Unilateral Versus Bilateral Hearing Aid Fittings

Fitting a Hearing Aid on the Better Ear, Worse Ear, or Both: Associations of Hearing-aid Fitting Laterality with Outcomes in a Large Sample of US Veterans

“…Our observation that unilateral fittings became more common with increased hearing asymmetry is in line with the findings of Boymans and Dreschler (2011). They reported that the average hearing asymmetry for unilateral fittings was 22 dB, while for bilateral fittings it was 8 dB.…”

“…Bilateral and better-ear fittings have similar long-term outcomes, but short-term outcomes being poorer for better-ear than bilateral fittings. Our findings thus provide strong empirical evidence for the recommendation made by others (e.g., Boymans & Dreschler, 2011;Dillon, 2012;Glyde et al, 2021;Kiessling et al, 2006;Noble & Gatehouse, 2006) that HAs should be fitted bilaterally under almost all circumstances. We also note that HAs today can offer even more advanced technological features compared to what is available with the HAs provided to our sample of patients.…”

“…A patient looking for ease of use might also be more likely to stop using their device than someone who is prioritizing their hearing ability. However, many studies have demonstrated the advantages of bilateral fittings (e.g., Boymans & Dreschler, 2011;Dillon, 2012;Noble & Gatehouse, 2006;) and it is therefore plausible that a higher degree of satisfaction and clearer benefits will lead to more persistent HA use. In addition, the observation that persistence rates for better-ear fittings were significantly higher than those for worse-ear fittings points toward a causal influence of laterality on long-term HA usage.…”

“…Similarly, several smaller-scale studies also showed better outcomes with bilateral than unilateral fittings. Specifically, in a prospective study of 214 participants, Boymans and Dreschler (2011) found bilateral fittings superior in terms of the users’ localization ability and speech understanding and concluded that “the benefit of a second HA is obvious” (p. 294). They recommended that “every hearing-impaired subject should start with a bilateral fitting to experience the benefits and the drawbacks” (p. 294).…”

“…Reasons given for this choice include cost, age (with older individuals performing better in noise with a unilateral fitting), binaural interference, decreased occlusion, and the reduced effort of handling a single device ( Henkin et al, 2007 ; Jespersen et al, 2006 ; Schilder et al, 2017 ; Walden & Walden, 2005 ). Furthermore, unilateral fittings are sometimes considered advantageous when it comes to the use of telephones or when the capacity of the unaided ear is “relatively good […] or just worse” ( Boymans & Dreschler, 2011 , p. 286).…”