After some "research" we then bought this for our 8-year-old here. Although the spectacular low price (without batteries) corresponds to a non-straight Sennheiser compatible optics, and the volume control is not exactly on studio level. The sound quality does not fit into a high-end system, but you can distinguish men and women well. In addition, it may increase while singing directly, but also record the sung and then play. Here you can then even crossfade sounds and a Musikstückchen.
Our daughter was very happy, and so we were there then ... ;-)