Strange noise in Seat Leon

I have a 2002 Seat Leon that I hope to acquire recently.
A few days ago I started listening to a strange noise still on the engine where the band is going, it is like a Sumbido I thought the band was loose but already check it and not.
Someone could help me with this problem.
thank you.

Huy friend is complicated the issue of noise because what you listen to as a sombid for me can be a shriek, but let's try to do something, if it is like a sump it has to be some bearing that has to do with that belt, you can forburn the following, take out the strap of elects (alternator, air, etc) if you only have a problem and give a touch of start to the car and listen if the noise disappears, we disappear. Distribution of a beginning, if it disappears, then you have turned the pulleys by hand those that are not with a strap and see which one of all probates that noise and already ientific and repairs, let us know how you go.

I am solved by the noisy hehe I did what they suggested but it was still heard that I decided to change the time band. since it was very burned or dry.
Thanks for answering.