How to reduce sound of Exhaust fan 9 inches - sound of high speed air

Hi,

I have Vansal high speed 9" exhaust fan, its very effective but only problem is that it is causing too much noise. The noise is not coming from mount or anywhere else but from the high speed air passing through it. If I test it without fan blades, the motor is quiet. Please suggest me way to make it silent without effective its air flow capacity. I don't want to change the fan but only want to use it as I don't want to spend more money. So please don't advice to buy new costly fan. This fan is already costly because similar fan without bearing system comes on half of the price of it.

Thanks for reading and advice.

I don't know about VANSAL company, never heard of it but I think the more costly fan = more silent it is. You may cover your phone with some kind of muffler but it will resist flow somehow. If you have duct on exhaust then it will create more sound. So, you may remove the duct or add bigger duct so that there is lesser flow restriction which may result in lesser sound. Can't think of anything else , what if you can send us picture or video of the exhaust fan when its running. May be after seeing we can suggest you something better.