Frequency-domain delayless active sound quality control algorithm

Recent advances on active noise control: open issues and innovative applications

“…The use of an active noise equalizer (ANE) [160] or active sound profiling [161], which changes the amplitude of noise components with predetermined values, is a useful and important extension of ANC. The narrowband ANE [162][163][164][165][166] can be implemented to individually control each harmonic of a periodic noise, and further extends to become a broadband ANE [167,168] using a shaping filter to shape the desired broadband noise spectrum. Wang and Gan [96,99] investigate the sensitivity of the ANE under an imperfect secondary-path estimation.…”

Enhanced filtered-x least mean M-estimate algorithm for active impulsive noise control

“…It has been known that the computational cost of FxLMS Adaptive Controller Impact noise algorithm is mainly determined by the orders of the controller and finite impulse response (FIR) filter for the secondary path model. Assuming the order of adaptive controller is N and the filter order for secondary path is M. In the FxLMS algorithm, the total computations required in each process are equal to 2(2N + M) [17]. As compared with the FxLMS algorithm, the MFxLMM algorithm requires additional median computations in the variance estimation process.…”

Steady state behavior of normalized frequency domain adaptive filter in noncausal circumstances

“…Equation (8) can be regarded as an averaged periodogram for the estimation of the power spectrum [13]. The factor α determines the averaging degree, and the spectrum becomes smoother with its decrease.…”

“…Usually the NFLMS algorithm benefits from faster convergence speed for reference signal with large eigenvalue disparity of the autocorrelation matrix, which makes it very attractive in many application scenarios, one of which is the active noise control system [6][7][8][9][10]. However, it has been noted that the NFLMS cannot converge to the optimal Wiener filter [2,3], especially when the reference signal lags behind the expectation signal [4], a typical phenomenon happened in noncausal circumstances.…”