1. Sound How does the ear work?

2. What does the ear do? http://www.acoustics.salford.ac.uk/schools/ index1.htm Lesson 1 page 5 It senses the frequency (pitch) and amplitude (volume) of sounds. What units do you measure volume in? What is frequency? What units do you measure frequency in?

3. The ear The ear senses the frequency (pitch) and amplitude (volume) of sounds. Volume is measured in decibels (dB) Frequency is the number of waves per second and it is measured in Hertz (Hz). The freuqency of the wave below is ____ 1 Time (s) Make notes

4. Step 2: The ear. Now draw the ear and explain how it works.

5. Step 2: The ear Watch this video and think about the questions. http://www.neok12.com/php/watch.php?v=zX6 d5740785f007905650259&t=Sound http://www.neok12.com/php/watch.php?v=zX6 d5740785f007905650259&t=Sound 1.Which part of the ear changes the sound waves into an electrical signal? 2.Which part of the ear passes the vibrations from the eardrum to the cochlea? 3.What are the three semi-circular canals for? 4.What is volume measured in? 5.How can you become temporarily deaf? 6.How can you become permanently deaf? Do the worksheet

6. Check your answers. 2.Which part of the ear changes the sound waves into an electrical signal? 3.Which part of the ear passes the vibrations from the eardrum to the cochlea? 4.What are the three semi-circular canals for? 5.What is a noise? 6.What is volume measured in? 7.How can you become temporarily deaf? 8.How can you become permanently deaf? 2. The hairs in the cochlea - cilia 3. The ossicles 6. Decibels 4. Balance 5. An unpleasant sound 7. Listening to too loud noises (> 80 dB) for some time. 8. Listening to too loud noises (> 80 dB) for a long time or a very loud noise (>120dB) for a short time.

7. Step 5: Answers. 9.Why do you become deaf? Describe what happens to the ear? 10.Put these noises on the scale below: normal conversation, jet plane, thunder, lorry, bird’s singing, motorbike, 11.What volume can cause somebody to become permanently deaf? 12.How can you protect your hearing? 13.What is the hearing range of a human? 14.What frequency is ultrasound do you think? 16 to 20,000 Hz 9. The hairs in the cochlea are damaged or the ear drum can be perforated (has holes in). 11. Above 120 dB ?? 10. Jet plane – 130dB; thunder – 115 dB; lorry – 100dB; motorbike – 85dB ; normal conversation – 45dB; bird‘s singing – 25dB 12. Above 120 dB

8. What‘s your frequency range? Use a sound metre to measure the volume of different things.

9. Frequencies which other animals can hear What frequencies can you hear?