It's so disappointing to read their response in this thread.

For real, beyond disappointing. In a way he is telling us nothing will be done to make custom voices work.

Well, even if they don't fix custom voices ever, I only hope they change default voices to something more suitable to the characters, most of the voices are kind of childlike, default valkyrie sounds like a 10 year old would, while the new face looks 20ish.

100% agree.  It has been this way since the beginning and they've given that answer before, but it's always been disappointing.

I can't imagine it'd be that hard to change.  It could be sent in literally 2 bytes of data since it only has 2 parameters: voice ID and pitch.

I wholeheartedly agree, this is something that should be a given. This is an option prevalent in almost every MMO I've ever played and with Black Desert striving to be so much higher quality, I'm pretty disappointed that this is the case.

Is there a reason behind it or was it just never implemented?

I've opened a suggestion thread for those that want to support this to be implemented.

It's probably not that simple, but I bet is not too much work either.