[Freeswitch-users] Using 16 KHz sounds

Hello, I use Cepstral in my mod_managed FS application. I mainly use Session.Speak and PlayAndGetDigits in my code to play WAV / audio text. When I started using FS and got a stable program running, I used Cepstral Allison 8 KHz voice. But frequently I get choppy type of sound. Earlier it was acceptable but now some callers seem to have difficulty understanding the call audio. Would it help if I get 16 KHz sounds / Cepstral license? What are changes I would need to make? Thank you for any help. Malay Thakershi