To start with an attempt at weak humor, the “speech banana” is not a reference to that classic joke, “Speak up…I can’t hear you…I’ve got a banana in my ear.” Speech banana is a reference to the sounds in an audiogram – a graphical rendering of a person’s hearing ability within a range of frequencies and loudness levels. Audiograms are plots of frequency (on the x axis) and volume (on the vertical axis). In a hearing test, each test sound is characterized by its frequency and volume and can be plotted to create a chart.
The term ‘speech banana’ comes from the banana-shaped cluster of dots on the audiogram that develops when human speech is examined. The spoken sound of all of the letters of the alphabet, except w, x, y and q, fall within the speech banana, as do the prevalent letter combinations ch, sh, th and ng.
For those who have normal hearing, you can hear sounds within this range, but can also hear higher-frequency sounds such as a glass breaking or a mosquito and lower-frequency sounds such as a fog horn or thunder. However the sounds that are most critical to our ability to communicate with other humans are the sounds we produce when speaking. Hearing loss often strikes this speech banana area, which results in individuals having trouble hearing the letter combinations ch, sh, th and ng.
When loss of hearing impacts the frequencies and volumes within the speech banana it disrupts interpersonal communications. For this reason hearing professionals will often focus on that area. Whether the person is old or young, if they’re having trouble hearing sounds within that range, they are almost definitively having trouble hearing other people talk, and therefore have problems communicating effectively with others.
The speech banana is considered so vital to hearing health that many schools have required audiograms for students in order to detect and address hearing impairments early that may be affecting their ability to communicate. This is also a primary reason why it’s so important to have your hearing aids correctly programmed and tuned by a professional audiologist or hearing instrument specialist, who can ensure that you are hearing sounds inside this speech banana area as clearly as possible. If you have any concerns about your hearing in the speech banana range – with or without hearing aids – we encourage you to call and get more information.