Match the correct answer: a. Noise i. Pleasant sound b. Music ii. Unit of sound level c. Decibel iii. Unpleasant sound

a. Noise - iii. Unpleasant sound Noise is unwanted sound, which can disturb the peace of any person; it is an unpleasant sound. It comprises several frequencies and involves a random change in frequency and amplitude. b. Music - i. Pleasant sound Music is a pleasant sound, it also comprises different frequencies, but the frequencies are regularly or follow the periodic pattern. c. Decibel - ii. Unit of sound level Decibel is the unit of intensity of sound. Sound can measure with a device is called decibel meter. a. Noise iii. Unpleasant sound b. Music i. Pleasant sound c. Decibel ii. Unit of sound level