Usually, the sound presents for many reasons. High pressure, low pressure, and auto shut failer after 5 years.
Incoming High pressure water is more than 75 psi, add pressure reducer. Part #105229
Low incoming water pressure less than 50 PSI check city water incoming pressure to the system membrane housing inlet. if it's less than 50 PSI check the pre-filters as they might be clogged with dirt. The pressure is well and more than 50 PSI check the membrane if it's more than 2 years replace it. if all above is good and city water is less than 50 PSI then you have to add a booster pump to increase the pressure by more than 60 PSI
Check the flow restrictor if partially blocked with the dirt during the use by Appling water pressure from the opposite side.
If the auto shut-off valve is older than 7 years its better to change it by searching item #105111