Noise from kitchen sink tap

Hi,

Just wondering if anyone can advise on a noise I get from my kitchen tap.
When i turn on the tap and the water runs, the sound of the water is a loud "shhhhhhhh" or "chhhhhhh" sound, sort of a high pitched foaming sound like .
Seems to come from the pipe system rather than just the mouth of the tap.

It's not annoying, but it's pretty audible from other parts of the house, and tends to wake the baby up (when he is in his bedroom) from his sleep.

Not sure if something can be done without major cost. The tap has a mixer with the separate flexi hoses running to hot & cold water respectively. Cheers.


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