Mechanical noise is frequently a problem for condo owners and source of noise complaints. Recently I have received several requests from clients living in hi-rise condominium buildings complaining about “hum” or “vibration” mechanical noise in their apartments. The clients contacted me, after first dealing with the building management. They asked me to do a noise test. The management told them that the noise is not audible to them, or that the noise is “normal”. The clients ask me what level of mechanical noise is “normal”.