The Design And Implementation Of Acoustic Feedback Suppression Algorithm Based On SHARC DSP

In the amplification system, microphone capture voice signal then amplification processing, played back by the loudspeaker, the loudspeaker signal inevitably fed into the microphone. This closed loop is formed between speakers and microphone, it affects the performance of the system, decreases the quality of sound. Acoustic feedback refers to the acoustic coupling between the microphone an d loudspeaker, howling is the negative interaction between the speaker and microphone, it is the result of acoustic coupling.Acoustic feedback problems have been existed all the way in the sound reinforcement environment, there has been caused a large number of researchers proposed many solutions in the past few decades. The howling suppression method based on notch filter(NHS) is one of the most popular acoustic feedback control method. The howling suppression method based on notch filters includes two stages: the howling detection and notch fiter design.This paper bases on the project of digital audio processor, describes a available method of notch filter suppress howlings. The system is commonly used in the conference room, multimedia classroom, the venue and other universal occasions. This topic evaluate the characteristic of the feedback signal, select the optimal a method or a combination. By designing 8 IIR narrowband filters supress acoustic feedback, and by setting up a series of control parameters to reduce false detection probability.Subject shows the deisgn of ADSP21489 DSP software system, and the realization of the algorithm on the DSP, combined with the project requirements and done a lot of algorithms and system optimization. The algorithm achieved the rapid automatic suppress the feedback and the purpose of low quality damage, and can through the PC software to view real-time feedback frequency and the attenuation amplitude.