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.
40 dB sounds twice as loud as 30 dB and 8 times as loud as 10 dB (10 to 20 to 30 to 40 = 2 x 2 x 2 = 8). Normal hearing ranges from 0 to 20 dB in all frequencies. From here on, the assumption is that you have a sensorineural hearing loss (that you have nerve damage to the inner ear).Nerve damage, unless sudden, is permanent. For conductive hearing losses, see your otolaryngologist (your ENT physician).f all of the X's (for the left ear) and all of the 0's (for the right ear) fall above the line you just drew, you have normal hearing. If anything is below that 20 dB line, you have a hearing loss. Your hearing loss is classified according to how far down the graph the marks go, and in what freqencies the loss occurs.