Here is a stupid little tool I just hacked together in a (/very) few minutes starting from
Krasas information:
http://helicoid.de/scumm/speech.zip
It just dumps the sample name and the spoken line in English to the standard output and expects the speech.info in the same folder. So just do something like "speech.exe > speech.txt" or so.
I bet with some minor modifications you can just create a file suitable for the ScummSpeaks tool.