Some practical insights in multichannel active noise control equalization

In this paper, a novel adaptive algorithm for equalization of periodic signals using active control is developed. This algorithm actively cancels out a single frequency without changing the amplitude levels at close frequencies. The algorithm performance is compared with that of an adaptive equalizer previously reported (Kuo and Ji 1995 and Kuo and Morgan 1996). Both algorithms are used for a real multichannel system in order to equalize some given frequencies of a primary signal. The local active noise control system has been used to create an equalization zone. A two channel system is used and the total pressure is controlled at two microphones. A 4100 type Bruel manikin with two calibrated microphones at the ear canals has been used to obtain sound levels in a hypothetic listener´s ears. The equalization points are not only the error sensors positions but an area around them which is measured using the manikin