1. A method of detecting in-band signaling tones in a communication system, comprising: performing a first adaptation of an adaptive filter of an echo canceller in response to detection of a far-end harmonic signal, wherein the adaptive filter provides an echo estimation signal; subtracting the echo estimation signal from a near-end signal that includes one or more in-band signaling tones to provide an error signal; detecting, using a tone detector, the one or more in-band signaling tones in the error signal; and performing a second adaptation of the adaptive filter in response to detection of a far-end non-harmonic signal.