Recent advances in hearing aid selection and adjustment.

Recent research has shown that speech is most intelligible for hearing-impaired individuals when it is amplified to a comfortable level in specific frequency regions between 250 and 6,000 Hz, and is limited below the discomfort level. If commercial hearing aids and earmold coupling are adjusted appropriately, they will provide amplified sound within these parameters for most hearing-impaired individuals. A clinical procedure is described 1) to preselect an aid and earmold with the approximate electroacoustic characteristics that are needed, 2) to determine the gain actually provided by this hearing aid/earmold combination, and 3) to adjust the hearing aid and/or earmold if the gain and maximum output do not meet the prescribed criteria, or if the wearer finds the sound quality unacceptable.