Interesting! I'm inclined to think it was due to a particularly under-powered device (e.g., Kindle Fire devices, the kids version especially), since the recording and the audio stimulus go on at the same time? On some lower-end devices, sound duplex processing (outputting sounds and recording at the same time) can be a taxing task. You mentioned that you heard the audio stimulus in the recording, which points to this hypothesis as well - the tablet CPU was so busy that it couldn't keep up with echo cancellation!
Is it necessary to start recording as soon as the audio stimulus starts playing? If not, that might be the first point to optimize. For example, use the audio stimulus' "barrier" property and delay the recording till after the audio stimulus finishes playing.
We'll look into if there are more efficiency ways to play an audio file too, but I don't think there's too much free performance to be squeezed out of there, unfortunately.
BTW - thanks for the super detailed illustration!
Is it necessary to start recording as soon as the audio stimulus starts playing? If not, that might be the first point to optimize. For example, use the audio stimulus' "barrier" property and delay the recording till after the audio stimulus finishes playing.
We'll look into if there are more efficiency ways to play an audio file too, but I don't think there's too much free performance to be squeezed out of there, unfortunately.
BTW - thanks for the super detailed illustration!