by Sound-World Solutions. This device came with a mobile app for users to perform in situ measurement of pure-tone hearing thresholds. To complete the self-fitting procedure, 60 participants aged 51 to 85 had to customise the hearing aid's physical fit, insert the device into their ear, conduct self-directed in situ audiometry, and adjust the settings according to their preference. A trained clinical assistant was available to provide support at any point in the process. The researchers found that “ successful self-fitting arises from the interaction between the personal characteristics of the user and the resources that are available to support the performance of the task.”
But what characteristics would be ideal for a candidate for this type of hearing aid? The paper suggested that “previous experience with hearing aids and previous experiences with mobile devices, such as smartphones and tablets, were the two most important personal factors that influenced the likelihood of a successful self-fitting.” This “could be related to the major role the app played in the self-fitting process.”
The significance of previous experience may pose a challenge because smartphone penetration among older adults, who are the main demographic for hearing aid use, “lags behind that of other age groups.” Age was also identified as a general barrier to technology adoption. As such, the researchers underscored the need for hearing aid manufacturers to ensure that their products can be efficiently used even by older adults who lack experience with mobile apps. “While it could be argued that this problem will diminish in the future as those who are currently familiar with smartphones grow older, it is very likely that subsequent introduction of newer technology will continue to challenge the older population,” the paper posited.
A user's health locus of control was also found to factor in successful hearing aid self-fitting.
“‘Health locus of control’ refers to a person's perceived source of control over their lives within a health context,” explained lead researcher Elizabeth Convery. “Health locus of control may be more internally oriented, meaning that the person believes they are personally responsible for—and in control of—their own health outcomes, or it may be more externally oriented, meaning that the person believes that outside factors have the greatest impact on their health outcomes.”
Further, a person “may be externally oriented toward ‘chance’, whereby they believe that their health depends largely on luck or fate. Alternatively, a person may be externally oriented toward ‘powerful others; meaning that they believe their health outcomes are largely in the hands of those they perceive as ‘powerful’, which, in a healthcare setting, typically means healthcare professionals. In our self-fitting study, we found that it was this latter group, those with an external orientation toward ‘powerful others’, who were more likely to seek help with the self-fitting process from the designated support person,” said Convery.
QUALITY OF INSTRUCTIONAL RESOURCES
The quality of hearing aid user guides can also influence the usability of the product, stressed the researchers. In this study, self-fitting instructions were shown in a video on a laptop, leading to 78 percent of the participants inserting the hearing aid correctly without assistance. The researchers believed that in the future, video instructions can be feasibly incorporated into the hearing aid mobile app itself. The study also noted that the majority of successful self-fitters had personalised support from clinical assistants. “Although computer-based instructions and video clips were shown to improve self-fitting skill acquisition relative to past studies in which printed instruction booklets were used, the majority of people are still likely to require access to support from trained personnel while carrying out the self-fitting procedure, especially when this requires the use of an app,” the authors concluded.
KEY COMPONENTS OF SELF-FITTING
Given the findings of their study, Convery shared some important components of what might be a viable service delivery model for self-fitting hearing aids:
- Online assessment of hearing needs to determine candidacy for self-fitting
- Appealing hearing aid design; app interface optimised for older users
- Multimedia instructions based on best-practice health literacy principles
- On-going support accessible anytime anywhere, plus behavioural ‘nudges’ to encourage a user to seek support
- Addressing psychosocial needs via Skype sessions with hearing health care professionals.
Convery cautions, however, that their study used only one specific brand and model of hearing aid; their results have not been universally tested. But the paper does offer a recommendation that may be widely noted by researchers and manufacturers:
“To be viable, a delivery model would need to ensure that relevant predictive factors—which may not be part of the standard audiologic test battery—are appropriately assessed and that access to trained personnel is available to provide on-demand support to patients at every stage of the self-fitting procedure.”