VLC, for years, has had a very crappy resampler for speed changes. It makes it very hard to speed up video because the speech quality is ruined. The resampler seems to be cutting off the attack of sounds and this makes it hard to determine the initial consonants. No other modern player seems to have this issue. I can watch videos on 2x in YT without experiencing this issue. I can use XMplayer and not experience this issue. Whatever code/library VLC uses to both alter the time and alter the pitch is crap. It not only effects speech but music. It makes the music unnatural. There are modern algorithms that are far far better than the ancient crap VLC keep using. I'm sure the developers do not see it as an issue but that is typical.
Sometimes I wonder why I still use VLC.... I guess I need to learn to break bad habits?