Audio Quality

I am using i6net openvxi plugin with asterisk 11.9. Occassionally, I get pops even though prompt recordings are free of pops. Is there something I could do in asterisk settings to possibly improve that? Is there a diagnostic tool/troubleshooting steps which would identify the audio quality issues.

Thanks in advance

My apologies. The crackle and pops were, in fact, on the recording prompts.