No, the “speech banana” is not a super fruit that improves hearing or is a reference to that classic vaudeville comic skit that goes, “Speak up…I can’t hear you…I’ve got a banana in my ear.” The “speech banana” is a distinctive design appearing on an audiogram. Audiograms are graphs of sound frequency (on the horizontal axis) and volume (on the vertical axis). During a hearing evaluation, each test sound is defined by its volume and frequency and can be plotted on a chart.
Where the curious term derives from is the fact that if you analyze the sounds of human language (termed phonemes) on an audiogram, they tend to group into a banana-shaped region of the graph. The spoken sound of all of the letters in the alphabet, except q, w, x, and y, cluster within the speech banana, as do the widespread letter pairs th, ch, sh, and ng.
For those who have normal hearing, you can hear sounds inside this area, but can also hear higher-frequency sounds such as a mosquito or a glass breaking and lower-frequency sounds such as machinery or thunder. However the sounds that are most critical to our communications with other people are the sounds we generate when talking. Individuals with hearing problems often have difficulty hearing certain vowels and the letter combinations ch, sh, th and ng.
This is the reason hearing professionals are most focused on hearing loss within the range represented by the speech banana. If you are having trouble hearing sounds within this range, regardless if you are young or old, you are most likely having difficulty hearing other people properly, and may have trouble interacting with them.
The speech banana is considered so crucial to healthy hearing that many school districts have mandated audiograms for their students in order to identify and treat hearing impairments early, espcially those affecting communications. This is also one of the reasons why it’s very important to have your hearing aids,if you own them, properly programmed and “tuned” by a professional hearing specialist or audiologist, who can make sure that you are hearing sounds inside this speech banana area clearly. Make certain you don’t miss out on the human speech in your life by requesting a hearing evaluation and professional audiogram if you suspect a problem.