A modified polymer foam earplug for the hearing aid evaluation

Functional gain was compared with 12 subjects using three earmold conditions: an E-A-R polymer foam earplug modified for use with a hearing aid, a personal custom earmold, and a best-fit receiver-type stock earmold. Functional gain was equivalent between the modified E-A-R earplug and the custom earmold conditions. The stock earmold condition resulted in a significant shunting of low-frequency amplification. The gain control of the personal hearing aids could be adjusted to the user comfort level gain setting without resulting in acoustic feedback in only the modified E-A-R earplug and custom earmold conditions. These findings are discussed relative to the hearing aid evaluation.