Demos by PIRA

  3B30.01Ultrasound transducers (40 kHz) as both sources and receivers.
  3B30.20Measurement of speed of sound with microphone, speaker, oscilloscope.
  3B30.30Bell ringing in a jar evacuated with pump.
  3B30.50Breathe helium, voice pitch rises; breathe SF6, voice pitch lowers.