Hearing aid with feedback compensation
First Claim
1. A hearing aid of the type havinga1) a primary microphone for receiving ambient sound and for producing electrical signals corresponding thereto on a primary signal path,a2) an amplifier for amplifying the electrical signals on said primary signal path to produce amplified signals,a3) an electro-acoustic transducer for converting said amplified signals into acoustical signals and for directing the acoustic signals toward the user'"'"'s eardrum or other sound-sensitive organ, andb) at least two secondary signal paths each leading from a location in a predominant sound-transmission path between said transducer and said amplifier, the transmission times (Δ
- t) along each of said secondary signal paths being substantially equal to the transmission time along said predominant sound-transmission path from each said location to said primary microphone, the output signals from each of said secondary signal paths being delivered to the input of said amplifier substantially in opposite phase and equal amplitude to the signals received by said amplifier from said primary microphone and caused by sound to be propagated along said predominant path.
1 Assignment
0 Petitions
Accused Products
Abstract
In a hearing aid with feedback compensation by virtue of at least one secondary microphone feeding into a delay unit and an attenuator feeding into one input of a difference amplifier, the other input with opposite polarity of which is connected to the output of the primary microphone receiving the ambient sound to be amplified and fed into the hearing-aid receiver and output duct, at least two secondary signal paths are provided. Each path comprises a secondary microphone with its associated delay unit and attenuator. An operational control unit may select the strongest signal to be used for feedback compensation. This makes it possible to achieve feedback compensation in various situations, such as may arise e.g. with an "in-the-ear" hearing aid when the user is chewing or yawning, creating various possible paths from the output duct past the housing of hearing aid to the primary microphone.
116 Citations
13 Claims
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1. A hearing aid of the type having
a1) a primary microphone for receiving ambient sound and for producing electrical signals corresponding thereto on a primary signal path, a2) an amplifier for amplifying the electrical signals on said primary signal path to produce amplified signals, a3) an electro-acoustic transducer for converting said amplified signals into acoustical signals and for directing the acoustic signals toward the user'"'"'s eardrum or other sound-sensitive organ, and b) at least two secondary signal paths each leading from a location in a predominant sound-transmission path between said transducer and said amplifier, the transmission times (Δ - t) along each of said secondary signal paths being substantially equal to the transmission time along said predominant sound-transmission path from each said location to said primary microphone, the output signals from each of said secondary signal paths being delivered to the input of said amplifier substantially in opposite phase and equal amplitude to the signals received by said amplifier from said primary microphone and caused by sound to be propagated along said predominant path.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
Specification