“The loudness of sound is measured in units called decibels (dB). Everybody is on the spectrum of deafness, from normal hearing (up to 15 dB) to profound hearing loss (91+ dB):

• Slight Hearing Loss, 16–25 dB
  At 16 dB hearing loss, a person can miss up to 10% of speech when a speaker is at a distance greater than 3 feet.
• Mild hearing loss, 26–40 dB
  Soft sounds are hard to hear, including whispering, which is around 40 dB in volume. It’s more difficult to hear soft speech sounds spoken at a normal volume. At 40dB hearing loss, a person may miss 50% of meeting discussions.
• Moderate hearing loss, 41–55 dB
  A person may hear almost no speech when another person is talking at normal volume. At a 50dB hearing loss, a person may not pick up to 80% of speech.
• Moderately Severe Hearing Loss, 56–70 dB
  A person may have problems hearing the sounds of a dishwasher (60dB). At 70 dB, they might miss almost all speech.
• Severe Hearing Loss, 71–90 dB
  A person will hear no speech when a person is talking at a normal level. They may hear only some very loud noises: vacuum (70 dB), blender (78 dB), hair dryer (90 dB).
• Profound Hearing Loss, 91+ dB
  Hear no speech and at most very loud sounds such as a music player at full volume (100 dB), which would be damaging for people with normal hearing, or a car horn (110 dB).”