I had a patient recently who reported having had a couple of hearing tests completed in the past year and a half and wondered why he would require another hearing evaluation before being fit with hearing amplification. The answer is for pure tone testing, a test within the past 6-12 months can be sufficient, however, pure tone testing is only a small portion of a hearing evaluation.
Pure tone testing (beep testing) is a test where you are presented with a series of beeps at different test frequencies to determine the softest level at which you can hear a sound. This is an integral portion of the test battery but alone provides little information.
When you add speech testing to the pure tone test results you can gain more knowledge on the function of the auditory system. Speech testing is vital to provide a cross-check for verifying if the results given during pure tone testing are accurate and can provide insight into the function of the inner ear, hearing nerve, brainstem, and speech centers in the brain. Speech testing is not an MRI or CT scan, so it does not give an image of any structures, but poor speech test scores can sometimes be a flag that something may be off in one or more of these areas.
Speech testing can also be performed in the presence of background noise. This is often referred to as speech in noise testing (a clever name I know). Speech in noise testing can be a fantastic tool for how a patient processes speech in a more realistic or real-world scenario. Let’s face it, pure tone beep testing is great to identify how soft you can hear but it provides little information into how you process and interact with the world around you.
The patient mentioned in the first paragraph scored a mild to moderate hearing loss on pure tone testing and scored in the 80% range on speech identification but when presented with speech in noise he scored more like someone with a severe or profound hearing loss. His chief complaint was a poor understanding of noise. But without adding speech in noise testing it would not look like as big of an issue.
Using a full test battery is the best way to diagnose and understand what is happening in the auditory system. So before you trial a pair of hearing aids make sure to ask if you have had at least pure tone testing, speech testing, and speech in noise testing because if you have not there may be a piece of your hearing puzzle missing and you may not be as successful.