How can I disable the audible MWI on Polycom phones?

Question

By default, when a Polycom VoIP phone has a voicemail message waiting, it both lights the MWI light, and plays a sound every several minutes. I've never met a more self-important feature in a phone, ever.

How can I make that sound go away, forever?

Answer 1

Add this to the XML config you pass to the phone. (I've only tested this with firmware 3.1 and higher.)

<MESSAGE_WAITING 
    se.pat.misc.messageWaiting.inst.1.type="silence" se.pat.misc.messageWaiting.inst.1.value="0" 
    se.pat.misc.messageWaiting.inst.2.type="silence" se.pat.misc.messageWaiting.inst.2.value="0"
    se.pat.misc.messageWaiting.inst.3.type="silence" se.pat.misc.messageWaiting.inst.3.value="0"
    se.pat.misc.messageWaiting.inst.4.type="silence" se.pat.misc.messageWaiting.inst.4.value="0"
/>

The sound you hear is actually a four-note tune. You have to turn all four notes to silence to completely disable audible MWI.

Answer 2

You can change it for all your phones by making the change in your sip.cfg file. I have a sip_318.cfg and a sip_326.cfg - one for my ip601's and one for my ip430's. If you make his changes, you can disable the sounds. I found the noise to be annoying, too, so I added Jeremy's edits too.