Hearing Aid Acclimatization
Many clinicians are concerned with the time and benefits of hearing aid amplification and acclimatization. Humes et al (2002) reported the results of 134 people fitted with hearing aids at one month, 6 months and 12 months post fitting; and 49 of these people were followed for a total of 24 months. They reported that overall there was very little evidence to support acclimatization of hearing aid benefit, based on group or individual data. Likewise, Saunders and Cienkowski (1997) reported on 24 new and 24 experienced hearing aid users, with data collected at 30, 60, and 90 days post-fitting and reported that "the clinical ramifications of acclimatization are probably small." Taylor (2007) reviewed the peer-reviewed literature on acclimatization and concluded "…the average length of time a patient may require to become accustomed to their hearing aids, regardless of user history, is approximately 30 days."
Tremblay and Moore (2012) report that auditory rehabilitation is to a large degree dependent on the brain’s capacity to change once an audible signal is presented to the brain. After audibility has been accomplished, "task-oriented and repetitive training" facilitates the brain’s ability to use the sound maximally. Unfortunately, many professionals do not engage in "task-oriented and repetitive training" and as a result, maximal performance is not always obtained. Tremblay and Moore define "plasticity" as the capacity for neural change (in structure and/or function), resulting from sensory experience. The authors note that people with the same type and degree of hearing loss often perform quite differently with regard to understanding speech—even while using the same/similar hearing aids. They note the degree of benefit obtained depends in part on the patients age and their individual response to auditory deprivation and stimulation. That is, people who do not do well with hearing aids (and/or cochlear implants) may have auditory systems that are "less plastic" (less capable of representing new acoustic cues). Of significant importance, Tremblay and Moore essentially state with regard to hearing aid fittings and acclimatization, in the absence of targeted therapy over time (i.e., auditory training) "perceptual changes previously thought to reflect neuroplastic processes resulting from hearing aid use have since been attributed to changes in audibility related to hearing aid gain."
For More Information, References, and Recommendations
Humes LE, Wilson DL, Barlow NN, Garner C. (2002) Changes in Hearing Aid Benefit Following One or Two Years of Hearing-Aid Use by Older Adults. Journal of Speech, Language, and Hearing Research 45(8):772-782.
Saunders G, Cienkowski KM. (1997) Acclimatization to Hearing Aids. Ear & Hearing 18(2):129-139.
Tremblay, K. and Moore, D (2012): Current Issues in Auditory Plasticity and Auditory Training. In Translational Perspectives in Auditory Neuroscience. Editors: Tremblay KE, Burkard RF, Plural Publishing.