Patent ID: 7477754
Filing Date: 2009-01-13
Classification: A61F,H04R

Abstract:
1. Method for counteracting the occlusion effect of an electronic device delivering an audio signal to an ear, wherein the electronic device comprises a transmission path with an external microphone or input line which receives a signal p ES from the environment, a signal processor and a receiver which receives a processed signal from the signal processor and delivers sound signals to the ear, whereby an ear piece is inserted into the ear canal and totally or partially blocks the canal whereby the sound conditions in a cavity between the ear piece and the tympanic membrane are directly or indirectly determined, and whenever conditions leading to occlusion problems are determined, transmission characteristic of the transmission path to the receiver counteracts the occlusion effect, monitoring the sound conditions in the cavity by an additional microphone which is acoustically coupled to the cavity, using the signal from the additional microphone in a feed back loop to the receiver in order to attenuate the low frequency part of the sound in the cavity, and forming the feed back loop to the receiver in the analogue domain.