Diffraction

• Diffraction is the bending of waves as they pass as obstacle's edge or pass through an aperture
• The amount of sound spread is dependent on the size of wavelength (λ) and the width of the obstacle (d)

  • if the width is roughly equal to or less than wavelength, significant diffraction occurs -> leads to difficulty pinpointing the source of low frequencies
  • if the width is larger than the wavelength, limited diffraction occurs
• Frequency is inversely proportional to wavelength

  • sounds of high frequencies have shorter wavelengths and are diffracted less, meaning that they are more directional and are easier to determine direction hence being necessary in ultrasounds
• Ultrasounds are used for sonar and motion detectors as diffraction is limited thus travelling to and from with little spread
• Low frequency sounds have a larger wavelength, causing them to readily fill a room and are used in setting up stereo surround sound systems