Advances in earmold technology: one-stage (direct) approach.
Many hearing aid users require a customized earmold. When the hearing impairment is severe or profound, it is essential that a good fit of the earmold is achieved to avoid leakage of sound and acoustic feedback (whistling) so that the full potential of the hearing aid can be achieved. Existing laboratory technology for the production of earmolds by a two-stage process leads to dimensional inaccuracy because of (1) unsuitable materials that shrink and (2) techniques used to achieve a surface finish. Recently, a novel soft material, from which an accurate earmold can be fabricated by a one-stage process directly in the ear, has been invented by the author and patented by the United Kingdom Department of Health. This paper describes the new technology, which could provide very significant benefits in the rapid fabrication of accurate earmolds without requiring sophisticated laboratory facilities. In addition, important implications for very young infants, the profoundly deaf, and for earmold use in developing countries will be discussed.
Okpojo
A O
AO
Centre for Audiology, Education of the Deaf and Speech Pathology, University of Manchester, UK.
D012048:Correction of Hearing Impairment; D004867:Equipment Design; D006310:Hearing Aids; D006801:Humans; D008768:Methylmethacrylates; D006113:United Kingdom
D008768:Methylmethacrylates