I have lived in a house that has low water pressure because we are on a well/booster pump system and the booster pump is 25′ below the the level of the house.  The pipes whistle when you are in the shower and when the booster finally kicks in, the whistling goes away.  This really hasn’t bother us too much , but my chiropractor complained that his track home does the same thing even when he flushes a toilet. 

Do Any of you’all know how to correct this problemand/or explain the real cause?   My “uneducated” thought is to increasethe pressure in his regulator or replace it with a new one.  Is this the correct thinking.  Any an and all input would be appreciated.                                              -Brian