A novel decorrelation approach for multichannel system identification

A subband implementation of a multichannel and multiple position adaptive room response equalizer

“…Some experimental results are reported in this section to show the effectiveness of the proposed approach. The performance of the decorrelation algorithm has not been included for space limitations and also because its effectiveness was fully demonstrated in [25]. Also the effectiveness of the multi-point approach has been demonstrated in several papers of the same authors, e.g., [6,8,19].…”

“…The multichannel input signals decorrelation is obtained by the psychoacoustic criteria of the missing fundamental [24], as reported in [25]. This psychoacoustic phenomenon is associated with the human capability of perceiving the fundamental frequency although it is not actually present in the signal.…”

“…This psychoacoustic phenomenon is associated with the human capability of perceiving the fundamental frequency although it is not actually present in the signal. Moreover, second-order time-varying all-pass filters are included in this approach so as to expand the solution to the entire frequency spectrum [25]. The scheme of the algorithm is reported in Figure 2, in which each input channel y p (n) of the decorrelation block, being p = 1, • • • , L, is divided into two subbands [19].…”

“…provides disparity among channels even if the fundamental frequency is the same. In particular, a right circular shift of one sample s(•, 1) is applied to the vector α(n) every Q samples [25], as explained in the following equation:…”

“…This characterization of the all-pass filter allows us to maintain the spatial perception of the speech [27] because the restriction |k p (n)| < 1 guarantees stability and causality of the filter and ensures that the inter-aural time delay difference between the two ears is lower than the well-known "just 130 noticeable inter-aural delay" [30]. As described in [25], the alteration in sound direction is negligible as the maximum variation in the time of arrival is about 40 µs for all frequencies.…”