Adaptive filter for correcting the transfer characteristic of electroacoustic transducer
US5694476A · kind A · utility
Inventor
Key dates
| Filing date | Sep 15, 1994 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Sep 15, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/08
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An arrangement is provided for converting an electric signal into an acoustic or a mechanic signal comprising a transducer (11), a linear or nonlinear filter (1) with controllable parameters, a sensor (12), a controller (24), a reference filter (20) and a summer (17). The filter (1) is connected to the electric input of the transducer and is adaptively adjusted to compensate for the linear and/or nonlinear distortions of the transducer and to realize a desired overall transfer characteristic. The filter has for every controllable filter parameter an additional output (7) supplying a gradient signal to the controller and a control input (10). The summer (17) provides an error signal derived from the sensor output and reference filter output. The controller contains a circuit (53) for filtering the gradient signal and/or a circuit (25) for filtering the error signal, a multiplier (51) and an integrator (57) for producing a control signal to update every filter parameter. This arrangement omits off-line pre-training and adapts on-line for changing transducer characteristics caused by temperature, ageing and so on.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.