In primary care and clinical settings, readily accessible and reliable methods and tools are needed to give patients initial evaluations. Checking for hearing loss is no exception. As of now, tuning fork tests — namely, the Weber and Rinne tests — are used to determine whether patients show signs of normal hearing or conductive hearing loss (CHL). Through these tests, vibrations from the tuning fork would be expected to lateralize to the affected ear for patients with CHL. However, in many clinical settings, tuning forks are not readily available or accessible, demonstrating a need for another test that can accurately detect CHL in these low-resource settings. Following reports that patients with CHL hear their own hum echoing more loudly in their affected ear, this study aims to formally study whether humming can, in fact, be used as a reliable alternative to the tuning fork to assess for conductive hearing loss.

The Weber and Rinne tuning fork tests were performed on the patients before initiating the hum test. The Weber test is performed by striking the tuning fork and placing it on the patient’s forehead or front teeth. The patient will then report which side, if any, they hear the vibration of the tuning fork louder on. The Rinne test is performed by striking the tuning fork and placing it on the mastoid bone directly behind the patient’s ear, testing for bone conduction. The patient is asked to report when they stop hearing the vibration, at which point the tuning fork is moved directly next to the ear canal. The patient is then asked whether they still hear the tuning fork — testing for air conduction — to ultimately determine whether air conduction is greater than or less than bone conduction. The results of the tuning fork tests were later compared to the results of the hum test.

During the hum test portion, patients were asked to let out and hold a low-pitched hum, high-pitched hum, and a “normal” or medium-pitched hum. Patients were then asked to report which ear they heard their voice echoing louder in during each hum. It was important to note whether said ear was their ipsilateral or contralateral side. The sound intensity (in decibels) and frequency (in hertz) of each hum were recorded as well. 

Using the Weber test as a baseline since it is the clinical standard for CHL testing and performed significantly better than Rinne, the hum test was not quite as accurate as the Weber test but was more accurate than the Rinne test. The Weber test predicted CHL correctly in 76% of the cases, while on average, the hum test predicted CHL correctly in 57% of the cases. 

These results demonstrate that in low-resource settings without reliable access to tuning forks, the hum test can be used as a viable alternative to tuning fork-based tests to predict the presence of CHL in patients.