An Embedded-processor driven Test Bench for Acoustic Feedback Cancellation in real environments

In order to facilitate the communication among speakers, speech reinforcement systems equipped with microphones and loudspeakers are employed. Due to the acoustic couplings between them, the speech intelligibility may result ruined and, moreover, high channel gains could drive the system to instability. Acoustic Feedback Cancellation (AFC) methods need to be applied to keep the system stable. In this work, a new Test Bench for testing AFC algorithms in real environments is proposed. It is based on the TMS320C6748 processor, running the Suppressor-PEM algorithm, a recent technique based on the PEM-AFROW paradigm. The partitioned block frequency domain adaptive filter (PB-FDAF) paradigm has been adopted to keep the computational complexity low. A professional sound card and a PC, where an automatic gain controller has been implemented to prevent signal clipping, complete the framework. Several experimental tests confirmed the framework suitability to operate under diverse acoustic conditions.