And if OpenEarsLogging is turned on, it is then followed by
Error -66681: Unable to start the Audio Queue.

This error appears when I make the first method call out from within the pocketsphinxDidReceiveHypothesis method.

For example, I create a simple method, dummy(), which gets called from within pocketsphinxDidReceiveHypothesis. The error appears when this method is called:
– (void) pocketsphinxDidReceiveHypothesis:(NSString *)hypothesis recognitionScore:(NSString *)recognitionScore utteranceID:(NSString *)utteranceID {
[self dummy]; /// DEBUG
…..
…..

And from that point on, no fliteController output occurs and no more speech recognition occurs.
My code has previously worked fine, so It seems to be something I have changed, but I have been unable to track down what it is. Any suggestions?

@interface Speech : NSObject

This is because it plays some pre-recorded sound clips as well as fliteController output, and I want to know when the clips are started and finished so i can turn off speech recognition during those sounds.
If I remove the ‘AVAudioPlayerDelegate’, I seem to be able run consistently without the error occurring.

Is it valid to have the class as a delegate of both? Could there be some conflict that is causing this error and lock-up?

Do you want to show me some logs featuring OpenEarsLogging and verbosePocketSphinx for the timeframe in which this is occurring? Maybe there are some hints.

Something to just double-check is that a lot of AVAudioPlayer sample code contains unneeded calls to AVAudioSession and a lot of developers who asked me about similar issues found calls to the audio session in their code that were responsible. It might be worth a quick project-wide search for “audiosession” without case matching to make sure that some audio session overrides didn’t sneak in there.

A search for AudioSession revealed the two methods: audioSessionInterruptionDidBegin and audioSessionInterruptionDidEnd, but commenting them out didn’t fix the problem. Here is the output:

2012-10-14 15:36:19.525 RR[66801:c07] VC Pocketsphinx calibration is complete.
2012-10-14 15:36:19.526 RR[66801:c07] Speech: Pocketsphinx calibration is complete.
2012-10-14 15:36:28.107 RR[66801:1f07] Speech detected…
2012-10-14 15:36:29.864 RR[66801:1f07] Processing speech, please wait…
2012-10-14 15:36:29.869 RR[66801:1f07] Pocketsphinx heard “START” with a score of (-1557) and an utterance ID of 000000000.
2012-10-14 15:36:29.870 RR[66801:c07] The received hypothesis is START with a score of -1557 and an ID of 000000000

— here i make a call to my dummy() function – (void) dummy { NSLog(@”dummy”);} —

2012-10-14 15:36:40.707 RR[66801:1f07] aq@0x9671000: ConvertInput using invalid anchor time
Error -66681: Unable to start the Audio Queue.
2012-10-14 15:36:40.708 RR[66801:1f07] Listening.
2012-10-14 15:36:40.708 RR[66801:c07] dummy

2012-10-14 16:15:29.380 RR[68064:c07] Flite sending interrupt speech request.

before returning to the main loop.

And to complicate it a bit more, i have now removed the inheritance from AVAudioPlayerDelegate, which fixed the problem yesterday, but now i am still getting the error – so it may not have been the cause.

Not debating that it is helping the issue you are seeing, just that it is probably ultimately due to something else. I haven’t seen the full logs and I imagine there are nuances to the code that can’t be put across via small snippets but it would be great if you could email me a stripped-down test case. Looking at this report of the same issue, it really looks like the audio session category is being overridden somewhere:

http://stackoverflow.com/questions/5215919/convertinput-using-invalid-anchor-time-error-received-when-recording-on-device