Echo Return Loss (ERL)

ERL is a measure of signal loss that comes back as an echo. A higher ratio corresponds to a smaller amount of echo; the higher the ERL the better.

To obtain an estimate of convergence or the Echo Return Loss Enhancement (ERLE), one must first estimate the coupling factor or the Echo Return Loss (ERL) of the loudspeaker-microphone enclosure. An estimate of the ERL is required to determine how much attenuation can be attributed to the echo path and how much can be attributed to the echo canceller.