The juge d'instruction can force the BEA to do it.
Reading the report of the group of experts appointed by the juge d'instruction one is left with the distinct impression that those experts have had access to the full sound recording, not just the transcript.
Since both the DFDR and the CVR memory modules were put under judicial seal as soon as they arrived on deck of the salvage vessel, and contain important evidence in a criminal proceeding, I guess that the judge has full access to both sets of data.