Question

State the factors that determine the loudness of the sound heard.
a) Amplitude
b) Frequency
c) Time period
d) Pitch

Answer 1

Hint: Loudness of a sound is decided by the magnitude of vibrations of the sound while pitch of a sound is decided by how shrill the sound is. These quantities describe different properties of sound. Frequency decides the pitch of the sound.

Detailed step by step solution:
The various sounds that we listen to with our ears can have different characteristics like loudness, pitch, etc.
Loudness of a sound is defined as the amplitude or intensity of a sound. The larger the amplitude of a sound wave, higher is its intensity and louder is the sound produced by that sound wave. The units to measure the loudness of a sound are called decibels (dB). Sounds which have very high amplitude can damage our ears while those which have very low amplitude are difficult to hear.
The pitch of a sound is defined as how shrill a sound is. It is characterized by the frequency of a sound. We can hear only those sounds which have frequency from 20Hz to 20kHz. Our ear is not sensitive to frequencies higher or lower than the given range of frequencies. Higher the frequency of a sound, shriller is the sound and higher is the pitch. For example, the female voice has a higher pitch than male voice. Singing birds produce sound of high frequencies and high pitch.
Hence, the correct answer to the question is option A.

Note: Sound is different from noise in the sense that noise does not have a well-defined frequency, amplitude, loudness or pitch. Noise is basically an incoherent mixture of sounds of different frequencies and loudness.