An individualised acoustically transparent earpiece for hearing devices.

OBJECTIVE: An important and often still unresolved problem of hearing devices such as assistive listening devices and hearing aids is limited user acceptance - a primary reason is poor conservation quality of the acoustic environment. Approaching a possible solution to this problem, an earpiece prototype is presented and evaluated. The prototype is individually and automatically calibrated in situ to provide acoustical transparency, i.e., achieving an audio perception alike to the open ear.

DESIGN: A comprehensive evaluation was performed, comprising technical measurements on an advanced dummy head and listening tests, in which listeners directly compared sound perception through the prototype and a simulated open ear canal reference.

STUDY SAMPLE: Ten normal hearing subjects, including five expert listeners, participated in the listening test.

RESULTS: The technical evaluation verified good achievement of acoustical transparency. The psychoacoustic results showed that a reliable distinction between the two conditions presented was not possible for relevant communication sounds.

CONCLUSION: The prototype can be described as an initial realisation of an acoustically transparent hearing system, i.e. a device that does not disturb the perception of external sounds. In further developments, the device can be considered as the basis for systems integrating high sound quality, hearing support and other desired modifications.