Abstract: In embodiments of this invention howling sounds are removed without disturbing speech and music. Microphone signals are converted to the frequency domain where howling frequencies are detected and estimated using howling to noise ratios. A notch filter adaptively designed for the howling frequency is applied to remove the howling.

Abstract: In embodiments of this invention howling sounds are removed without disturbing speech and music. Microphone signals are converted to the frequency domain where howling frequencies are detected and estimated using howling to noise ratios. A notch filter adaptively designed for the howling frequency is applied to remove the howling.

Abstract: According to an embodiment of the present invention, a method for interfacing of application programs with operating system device drivers is provided. The method includes a variety of steps such as assigning an arbitrary message number to each of a plurality of functions from a device driver. Wrapper programs for the application and the device driver are provided. The method then includes a step of providing a ‘surrogate’ function for the application to call. Parameters passed into the function are extracted by the wrapper program for the application. The parameters are next stored into a data packet along with a corresponding message number. Next, the data packet is sent to the wrapper program for the device driver. In a subsequent step, the device driver wrapper program determines which function the application is invoking by the message, unpacks the parameters from the data packet and calls the corresponding function in the device driver.