Googles ReCaptcha is a joke, they have to fix that.
As a site owner you can´t even turn the audio version off.
It works much too good.

I'm not an Robot!

Buster: Captcha Solver for Humans de Armin Sebastian

Firefox:1 von 100 funtioniert es. in chrome immer!

This works really well! Thanks!

Two stars for the two times it worked, then stopped ..

Super

funktioniert nicht ...also weg damit

It does not work.
You should let users to specify custom ASR service (URL and API key).