You must start responding to the caller quicker and start talking faster... Next! No seriously, are there any other symptoms like crackling. Is the speaker phone on/off (try and see if activating/deactivating improves things). Has this issue just started recently or long time. Are you using a 3rd part dialer.
It's been like this for the best part of a month. I did have BT Smart Talk installed and only noticed it happening after that, so I removed it. No crackling. Will also try the speaker on/off during a call.
I appreciate the following might be a pain but, if you have recently upgraded to Jb, try connecting pc utility and run a repair. else try a force shutdown (power button and volume.+ till you here sound). Finally, a factory reset (back up apps if important to you). This is generic fixing but if smart talk has left a ghost it may clear it out.
