Hi J,
Thank you for your response.
I confirmed the beep sound with your case. I attached it as below.
Please check it again.
(Please visit the site to view this file)
It seems that it did not improve the beep sound with your case.
Do you have any other ideas?
Best regards,
Kaka
http://e2e.ti.com/support/data_converters/audio_converters/f/64/t/183494.aspx