Very Strange Noise

[Jaguar Man]

I could really do with some help. I have owned cars for more years than I care to remember but our DS3 has developed a very strange noise, which I have never heard before, with the following characteristics.

1. The noise is a random event which can be on start up or whilst running and can also go away whilst the engine is still running
2. It can have various volume levels.
3. The noise appears to come from behind the dashboard and can be heard in the car but only just from under the bonnet
4. The noise is engine speed related and is a high frequency whirring type of sound

Does anyone have any ideas? I have a video which shows an ‘event’ but the website will not allow the MOV file to be uploaded. If someone is interested in this, I would be happy to email the MOV file if you would like to email me at nigeldodman@aol.com