Both my daughters loved this thing! There's a switch on it so that you can have it do the alphabet, regular drum sounds, play music, or counting.
They have a newer model out now that I haven't tried, and there's a Spanish version of this drum as well.
As far as age range goes, I'd say that children from 6 months to around 4 years would have fun with this, all day in some cases. That said, even my six year old loves it, for the drum sounds alone!
As the child beats on the drum with their little hands, there's a red digital read out on the top of the drum, that will display the letter or number they are on. For the drum sounds, it just kind of glows, without a definable symbol there.
We bought this a few years back, when it was quite popular, and so some of my friends who had children also purchased one. If noise is a major irritant for you, this might pose a problem, since the kids will likely be banging on this all day. For me, it was enough to know that they were occupied, having fun, and learning all at the same time!