What does the "Echo" button do?

[coolsoundman]

I notice that on the tracks in sonar, there is an echo button. I move my mouse over and it says that its an input echo. Can someone tell me what this button does and how is it used? Or is it mainly for using midi?

[mixsit]

A live input to that track will be sent back out for monitoring -plus your latency delay.
Wayne

[dachay2tnr]

It allows you to hear any FX you have enabled in Sonar in realtime, as you are recording. So if you have reverb setup on the track, you can hear your voice with the reverb applied while recording.

The downside, as mixsit noted, is that it will be delayed by the amount of your latency. If the latency is too great (generally more than 5 ms) it will actually be heard as an echo, and can be quite distracting.