Quality of text-to-speech feature

Hi all,

I want to know how much better is text-to-speech feature in voiceXML asterisk as compared to other voiceXML products in market like Plum Voice Portals(providing IVR services). It’s been said that asterisk provides better quality of text-to-speech feature. I want to know how it is better whether it supports more audio extensions like (.wav) or it povides more benefits in text-to-speech. What are those points that makes better quality of text-to-speech feature in Asterisk.

I searched for better quality of text-to-speech in Asterisk, but it’s not specifically provided how it’s better.

Please help, i need to answer it.
I’m stuck.

Waiting for response.

Thanking you.