1. Eardrum Membrane that vibrates the bones of the middle ear.

2. Cochlea Fluid-filled structure of the inner ear that contains hair cells.

3. Intensity Amount of sound energy that flows through a given area at a given time Beethovoven’s music had a lot of intensity.

4. Loudness The way the brain perceives the intensity of a sound. IPods are usually played loudly.

5. Frequency Frequency is a measure of the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is the duration of one cycle in a repeating event. So the period is the reciprocal of the frequency.measure timedurationcyclereciprocal

6. Pitch The highness or lowness of a sound. Opera singers can have a high pitch or a low pitch.

7. Ultrasonic waves Sounds with frequencies above 20,000 Hz

8. Doppler Effect The change in pitch of a sound caused by motion of either the sound source or reciever.

9. Noise noise means unwanted sound or noise pollution. soundnoise pollution Kids can make a lot of unwanted noise.

10. Quality Difference between sounds of the same frequency caused by overtones.

11. Music A combination of sounds and distinct pitches following a specified pattern.

12. Overtones Multiples of the fundamental frequency

13. Resonator The part of the violin that amplifies the sound of the strings

14. Echo A true echo is a single reflection of the sound source. The time delay is the extra distance divided by the speed of sound.speed of sound If so many reflections arrive at a listener that they are unable to distinguish between them, the proper term is reverberation reverberation

15. Reverberation Unpleasant echo effect caused by many by different circumstances (happens in caves),

16. Acoustics The study of sound

17. Echolocation Finding objects by emitting sound waves and interpreting the reflected sound.

18. Sonar Used to locate objects underwater by reflection of sound waves.