Voice Shout through FreePBX?

I just got an installed FreePBX system dropped in my lap - no instructions or help - and no background in PBX (I’m a php/mySql developer). I’ve been tasked with interfacing (in PHP) to the system to send voice messages to clients. Won’t be using it for incoming, mailboxes or anything else - just plain old outgoing “voice shout” (at least that’s what the manager calls it). WE are using VoiceShot now (at a HUGE cost) which is why the PTB (Powers that be) are jumping to this.
Any help, answers, scripts, APIs - whatever?
Sure appreciate anything

Depends on your needs and skills nothing “built in” but easy to add

Ward has TeleYapper
http://bestof.nerdvittles.com/applications/

You also have GabCast which you can tie into the PBX system and do some really
KEWL stuff with and the cost is from FREE to CHEAP.
http://gabcast.com/