What exactly is "normal hearing"? Typically, normal hearing falls within the range of about -10 dB to 15 dB for children, and 0 dB to 25 dB for adults.

Ranges of hearing sensitivity, like symbols on the audiogram, may vary between clinics. However, they are roughly similar.

The chart to the left shows degrees of hearing loss at these levels:

• Mild hearing loss: 25 dB to 40 dB
• Moderate hearing loss: 40 dB to 55 dB
• Moderately severe hearing loss: 55 dB to 70 dB
• Severe hearing loss: 70 dB to 90 dB
• Profound hearing loss: 90 dB and beyond