My voice breaks up (but perfect signal and incoming sound, and fine while roaming)
 

A strange problem has just developed with my Sprint Diamond. My voice breaks up badly for parties on the other end, even using a headset. However, I can hear them perfectly. I recorded my voice with the "notes" software, played it back, and it sounded perfectly fine.

I did a hard reset yet the problem persists. What could be going on?

Wirelessly posted (HTC Diamond: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11) Sprint MP6950SP)

First, I would go from the Start Menu to Settings and click on the System tab. Then scroll down to the UpdatePRL Icon and click on it to make sure you have the latest update.
That may help.
If you have recorded your voice with the internal microphone in the phone and your voice sounds normal then I doubt you have a hardware problem with your device.
You said you used a headset and that may be causing problems because noise cancelling may kick in to try to reduce background noise which could cause your voice to sound choppy. If you are calling people that are also using mobile phones then the problem may be on their end. If they are on another network like AT&T or T-Mobile that may be causing problems because of the conversion from cdma to gsm.
Call someone that has the same carrier as you and see if you have the same issue.

Re: My voice breaks up (but perfect signal and incoming sound)
 

my voice transmits fine when i'm roaming (when that triangle icon appears at the top) but not when using the network selection method listed as "standard." should i try "automatic-a" or "automatic-b"?

horndoctor: I just now updated to PRL 60662 and i'm having the same problem. this occurs when sending myself a voicemail, and when talking to someone on AT&T. the noise cancellation feature doesn't seem to change anything.

Re: My voice breaks up (but perfect signal and incoming sound, and fine while roaming
 

Try turning the volume down. I had some problems similar to this, but it was because the earpiece was getting picked up by the phone.

Although, it doesn't sound like that's the case here, it's easily worth a shot.

Re: My voice breaks up (but perfect signal and incoming sound, and fine while roaming
 

basilray: i have the volume on the lowest setting (although it does still seem a little loud when using the headset, but that shouldn't be picked up by the mic)

Wirelessly posted (HTC Diamond: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11) Sprint MP6950SP)

Honestly, it doesn't sound like there is a problem with your phone but rather a network to network problem. I've personally heard of this happening a lot with AT&T. I bet if you call and talk to someone with another Sprint phone or even Verizon you won't have this issue.