"Dropouts" are very brief breaks in the sound. There are dropouts especially on magnetic tape. Many dropouts are so tiny, that very often the listener doesn't pay any attention to them. However, a little bit longer dropouts sound like a "nudge" or a cut in the music. Dropouts are caused by wrinkled tape, a stretch at the tape edge, or because the tape is not running smoothly. The tape moves away from the playback head for a very short instant, which causes a break in the sound. High frequencies are typically attenuated first.

The following example is an excerpt from J.S. Bach's Air. It's performed by Heimo Haitto and Cyril Szalkiewicz. The recording was made into a Compact Cassette in a rehearsal session. The example is published by kind permission from Tuomas Haitto.

There are three dropouts in the audio

The audio after the editing

The longest gap in this example is 14 milliseconds "long".

It is usually pays back to fix the dropouts, even those not apparent to the ear. The result sounds usually much cleaner.

A Gap in the audio

Sometimes there is a total gap in the audio. There is no sound at all, there is just a silent section in the middle of the sound.

This clip had a gap of a third of a second. The high frequencies are lost for almost half a second.

The original clip is on the left and the edited version on the right. Please click on the pictures to listen to the clips.

Click the picture to play

Click the picture to play

The problem with a long break in the audio is, that there isn't enough material before or after the gap to use interpolation to fill the break, as can be done with short dropouts. Long gaps need more editing, and time. Some people call this kind of audio repairing "magic", but in fact handicraft skills and patiency are much more useful.

The excerpt is from Beethoven's Sonata 2, A Major. The performers are Heimo Haitto and Kauko Kuosma. Thanks to Tuomas Haitto for the permission to use the recording.