Nuance mobile sdk: "There appears to be a lot of background noise"

After starting the listener a couple of times I only get "There appears to be a lot of background no开发者_开发技巧ise" errors, in a totally quiet environment that is.

It turned out that the listening method was called twice and the demo code didn't handle this nicely. it worked after adding this to the official code:

if (transactionState == TS_RECORDING) { return; }