Car noise, Youtube links

Hi, unfortunately, the car noise, which had been discussed earlier, occurred for the 4th time yesterday. So the loose, now removed wheel caps were not.It only appears sporadically. u. is not reproducible. I found the noise on Youtube, here the links http://www.youtube.com/watch?v=hlQwr2sGjFU http://www.youtube.com/watch?v=i9DMsqSk7aM At the beginning it sounds the same as on the first video. On the second the noise is shorter and quieter to hear (a dull hay). However, as the journey increases, it gets louder and louder and more can be heard a screeching, grinding noise. That’s not to be heard on the videos. The noise does not change when giving/braking. However, if the car is short, a traffic light without the engine is enough, then it is no longer available. Does someone have an idea based on the videos? Through the videos it would have to be possible to find the cause now. I would still be on the Radla. But in my workshop I was told that the noise would have to occur continuously, always, it would be the wheel bearings. So that was excluded from the beginning.Is this information really correct or can a defective wheel bearing report sporadically?Need urgent help, because I have concerns that I will break my Twingo, my workshop has no plan so far. LG Dawson