Hi Jayta, if you haven't done so already, please run the audio diagnostic tool from your Little Reader's Support Tools window -- go to Support > Launch Little Reader Support Tools > Sound Problems then click on the "Start Wizard" button.
For detailed instructions, you may refer to this article:
http://support.brillkids.com/entries/20433747-How-to-use-the-Audio-Diagnostic-ToolIf you're still can't hear the sounds completely after the audio diagnostic tool has done all possible adjustments, do create a diagnostic report and send it to us at support[at]brillkids[dot]com:
http://support.brillkids.com/entries/20438423-how-to-create-a-diagnostic-report-for-your-brillkids-learning-system