Hearing aid benefit related to the POGO amplification formula, evaluated from insertion gain measurements of two BTE hearing aids.

The purpose of the study was to perform clinical tests with two BTE-hearing aids (BTE-HAs) having different frequency characteristics--and to correlate the results of the clinical tests to self-assessed use and benefit. The material comprised 16 subjects (SS) (median age: 74.5 years, range: 70-83 years) with moderate, sensorineural hearing losses. Patient selection criteria were specified according to the requirements for amplification at 4 kHz. All SS were fitted with two different types of BTE-HAs which were compared by the SS in a 3-months field study. The effect of the HAs was subjectively evaluated by a questionnaire and objectively by determination of the discrimination score in background noise (DN measurements). Furthermore, the need of amplification was checked by repeated insertion gain (IG) measurements. There was no significant difference in final HA choice. The DN measurements and IG measurements (both measured at most comfortable listening level (MCL] were significantly better with one of the HAs. The conclusion is that a correlation exists between optimal discrimination score in background noise and amplification at 2 and 4 kHz. The objective findings, however, were not reflected in any of the subjective parameters.