sound bite

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A short audio or video clip taken from a speech or press conference and broadcast especially during a news report.
• noun A short, catchy statement resembling those quoted or replayed by reporters.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun journalism, television An extract from a speech or interview used as edited into a news or other broadcast; an interview clip, especially seen as particularly expressive or pithy.
• noun often pejorative A one-liner deliberately produced for this purpose; a statement specifically intended to be punchy and memorable.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a very short speech; usually on radio or television