The June 13, 2017 post entitled “A Gold Standard” elicited a nice response from Mark Ashmore:
Quite clearly Pure Tone Audiometry does not deserve to be referred to as “Gold Standard”. It is flawed as a result of outdated calibration methods, outdated hardware, poor execution and over reliance on the test by too many. Having said that, the concept, which enables an objective measurement of a subjective sensation, is as brilliant now as it was seventy years ago.
PTA doesn’t measure “hearing” though. It measures ability to receive a signal which is a one part of “hearing” – the other parts being how the signal is transmitted to the brain and then interpreted. In short, it may not predict cochlear problems too well but that’s not what it’s supposed to do. From the point of view of determining whether a person will benefit from a hearing aid though this is hardly problematic – a hearing aid is essentially an amplifier and (leaving aside the exceptions to the rule) people with normal thresholds are unlikely to benefit from amplification and people with reduced thresholds will.
In answer to the authors question we move forward by ensuring PTA standards are re visited and as a result the test becomes more reliable, use more realistic language regarding what PTA is and how it fits into the test process and get the message across that provision of the hearing aid is just a small part of a successful fitting.
Essentially, Mark and I agree on pure tone testing and its necessity although I cannot agree on pure tone testing being currently “brilliant”. It might have been the “gold standard” then, but only because it was the only option.
Consider that, if gold were as common as iron or most other metals, it would not hold the value that it does. That is, there is an inverse, linear relationship between commonality and value. As “common” increases, value goes down. One can also say that Pure Tone testing has the same value as it did in the 1940s or earlier at its inception, and had our knowledge of the ear and hearing stayed fixed in the 40s and 50s, the test could stand as the state of our knowledge. But progress has left such elementary testing in the dust. While still of value in a basic manner, it has become as common (and only slightly more useful) as any mineral of little value.
In the hands of clinicians who realize the usefulness as well as the limitations of pure tone testing, the tests provide information, albeit limited. As the sole indicator of rehabilitative need, and the sole “proof” of successful mediation of hearing loss, pure tone tests are of minimal usefulness.
I bet few of us have ever transacted anything by paying in gold. The US went off the “gold standard” about 1000 years ago, or at least 1933. Any currency does not have to be backed up with anything other than user confidence. Think “bitcoin”. Now, consider if we wish to link future consumer confidence in the value of audiology to the value of pure tone tests alone.
Thanks to Mark for a provocative response.
feature image from youtube