Bone conduction hearing aid system

A bone conduction hearing aid system, comprising:

• a right ear microphone arrangement adapted to be located at or close to a user's right ear, and a left ear microphone arrangement adapted to be located at or close to a user's left ear;
• a right ear signal processing unit for processing audio signals captured by the right ear microphone arrangement from ambient sound, and a left ear signal processing unit for processing audio signals captured by the left ear microphone arrangement from ambient sound;
• a right ear bone conduction output transducer adapted to be located at or close to the user's right ear for stimulating a user's right ear cochlea according to right ear output audio signals, and a left ear bone conduction output transducer adapted to be located at or close to the user's left ear for stimulating a user's left ear cochlea according to left ear output audio signals;
• a right ear cross-talk compensation filter unit for generating a right ear cross-talk compensation signal from processed audio signals of the right ear signal processing unit according to an estimated transcranial transfer function from the right ear bone conduction output transducer to the left ear cochlea, and a left ear cross-talk compensation filter unit for generating a left ear cross-talk compensation signal from processed audio signals of the left ear signal processing unit according to an estimated transcranial transfer function from the left ear bone conduction output transducer to the right ear cochlea;
• and
• means for subtracting the left ear cross-talk compensation signal from the processed audio signals of the right ear signal processing unit in order to generate the right ear output audio signals, and means for subtracting the right ear cross-talk compensation signal from the processed audio signals of the left ear signal processing unit in order to generate the left ear output audio signals.

A hearing aid system, comprising:

• a first ear microphone arrangement adapted to be located at or close to a user's first ear, and a second ear microphone arrangement adapted to be located at or close to a user's second ear;
• a first ear signal processing unit for processing audio signals captured by the first ear microphone arrangement from ambient sound, and a second ear signal processing unit for processing audio signals captured by the second ear microphone arrangement from ambient sound;
• a first ear bone conduction output transducer adapted to be located at or close to the user's first ear for stimulating a user's first ear cochlea according to first ear output audio signals, and a second ear output transducer adapted to be located at the user's second ear for stimulating a user's second ear cochlea according to second ear output audio signals, wherein the second output transducer is a loudspeaker for emitting sound into an ear canal or an electro-mechanical transducer to be directly coupled to an eardrum, an ossicular chain or the cochlea;
• a first ear cross-talk compensation filter unit for generating a first ear cross-talk compensation signal from processed audio signals of the first ear signal processing unit according to an estimated transcranial transfer function from the first ear bone conduction output transducer to the second ear cochlea;
• and
• means for subtracting the first ear cross-talk compensation signal from processed audio signals of the second ear signal processing unit in order to generate the second ear output audio signals.

A method of providing hearing assistance to a user, comprising:

• capturing right ear audio signals from ambient sound at a position at or close to a user's right ear, and capturing left ear audio signals from ambient sound at a position at or close to a user's left ear;
• processing the right ear audio signals, and processing the left ear audio signals;
• generating a right ear cross-talk compensation signal from the processed right ear audio signals according to an estimated transcranial transfer function from a right ear bone conduction output transducer located at or close to a user's right ear to a left ear cochlea, and generating a left ear cross-talk compensation signal from processed left ear audio signals according to an estimated transcranial transfer function from a left ear bone conduction output transducer located at or close to the user's left ear to a right ear cochlea;
• subtracting the left ear cross-talk compensation signal from the right ear processed audio signals in order to generate right ear output audio signals, and subtracting the right ear cross-talk compensation signal from the processed left ear audio signals in order to generate left ear output audio signals;
• and
• stimulating the user's right ear cochlea by the right ear bone conduction output transducer according to the right ear output audio signals, and stimulating the user's left ear cochlea by the left ear bone conduction output transducer according to the left ear output audio signals.

A method of providing hearing assistance to a user, comprising:

• capturing first ear audio signals from ambient sound at a position at or close to a user's first ear, and capturing second ear audio signals from ambient sound at a position at or close to a user's second ear;
• processing the first ear audio signals, and processing the second ear audio signals;
• generating a first ear cross-talk compensation signal from processed first ear audio signals according to an estimated transcranial transfer function from a first ear bone conduction output transducer located at or close to the user's first ear to a second ear cochlea;
• subtracting the first ear cross-talk compensation signal from processed second ear audio signals in order to generate second ear output audio signals;
• and
• stimulating a user's first ear cochlea by the first ear bone conduction output transducer according to the first ear output audio signals, and stimulating the user's second ear cochlea by a second ear output transducer located at the user's second ear according to the second ear output audio signals, wherein the second ear output transducer (116B) a loudspeaker which emits sound into an ear canal or an electro-mechanical transducer which is directly coupled to a eardrum, a ossicular chain or the cochlea of the user's second ear.