About sound and decibels

Sound is actually short for sound pressure level, or SPL, Steve Orfield said. It is measured in decibels, or dB, around which there are misconceptions. A few facts:

• Zero decibels is not the absence of sound but the quietest thing an infant can hear. (Infants have the most sensitive hearing.)

• Many animals have better hearing than us, including owls and dogs; Chihuahuas can hear to almost minus-30 decibels.

• The sound level in the average bedroom with seemingly nothing going on is about 30 decibels, Orfield said.

• Noise levels double with every decibel increment of 10, so 60 decibels is twice as loud as 50, and 90 decibels is 16 times louder than 50.