β2−β1=10log(I1I2) β2−β1β2−β1 is the difference in sound levels measured in decibels (dB)(dB) and I2I1I1I2 is the ratio of their sound intensities measured in watts per square metre (W/m2)(W/m2) . a) A hair dryer has a sound intensity level of 70 dB, and an air conditioner has a sound intensity level of 50 dB. How many times more intense is the sound from the hair dryer than the sound from the air conditioner? b) A teacher's voice is about 80 times as intense as a 20 dB sound. What is the decibel rating of the teacher's voice?
