DC offset is a nasty little component of many digital audio signals that, while often inaudible, can add to the noise floor of your project. At worst, DC offset can result in an audible “click” on the beginning or end of an audio clip that has been edited. You can see DC offset by zooming in on a view of a waveform. If the clip’s zero-crossing line – the place where the waveform crosses from positive to negative voltage or vice versa – is actually not at zero, but higher or lower, you’ve got DC offset. If you hear clicks or experience low-level distortion you can check for DC offset by recording a few seconds of silence. If the resulting waveform appears above or below the zero line, there’s probably DC offset.
The “Remove DC Offset ” function- and Logic Pro, Digital Performer, Sound Forge, and most other digital audio applications include this – is an easy way to eliminate the DC component from audio signals.