A person can be identified by the quality of sound produced by him. The characteristic of a sound can be determined by

Options

A. amplitude
B. frequency
C. loudness
D. all of these

Explanation

To determine the characteristics of a sound that can help identify a person, we need to consider the following aspects:

1. **Amplitude**: This refers to the maximum extent of a vibration or oscillation, measured from the position of equilibrium. In terms of sound, amplitude is related to the loudness of the sound. A higher amplitude means a louder sound, while a lower amplitude means a softer sound.

2. **Frequency**: This is the number of vibrations or cycles per second of a sound wave, measured in Hertz (Hz). Frequency determines the pitch of the sound. A higher frequency results in a higher pitch (sharp sound), while a lower frequency results in a lower pitch (dull sound).

3. **Loudness**: Loudness is the perception of sound intensity by the human ear. It is influenced by both the amplitude of the sound wave and the frequency. Different people may perceive loudness differently, but it is an essential characteristic of sound.

4. **All of these**: Since amplitude, frequency, and loudness all contribute to the quality of sound, they collectively help in identifying a person by their voice.

Thus, the answer to the question is that the characteristics of sound can be determined by amplitude, frequency, and loudness, which means the correct option is **4. All of these**.