With my several experience, I found that to transfer wav file to Definity, I have to use active speaker / mini amplifier to increase volume gain level, because PC audio output produce pre-amp output (I don't know how to say the correct word).
With interface of active speaker and oudio output came from active speker, I connect it to callmaster IV to upload the announcement, the sound quality is good!
I have electronic circuit schema for interface recording and playback announcment, it cost only USD5. This circuit is to replace Callmaster IV (no nedd callmaster IV anymore). I have use this circuit to record and transfer back my announcement. Very cheap and useful, still need mini amplifier (or active speker with audio output plug) connect it to analog phone and transfer ann to PABX.
Also I using my own circuit for interface music on hold. only need 1 resistor 5 watt, and 4 of Capacitor non polarity. It work great for my Definity, and play 5 different music on hold to may call center without multi tenant on my system.
For voice editor, i am using sound forge 6.0. there are many setting for reduce noise or humm problem.