ACDB AudProc vol returns = -19

Question

I work in an Android application that performs audio streaming using the opentok library. After 15/20 minutes, the sound stops working, without failures, there are no exceptions, only this error is in the logs.

ACDB AudProc vol returns = -19

Nexus 5 android kitkat

Has anyone seen this before and can offer a workaround? Many thanks

UPDATE: It seems that the problem only occurs with the audio / video stream. With the audio stream / only I get this error, but the sound continues to work.

I have no idea what the cause of the problem is and what the error means.