An acoustically sealed earmold and a receiver adapter insertable into the ear of an individual with impaired hearing and used in conjunction with an external receiver to evaluate hearing. A unique method of coupling the receiver adapter to the earmold is also disclosed. The adapter is inserted into the...http://www.google.es/patents/US4412096?utm_source=gb-gplus-sharePatente US4412096 - Combination earmold and receiver adapter
