Distortion product emissions are objectively measurable in the ear canal

Evidence

Based on purely objective methods and apparatus, distortion product emissions can be measured in the closed outer ear canal by a sensitive microphone. A linear set up and a very low noise floor are necessary to produce relevant data. The method of cancellation can also be used by adding a tone of the corresponding frequency adjusted in level and phase, so that the objectively measured difference tone which appears is compensated to indetectable low values. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 330

Categorization

• DEFINE: Distinguishes objective emission measurement from perceptual hearing cancellation — the two complementary methods.