Introduction To Sound

Noise
We feel pleasure to hear music or chirping of birds in the garden (Figure 8.5). Such sounds are called pleasant or musical sounds. There are some other sounds which we do not like to hear; such as sounds of heavy traffic, barking dogs, road construction machinery, hammering metal sheets, etc. (Figure 8.6). These are unpleasant sounds and are termed as noise. They are irritating, affect our ears and other body systems badly.
    
                                     Figure 8.5
    
                                        Figure 8.6
Effects of Noise on Human Health
Noise affects not only our hearing but also our health. We cannot think and work properly at noisy places (Figure 8.7). People living in noisy areas often suffer from headache, blood pressure and many other diseases. Noise makes people irritated. Noise may even disturb our nervous systems.

             Figure 8.7