No, the “speech banana” is not a cutting edge banana-shaped hearing instrument. It’s a reference to the distribution of sounds in an audiogram – a visual rendering of an individual’s hearing acuity within a range of volumes and frequencies. Audiograms are plots of sound frequency (on the x axis) and loudness (on the vertical axis). In a hearing evaluation, each test sound is defined by its volume and frequency and can be graphed to create a chart.
The term ‘speech banana’ arises from the banana-shaped group of points on the audiogram that develops when human speech is examined. Nearly the whole alphabet and most letter combinations (such as ch, sh, th and ng) cluster into the speech banana range. The main exceptions are the letters q, w, x, and y.
The speech banana is extremely important because it includes most of the sounds of human language which is vital for our ability to communicate with each other. People with normal hearing, can also hear lots of sounds outside of the banana such as high frequency glass breaking or low frequency thunder. Hearing loss often strikes this speech banana area, resulting in individuals having difficulty hearing the letter combinations ng, th, sh and ch.
As a result, hearing specialist are most concerned with hearing impairment that develops within the area of the speech banana. Irrespective of whether the person is old or young, if they are having difficulty hearing sounds within that frequency and volume range, they are almost definitively having difficulty hearing speech, and therefore have problems communicating properly with others.
The range of spoken sounds encompassed by the speech banana is so vital to communications, that a number of school districts require hearing assessments using audiograms to detect hearing losses in this region. This is also a primary reason why it’s very important to have your hearing aids,if you own them, correctly programmed and tuned by a professional audiologist or hearing specialist, who can make sure that you are hearing sounds within this speech banana area clearly. Make certain you don’t miss out on the human speech in your life by scheduling a hearing evaluation and professional audiogram if you suspect an issue.