What is part of DURCH tests?

DURCH tests are part of the German certification process for hearing aids. They don't refer to a single test, but rather a series of tests assessing different aspects of hearing aid performance. Specifically, the tests are part of a larger framework focusing on the objective measurement of hearing aid characteristics. This contrasts with subjective tests that rely on user feedback.

Key aspects measured in DURCH tests include:

* Linearity: How accurately the hearing aid amplifies sounds across different frequencies. Deviations from linearity indicate distortion.

* Frequency response: The amplification provided by the hearing aid at different frequencies. This helps assess the overall sound quality and the effectiveness of frequency shaping.

* Total harmonic distortion (THD): The amount of distortion introduced by the hearing aid. Higher THD indicates poorer sound quality.

* Output sound pressure level (OSPL): The maximum sound pressure level the hearing aid can produce. This is important for understanding the hearing aid's power and its ability to amplify faint sounds.

* Equivalent input noise level (EIN): The level of background noise produced by the hearing aid itself. Lower EIN is better.

In short, DURCH tests are a battery of objective measurements designed to verify the technical performance specifications of hearing aids sold in Germany. They ensure that the hearing aids meet specific quality standards.