Sound

1. Types of sound

1.1. ultrasonic sound - (+ 20,000hz) infrasonic sound -(- 20hz) audible sonud - (20 to 20,000hz)

2. Organs involved in sound production

2.1. eardrum , windpipe, layrnx,inner ear, middle ear & outer ear.

3. Noise pollution

3.1. causes : 1.honking 2.telivision 3.sound producing gadgets measures : 1.silent devices 2.planting trees

4. Terms related to sound waves

4.1. 1.Amplitude 2.Time period 3.Frequency

5. Instruments

5.1. 1.stringed instruments - violin 2.percussion instruments - tabla 3.wind instruments - flute

6. Characteristccs

6.1. 1. sound is form of energy 2.produced by a vibrating object 3. needs medium to propogate

7. Quality of sound

7.1. 1.pitch - depends on frequency 2. loudness - depends on amplitude

8. Disturbance

8.1. Non periodic - Noise periodic - Music