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The Hearing Range of Humans

Science: KS3, topic 3.3.14

Hearing Range of Humans

Humans can only hear a certain range of sound frequencies. Frequency is measured in Hertz (Hz).

Sound frequencies

Sound frequencies

  • A hearing range or auditory range is the range of frequencies that can be heard.
  • Frequency is the number of sound waves that happen in one second.
  • Frequency is measured in Hertz (Hz).
  • The frequency affects the sound's pitch.
  • A high pitched sound means the particles are vibrating very quickly.
  • Speakers that are not tuned correctly can make a high pitch sound.
Human hearing range

Human hearing range

  • Humans are able to hear in the range of 20 Hz (low frequency) to 20,000 Hz (high frequency).
  • We call sounds above 20,000 Hz ultrasound. Humans are unable to hear these sounds.
  • Sounds that are very low frequency below 20Hz are called infrasound.
  • All animals hear different auditory ranges for instance:
  • Cats: 50Hz – 64,000Hz.
  • Dog: 67Hz – 45,000Hz.
  • Whale: 1000Hz – 123,000Hz.
Infrasound uses

Infrasound uses

  • We are able to detect infrasound from volcanic eruptions.
  • Large animals, such as elephants and whales, are known to use infrasound to communicate with each other.
Ultrasound uses

Ultrasound uses

  • Because sound waves are harmless, ultrasound can be used to scan an unborn baby during pregnancy.
  • Ultrasound is used to break down kidney stones and cleaning teeth.
  • Ultrasound can shake dirt off objects when they are placed in a liquid.
  • It can be used in physiotherapy to treat sprains.
  • We can also detect fish by SONAR (SONAR is actually an acronym for Sound Navigation And Ranging).
Animals using ultrasound

Animals using ultrasound

  • Cats, dogs and bats use ultrasound for communication or navigation.
  • Dolphins and bats use ultrasound for echolocation.

Test yourself on The Hearing Range of Humans

  • A sound source vibrates very quickly. What pitch does this produce?

  • Which of these is NOT a use of ultrasound?

  • Which of these are true of sounds beyond our auditory range?

  • A cat can hear up to 64,000Hz and a human can hear up to 20,000 Hz. Which can hear higher-pitched sounds?

  • A whale can hear from 1000Hz and a human can hear from 20 Hz. Which can hear lower-pitched sounds?

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