Or are you using a third party reverb plug-in or something...That is weird.
Right click the little speaker in the task bar...Make shure all settings are correct.....I only had this
happen to me once , but that's cuz i was playing around w/the record settings on Sound Forge.
It had something to do w/the input settings, and there was a lever that done a sm. mic boost but, in turn ....gave it a reverb affect or echo.