Adaptive filtering algorithm training signals incorporate
adaptation-enhancing signals having properties, such as spectral
whiteness and rapidly decaying auto-correlation between samples, which
allow the adaptive filtering algorithms to converge more quickly as
compared to conventional algorithms. Exemplary adaptation-enhancing
signals are incorporated such that the training signals are not
perceptibly altered as compared to conventional training signals. For
example, in a hands-free telephony application, an adaptation-enhancing
signal according to the invention is dynamically tailored so that it is
masked by a loudspeaker signal (the conventional training signal) and is
thus inaudible to hands-free telephone users.