What does the crowd say? Watermelon, cantaloupe, watermelon, cantaloupe...?

Or is it walla walla walla?

I saw a movie once, probably twenty years ago, in which one character is a Hollywood old-timer who's known in the biz as the World's Greatest Extra. Another character says, awestruck, "He invented the 'Courtroom Walla'!" It's explained that in courtroom dramas, when the verdict is announced, everyone in the courtroom softly says, "walla walla walla," creating a nice, low-level hum of excitement without anything really discernible in it.

Or are they just saying murmur....



Is the word "murmur" onomonopia? OED says:

Etymology: Partly < Middle French, French murmure indistinct expression of feeling by a number of people (c1170 in Old French), subdued expression of discontent (c1200), muted noise (c1230), sound of a light breeze (1555), respiratory murmur (1819 in passage translated in quot. 1821 at sense 5) < murmurer murmur v.; and partly < its ultimate etymon classical Latin murmur a low, continuous sound, a subdued or indistinct utterance, such an utterance indicative of anger or resentment, a reduplicated imitative formation....

The answer seems to be partly.