Noisy water pump from rainwater tank

Hi,
We've just moved into our new house. Our tanks are connected to the toilets and washing machine. I've noticed everytime we flush it is quite noisy. I'm worried because it is quite close to the fence and neighbours' outdoor area. Does anyone have any ideas for noise reduction?

I assume that it is an external pump. If so, does it have a well ventilated cover?

Is it a turbine, jet or centrifugal pump?

What does it sound like? Not a rumbling like gravel going through it I hope. If so, how is the suction hose attached to the pump, have they fitted a 90 degree elbow to the pump at the end of the suction hose?

Thanks for your reply. I have to check what type of pump it is. The sound is like an electronic humming. It does have a cover over it which has spaces and gaps so I assume it is ventilated.

A turbine pump has a higher pitched sound than a centrifugal pump...it sounds very 'busy' and fast.

A jet pump is a tad noisier than an equivalent pressure pump but it is not high pitched, more of a dull water sound. That is normal because jet pumps have greater suction than the usual pressure pumps and the noise is the result of how the additional suction is achieved.

The noise to be alarmed about is a rumbling sound like broken marbles because that indicates cavitation.

The pump should be on a solid base but they should also have dampers under their support base to eliminate resonance. If it is on a concrete base, just put a rubber mat under it and see what happens.

Thanks for the advice, I will try the rubber mat.