Hearing is considered to be within normal limits
This loudness is measured in a scale called decibels (dB). Any points that are heard at 20dB or quieter are considered to be within the normal range.The lower down the graph the points are plotted, the worse the hearing. The different shaded areas indicate the different classifications of hearing loss.he audiogram below shows the sounds have to be made louder before they are heard in the high frequencies (the right side of the audiogram), leading to a slope on the audiogram as seen below. This audiogram shows normal hearing up to 1KHz (mid frequency) and a mild hearing loss in the mid to high frequencies.