What is an audiogram?
The audiogram is a picture of your child’s hearing. The softest sounds that your child can hear are charted on the audiogram. Sounds can be soft or loud and low pitched or high pitched. Both the loudness and the pitch of a sound are shown on the chart. Very soft sounds are located at the top of the chart. Very loud sounds are located at the bottom of the chart.
The loudness is measured in decibels (dB). Loudness is also referred to as Hearing Level or Intensity. Low pitched sounds, like a big drum, are located on the left side of the chart. High pitched sounds, like a bird chirp, are located on the right side of the chart. Pitch or frequency is measured in Hertz (Hz). A loud low pitched sound, like a fog horn, will be marked in the lower left corner of the chart. A soft high pitched sound, like a mouse squeak, will be marked in the upper right corner of the chart. The softest sounds your child can hear with their right ear are marked as red O’s on the chart. The softest sounds your child can hear with their left ear are marked as blue X’s on the chart. The softest levels the child can heard at each pitch are called the "hearing thresholds".
The thresholds for each ear are often different. Your child’s team will frequently refer to your child’s thresholds. The patterns formed by these thresholds are described as the degree and the shape of your child’s hearing loss.
What does the shape and degree of hearing loss mean?
The levels of the patterns on the audiogram indicate the degree of hearing loss. The degree of hearing loss refers to the average amount of hearing loss for speech sounds. The degree of hearing loss is measured in decibels (dB). For children, a mild hearing loss ranges from 20 dB to 40 dB, moderate from 41 to 60 dB, severe from 61 to 90 dB, and a profound hearing loss > 90 dB HL. The degree of hearing loss can be the same or different in each ear.
The slope or curve of the lines on the audiogram indicate the shape of hearing loss. The shape of the hearing loss could be flat, or about the same for all pitches. The hearing loss could be slightly worse in the high frequencies, or gradually sloping. It is very common for a hearing loss to be a little worse for the high pitches than the low pitches.
Another common pattern is a "cookie-bite". In this pattern the hearing loss is worse in the middle of the speech sounds than it is at either end. The degree and shape of the hearing loss indicates how well your child can hear without hearing aids. A child with a mild flat loss can hear normal conversation in quiet situations when you are close by. A child with a moderate sloping hearing loss will hear talking when it is louder than normal. A child with a severe hearing loss with a cookie bite shape will be able to hear the TV if it is turned up very loudly. A child with a profound hearing loss will be able to hear very loud environmental sounds like the siren on a fire truck.
Most hearing loss will interfere with hearing the speech sounds and the development of speech and language skills of a child.
Phonak acknowledges the permission and assistance of the following organizations for their expertise in this portion of our website:
- The Better Hearing Institute
- The Infant Hearing Guide