Created attachment 68397 [details]
No idea whether that what I currently hear is intended scrambling, but I am afraid nobody can understand that.
It is simple: One four.
Besides: pointless bug as you know that it is not in the hands of TDF how reCaptcha creates their distorted audio.
And it should also be obvious that the audio cannot be crystal clear speech, as otherwise it would be easy to automatically break by speech-recognition software.
Thus: closing notourbug.
Just FYI: the audio-challenge created one of the easiest points to attack the captcha:
That weakspot is solved, but that should illustrate why you cannot expect clear voice.