Bone anchored hearing aid with adjustable resonance damping
The invention relates to a bone anchored hearing aid with a sound processor which generates a vibration signal and serves the signal at a vibrator for transmission of the vibration signal into the skull bone of a wearer and where a resonance damping system is provided in the hearing aid and comprising an electronic notch filter having a notch filter center frequency F1, wherein the notch filter frequency F1 is below a resonance frequency F sim of the hearing aid as measured in a standard skull simulator.
1. A bone anchored hearing aid, comprising:
a processor that performs signal processing, the processor configured to generate an output signal and to provide the output signal to a vibrator for transmitting a vibration signal into a skull bone of a wearer of the bone anchored hearing aid,
the processor including
a resonance damping system including a programmable electronic notch filter having a notch filter center frequency F1,
a resonance frequency determination unit configured to determine a resonance frequency (F real ) of the vibrator when the vibrator is mounted on the skull bone of the wearer, and
an adjusting unit configured to adjust the center frequency F1 of the programmable electronic notch filter based on the determined resonance frequency (F real ), wherein
the processor is configured to determine the resonance frequency (F real ) and to adjust the center frequency F1 of the programmable electronic notch filter each time the bone anchored hearing aid is powered on.
2. Bone anchored hearing aid as claimed in claim 1 , wherein
the notch filter center frequency F1 is 30 Hz to 80 Hz below a resonance frequency F sim of the hearing aid as measured in a skull simulator.
3. Bone anchored hearing aid as claimed in claim 1 , wherein
the processor includes a meter configured to measure current consumption at various vibration frequencies when the hearing aid is anchored to the skull bone of the wearer.
4. Bone anchored hearing aid as claimed in claim 3 , wherein
the processor includes a tone generator configured to perform a tone sweep in order to determine the resonance frequency F real of the hearing aid when anchored to the skull bone of the wearer, and
the processor is further configured to store in a memory unit M of the signal processing device the resonance frequency F real when the resonance frequency F real is determined.
5. Bone anchored hearing aid as claimed in claim 4 , wherein
the processor is further configured to adjust the center frequency F1 of the notch filter according to the stored resonance frequency F real in the memory unit M.
6. The bone anchored hearing aid as claimed in claim 1 , wherein
the notch filter center frequency F1 is below a resonance frequency F sim of the hearing aid as measured in a skull simulator.