To begin with an attempt at weak humor, the “speech banana” is not related to that classic joke, “Speak up…I can’t hear you…I’ve got a banana in my ear.” The thing that the phrase “speech banana” refers to is a distinct pattern shown in the data of an audiogram, which is a graphical representation of an individual’s hearing abilities inside a set range of frequencies and volume levels. In an audiogram, you usually see the frequency ( in Hertz) on the x axis, and the volume level or loudness (measured in Decibels) on the vertical axis.
The phrase ‘speech banana’ comes from the banana-shaped group of dots on the audiogram that is produced when human language is examined. The spoken sounds of most of the letters of the alphabet and the letter combinations ch, sh, th and ng all cluster in this particular area.
The speech banana is important because it encompasses nearly all of the sounds of human language which is essential for our communications with each other. Individuals with normal hearing, can also hear lots of sounds outside of the speech banana such as high frequency leaves rustling or low frequency thunder. It is quite common for individuals to have trouble hearing or understanding certain vowels and letter combinations such as ch, sh, th and ng.
Because of this audiologists are most concerned by hearing loss within the spectrum represented by the speech banana. If an audiogram reveals that a person has hearing loss within the speech banana region, it is almost certain that they’re having oral communication difficulties.
That is one of the reasons why hearing tests using audiograms are mandated in the schools of many states – to identify possible hearing difficulties at an early age, when they can be easily solved. The importance of this particular range of sounds is also why – if you use hearing aids – you should have them properly adjusted and programmed by a qualified hearing specialist or audiologist, to make sure you can hear the sounds of speech clearly.Make certain you don’t miss the conversations in your life by requesting a hearing evaluation and complete audiogram if you believe there is an issue.