The condition can be fatal if left untreated, but the tetanus vaccine and improvements in treatment mean deaths from tetanus are now very rare in the UK. In 2013, there were only seven recorded cases of tetanus in England and Wales, and no deaths.
Sound pressure is measured in decibels (dB). Like a temperature scale, the decibel scale goes below zero. The average person can hear sounds down to about 0 dB, the level of rustling leaves. Some people with very good hearing can hear sounds down to -15 dB. If a sound reaches 85 dB or stronger, it can cause permanent damage to your hearing. The amount of time you listen to a sound affects how much damage it will cause.
In the audiogram below, hearing thresholds for the right ear are represented by red circles and thresholds for the left ear are represented by the blue X. In the right ear, this person has normal hearing in the lower pitches indicated by a red circle corresponding to 15 dB at 250 Hz and 20 dB at 500 Hz. Hearing thresholds in the high pitches fall into the severe degree of hearing loss, as the threshold at 2000 Hz is 40 dB, 65 dB at 4000 Hz and 75 dB at 8000 Hz.