It looks like Google has been recording your voice searches (German). There have been rumors all along and it was assumed this was going on. They have the actual voice recordings and their transcripts and also generate a “finger print” of your voice to be able to verify it.
If you extrapolate from that they can by now
- transcribe speech almost instantaneously,
- have (over time) enough data to recognize your voice among others and
- are also able to speak in your voice stitching together chopped-up samples of your speech.