iPad buzzes
iPad makes buzzing sound
Question marked as
Are you sure the noise is from the iPad itself - and not, possibly, from one of its speakers?
If the noise is definitely from the “internals” of the iPad, then the issue could be with one of the high-frequency power converters mounted on the logic board. Electronic power converters under high load can occasionally become mechanically noisy (a phenomena most noticeable with laminated inductor components).
Whilst annoying - and not “normal” - unless you are suffering other issues, this might not be a fault that should be cause for concern.
However, if you are within your warranty period, as a precautionary measure, I would recommend returning to your retailer. If the purchase was very recent, then I’d be inclined to insist upon a “new” replacement (if the consumer laws in your part of the world support this remedy). If returning to Apple outside of your 14 day “unconditional return” period, Apple might offer you an exchange for a “brown box” reconditioned unit - that, in theory at least, should be “as new”.
I hope this proves to be helpful.