Seaman - English Voice recogntion?

So the most odd title from Dreamcast game catalogue was ported to PS2... "japan only" .
http://www.gamefaqs.com/ps2/533273-seaman/data
I knew of the sequel ages ago, but just noticed about the original re-release about a couple of weeks ago.
After looking at PS2 audio files, surprise! they're same format than DC (AFX stored in AFS container) all in japanese, as expected. I wondered if the voice recognition system was japan-only (most likely) or japan-english mix (presumably, because japanese gamers use to understand english and this feature may have be included for a western release which never happened). In that case, I can play it without know japanese or maybe we could simply swap files and go .
I crossed my fingers for the game being able to play without the usb headset but nope (I'll buy a cheap one if there's no remedy)
There's very few info about this port, but found this interesting posts (users PSOGuy25 & FranckKnight posts):
http://www.gamefaqs.com/boards/942422-dragon-quest-iv-chapters-of-the-chosen/42619928?page=2
To summarize, FranckKnight replies: "In the case of Seaman, I can't say I have all of the technicaly data to even TRY something like that, but I'm thinking that the main problem would be the voice recognition. Unless the game uses English recognition, the entire voice system would need to be pulled out and replaced by one that would recognize English."
Any charitative soul with the hardware and will to check this? Do the PS2 Seaman recognizes english voice?
If it doesn't (and you're hex-code skilled), any trace of a hidden english system like Dragon Quest IV (FranckKnight dixit).
Thank you for your time and patience!