Hi Samlkh, kindly try using the Audio Diagnostic Tool and see if that fixes the problem.
You may refer to this article for complete instructions on how to use the tool:
http://support.brillkids.com/entries/20433747-how-to-use-the-audio-diagnostic-toolIf you are still having sound playback problems after running the Audio Diagnostic Tool a few times, please write to us at support[at]brillkids[dot]com and attach a diagnostic report so we can troubleshoot further:
http://support.brillkids.com/entries/20438423-how-to-create-a-diagnostic-report-for-your-brillkids-learning-systemI hope this helps!