I posted on this very subject on Blue Angels thread 'Acoustical Sound from Shellac'.
Needles came in three types, Loud, Medium and Soft, The difference is in the thickness of the needle, with Loud being the thickest. These are not usually recommended, as they cause the most wear. A medium needle is approx. 1.5mm. diameter
The other method of volume control is to damp the sound by placing a piece of cloth into the horn, hence the expression, "put a sock in it"
To give you some idea of relative volume in my room (12x13 feet) a soft-tone needle is quite adequate, and I still occasionally 'put a sock in it' even with this!