1. Diffraction of Sound Waves By: Adams Daramy

2. Diffraction Beam of light spread out=>passes through medium -Accompanied by interference between the wave forms produced Wave bends when it passes around an edge/through a slit Change in the direction of waves as they encounter opening/barrier in their way More pronounced with longer wavelengths:

3. Sound Wave Wave of compression/rarefaction Speed of Sound Wave (c)=wavelength/period of time -measured in meters per second Can be heard around corners and barriers -due to diffraction and reflection of sound

4. Reflection of Sound Waves Leads to either an echo or reverberation Reverberation-Prolongation of sound; resonance Law of Reflection: angle of incidence equals angle of reflection

5. Sound Radiation in Woodwind Instruments -Effects of Diffraction Standing waves in a tube, compressions/rarefactions, are longitudinal From closed tube end, waves will be reflected > due to diffraction Amount of diffraction depends on ratio of wavelength to bore diameter Waves pass through large opening with minimal disturbance -large proportion of sound energy reflected from open end

6. Acoustic Impedance Ratio of pressure fluctuation to particle velocity: Z=p/v Volume Velocity/Discharge-the particle velocity times the tube area A. Z=z/A=p/U When waves meet at open end, encounter sudden change in impedance