What do phonemes, audiograms and speech bananas mean to hearing?

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If you are curious, a “speech banana” is not an audiologist’s afternoon snack.The thing that the “speech banana” represents is a special pattern shown in the data of an audiogram, which is a graphical representation of someone’s hearing proficiency inside a certain range of volume levels and frequencies. Audiograms are graphs of sound frequency (on the horizontal axis) and decibels (on the y axis). In a hearing check, each test sound is characterized by its frequency and volume and can be graphed on a chart.

Exactly where the odd term originates from is the fact that if you examine the sounds of human language (termed phonemes) on an audiogram, they have a tendency to group into a banana-shaped area of the chart. Practically the entire alphabet and most letter combinations (such as ng, ch, sh and th) fall into the speech banana range. The principal exceptions are the letters w, x, y and q.

For those who have normal hearing, you can hear sounds within this range, but can also hear higher-frequency sounds such as birds chirping or a glass breaking and lower-frequency sounds such as thunder or machinery. But the sounds that are most critical to our communications with other people are the sounds we generate when speaking. It is quite common for people to have difficulty hearing or understanding letter combinations such as ng, ch, sh and th and specific vowels.

Consequently, hearing professionals are most concerned with hearing loss that happens within the region of the speech banana. If an audiogram shows that a person has loss of hearing within the speech banana range, it is almost certain that they are having oral communication problems.

The speech banana is regarded as so important to healthy hearing that many schools have required audiograms for their students in order to identify and treat hearing problems early that may be affecting their ability to communicate. The importance of this special range of sounds is an additional reason why hearing aids need to be properly adjusted and programmed by a professional audiologist or hearing instrument specialist, to make sure you can hear the sounds of human speech clearly.Whether you currently use hearing aids or not, give us a call if you have questions about your hearing ability in the critical speech banana frequency and volume range.