Ultrasound

• Human can hear sounds with frequencies ranging from 30 Hz to 20000 Hz (20kHz)
• Ultrasound:

  • Sound with frequencies higher than 20 kHz up to 100 kHz
• When a wave encounters a boundary between two media, part of the wave is reflected, part is absorbed and part is transmitted
• Using this fact humans have built machines which use ultrasound to produce images
• Widespread applications in the medical field