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.
The hearing level is quantified relative to 'normal' hearing in decibels (dB), with higher numbers of dB indicating worse hearing. Hearing loss can be graded as follows: 1  Normal hearing: less than 25 dB in adults and 15 dB in children. 2  Mild hearing loss: 25-39 dB. 3  Moderate hearing loss: 40-69 dB.4  Severe hearing loss: 70-94 dB.earing loss can be graded as follows: 1  Normal hearing: less than 25 dB in adults and 15 dB in children. 2  Mild hearing loss: 25-39 dB. 3  Moderate hearing loss: 40-69 dB. 4  Severe hearing loss: 70-94 dB.