My client wants to listen in during the recording, is that possible?

Absolutely. Many programs designed for remote office meetings, such as Microsoft Teams and Google Meet, can be used perfectly to discuss the tone-of-voice, pronunciation, and intonation of a recording. If the sound quality needs to be higher, applications like Source-Connect and Session-Link can be helpful.

Can you also deliver files in µLaw or ogg-vorbis?Is Dutch the same as Deutsch? And Flemish? Danish?