Image Number 10 for United States Patent #5952618.
An acoustic conduit includes an outer tube and two independent inner tubes. The outer tube is formed of a first material having a first density. The inner tubes are formed of springs of a second material having a second density and each creates an acoustic chamber. The first and second materials are chosen so that the second density is greater than the first density. The acoustic conduit may be used as, for example, a stethoscope tube.