Ears
Physics: Cambridge International GCSE Supplement, topic 3.6.2
Sound Waves and our Ears
Our ears can detect vibrations (compressions and rarefactions) and transfer the information to our brain via our auditory nerve. Our ears are sensitive to (can hear) a range of frequencies between 20Hz and 20,000 Hz.
Age
- The range of frequencies that we can hear changes with age.
- Elderly people tend to become less sensitive to sounds with a higher frequency.
Ultrasound
- Ultrasound has a frequency above 20,000Hz. Humans cannot hear sounds with frequencies this high, but other animals can.
- Dog whistles have frequencies above 20,000Hz, which is why humans cannot hear them.
- Ultrasound is also used by doctors to perform scans of a developing foetus.
Test yourself on Ears
Which of these sound frequencies can humans not hear?
Which of these is ultrasound not used for?