Period & Frequency Jan 2014 | Page 10

Name: Date: 24.1 Decibel Scale 24.1 The loudness of sound is measured in decibels (dB). Most sounds fall between zero and 100 on the decibel scale making it a very convenient scale to understand and use. Each increase of 20 decibels (dB) for a sound will be about twice as loud to your ears. Use the following table to help you answer the questions. 10-15 dB 30-40 dB 65 dB 70 dB 90 dB 100 dB 110 dB 120 dB • A quiet whisper 3 feet away Background noise in a house Ordinary conversation 3 feet away City traffic A jackhammer cutting up the street 10 feet away )1