Reactance (X) Two components Due to mass (Xm) Greatest at high frequencies Due to stiffness (Xs) Greatest at low frequencies 1

2

Total Impedance [ R2 + (Xm – Xs)2 ] Z = Impedance of a medium = Characteristic impedance [ R2 + (Xm – Xs)2 ] 3

Sound traveling from one medium to another Depending on the impedance of the two media Reflection Transmission Absorption 4

Reverberation Depends on absorption and volume. Greater the volume: Greater the reverberation Greater the absorption: Lesser the reverberation Reverberation time (RT): Time taken for a sound to reach some proportion of its original pressure. 5

Interactions between incident (original) and reflected waves Constructive interference or reinforcement Destructive interference or cancellation 6