Listening system with an improved feedback cancellation system, a method and use

A listening device system, comprising:

• a first listening device, including
• a first housing,
• a first input transducer housed within the first housing for converting an input sound to an electrical input signal, the electrical input signal including a direct part and an acoustic feedback part,
• an output transducer for converting an electrical output signal to an output sound, a forward path being defined between the input transducer and the output transducer,
• a signal processing unit, and
• a feedback cancellation system for estimating acoustic feedback, the feedback cancellation system including
• an adaptive FBC filter arranged in parallel to the forward path, the adaptive FBC filter including
• a variable FBC filter part, and
• an FBC update algorithm part for updating the variable FBC filter part, the FBC update algorithm part receiving first and second FBC algorithm input signals influenced by the electrical input and the electrical output signals, respectively, through a first and a second FBC update algorithm input signal path, respectively, the first and second FBC update algorithm input signal paths including a first variable filter and a second variable filter, respectively;
• a second device, including
• a second housing spatially located relative to the first housing, and
• a second input transducer housed within the second housing, the second input transducer producing an electrical update signal essentially consisting of said direct part of said electrical input signal;
• and
• a wired or wireless connection conveying the electrical update signal from the second device to the first listening device, wherein
• said first and second variable filters are updated on the basis of said electrical update signal,
• the first and second variable filters comprise a common control part and separate identical first and second variable filter parts configured to perforin identical filtering functions, and
• the common control part provides update information to modify a filtering function of the first and second variable filter parts.

A method of improving feedback cancellation in a listening device system including a first listening device with a first housing and a physically separate second device with a second housing, the method comprising:

• converting an input sound to an electrical input signal by a first input transducer housed in the first housing, the electrical input signal including a direct part and an acoustic feedback part;
• converting an electrical output signal to an output sound by an output transducer;
• providing an electrical forward path between the input and output signals comprising a processing function to modify the electrical input signal;
• providing an adaptive feedback cancellation filtering function for estimating acoustic feedback from said output sound to said input sound, the adaptive feedback cancellation filtering function including
• a variable FBC filter part and an FBC update algorithm part for updating the variable FBC filter part, the FBC update algorithm part receiving first and second FBC algorithm inputs, the first and second FBC algorithm inputs being influenced by the electrical input and the electrical output signals, respectively, through a first and a second FBC update algorithm input paths, respectively;
• providing that the FBC update algorithm inputs each comprises a variable filter function;
• producing an electrical update signal essentially consisting of said direct part of said electrical input signal by a second input transducer housed within the second housing;
• transmitting filter coefficients based on the electrical update signal from the first listening device to the second device.

A computer readable tangible medium encoded with instructions, wherein the instructions, when executed on a processor of a listening device system including a first listening device with a first housing and a physically separate second device with a second housing, cause the listening device system to perform a method, the method comprising:

• converting an input sound to an electrical input signal by a first input transducer housed in the first housing, the electrical input signal including a direct part and an acoustic feedback part;
• converting an electrical output signal to an output sound by an output transducer;
• providing an electrical forward path between the input and output signals comprising a processing function to modify the electrical input signal;
• providing an adaptive feedback cancellation filtering function for estimating acoustic feedback from said output sound to said input sound, the adaptive feedback cancellation filtering function including
• a variable FBC filter part and an FBC update algorithm part for updating the variable FBC filter part, the FBC update algorithm part receiving first and second FBC algorithm inputs, the first and second FBC algorithm inputs being influenced by the electrical input and the electrical output signals, respectively, through a first and a second FBC update algorithm input paths, respectively;
• providing that the FBC update algorithm inputs each comprises a variable filter function;
• and
• producing an electrical update signal essentially consisting of said direct part of said electrical input signal by a second input transducer housed within the second housing;
• and
• transmitting filter coefficients based on the electrical update signal from the first listening device to the second device.