10th physics -2
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Loudness refers to the perceived intensity of sound and is measured in units of bels or decibels. Loudness is directly proportional to the logarithm of sound intensity, meaning it increases logarithmically as sound intensity increases. The factors that affect loudness include the amplitude, area, and distance from the vibrating source. Sound level is a measure of the intensity level of a sound compared to the faintest audible sound and is measured in decibels. Pitch is defined as the rate of vibrations producing a sound and is determined by frequency, with higher frequencies producing higher pitches. Loudness and pitch both increase with increasing amplitude and frequency of the vibrating source, and decrease with decreasing amplitude
10th physics -2
- 2. Loudness of sound 1) Loudness is the characteristics of sound by which loud and faint sounds can be distinguished. 2) Magnitude of sensation produced on the ear by a sound is called its loudness
- 3. Sound energy passing per second through a unit area held perpendicular to the direction of propagation of sound wave is called intensity of sound. I = E / A
- 4. Loudness (L) of a sound is directly proportional to the logarithm of Intensity (I) . L ∝ log I L= K log I Where K is a constant of proportionality
- 5. Loudness is the characteristics of sound by which loud and faint sounds can be distinguished. Factors : Amplitude of Vibrating Body Area of vibrating body Distance from the Vibrating body
- 6. Sound Level Difference between loudness of sound and the loudness of faintest sound is called Intensity level of any sound . Sound Level = 10 log( I / Io) Sound level = 10 log ( I – Io) The unit of sound level is bel . The smaller unit of intensity level is decibel. 1bel = 10dB Bel If the given intensity of sound is 10 times greater than the faintest audible sound then the unit of sound level becomes equal to 1 bel.
- 7. The Units of loudness are bel or decibel (dB). 1bel = 10 dB So loudness is always measured in terms of intensity level. We use logarithmic scale because Logarithmic Scale gives us the easy Calculation to identify the intensity of sound The loudness (L) of a sound is directly proportional to the logarithmic of intensity. L ∝ log I L= K log I Where K is a constant of proportionality
- 8. Frequency Frequency is the number of waves passing through a point in unit time. Pitch The Pitch is simply the rate at which vibrations are produced Pitch depend upon the frequency . A higher pitch means a higher frequency. There is no as any difference in pitch and frequency. Pitch show Qualitative Nature of Sound Frequency Show Quantitative nature of sound
- 10. Effect of Amplitude on Loudness 1. By increasing amplitude of Vibrating body , the loudness also increase . 2. By Decreasing the amplitude of vibrating body , the Loudness also decrease .
- 11. By increasing frequency of the vibrating body , The Pitch also increase . By Decreasing Frequency of the vibrating body , the pitch also decrease.