We really need a technical person to confirm this, but ISTR an issue that came in when carbon fibre brakes began to be used. Apparently the life of these brakes was best when they were used less often but harder - and so a practice developed of airlines specifying the use of idle reverse only unless conditions dictated otherwise. Normally, there were no safety implications in this, but IIRC this practice was a factor in the QF overrun accident at BKK, because idle reverse only was selected when more reverse thrust was really needed in the circumstances.
If idle reverse was an SOP for your flight, that may explain why there was little noise. You also have to remember that the newer generations of engine are ever more quiet than their predecessors, which can also mask the amount of thrust (forward or reverse) actually being used. Sometimes the only way of knowing for sure whether the reversers have been deployed on landing is to stick your face in the window and have a look.