Like noises in a swound!
The usual meaning of this archaic middle english word is “to swoon”. Curious usage, he is perhaps using it in in its “ecstatic” sense. To swooon in ecstasy. And one makes noises, generally, while in ecstasy. For those who find this reading a bit fetched, they are encouraged to examine the soliloquey of Orsino in The Twelfth Night that begins “If music be the food of love, play on,” and the interesting usage of the word that appears therein. It is not terribly difficult to think that Coleridge picked the word up while reading Shakespeare (as the word was already well out of use by his time).
To help improve the meaning of these lyrics, visit "Rime Of The Ancient Mariner" by Samuel Taylor Coleridge and leave a comment on the lyrics box