High pitched whistle on 111s

[jay50A]

Hi, This is a bit of a difficult one to explain??!! But basically when I turn the ignition key on, but before you start the engine, you can hear a high pitched whistle coming from the engine bay (Possibly the fuel pump??),
It has always done this since I've had the car and the noise stops after about 5-10 seconds, i'ts as if something is priming itself? But just recently the noise has been coming back again after I've started the car and stays on until the engine is turned off??? I'ts more like an electrical noise?? Very high pitched, and very annoying! Has anyone else experienced this??
Thanks in advance.

[Bill K 111]

It's the fuel pump. Although they're never usually loud enough to comment on. Perhaps yours is on it's way out?