“Speech bananas” aren’t morning snacks for hearing specialists.
What the term “speech banana” represents is a distinct pattern found in the data of an audiogram, which is a graphical chart used to measure an individual’s hearing proficiency within a set range of frequencies and volume levels. In an audiogram, you usually see the frequency (which is measured in Hertz) on the horizontal axis, and the loudness ( in Decibels) on the y axis.
The phrase ‘speech banana’ comes from the banana-shaped collection of dots on the audiogram that develops when human language is analyzed. Almost the whole alphabet and most letter combinations (such as ng, ch, sh and th) cluster into the speech banana range. The main exceptions are the letters w, x, y and q.
People with normal hearing will also hear sounds outside this speech banana range – including higher-frequency sounds such as birds chirping or a glass breaking and lower-frequency sounds such as tubas or machinery – but the sounds most vital to human communication are the sounds of other people talking. Hearing loss often affects this speech banana area, resulting in individuals having trouble hearing or understanding the letter combinations ch, sh, th and ng.
When hearing loss impacts the frequencies and volumes within the speech banana it interferes with person-to-person communications. This is exactly why hearing specialists and audiologists will typically focus on that range. If you are having issues hearing sounds within this range, regardless if you are young or old, you are probably having difficulty hearing people properly, and may experience difficulties interacting with them.
This is one of the reasons why hearing tests using audiograms are required in the schools of several states – to detect possible hearing difficulties at an early age, when they can be easily corrected. Because this range of sounds is so critical to human communications it is the range that most hearing aids are programmed and adjusted to perform best in. If you have any questions about your hearing in the speech banana range, whether you wear hearings or not, give us a call.