Frequency of Hidden High Frequency Hearing Loss in Patients with Idiopathic Tinnitus

Abstract

: Tinnitus is a hallucination of sound, usually described as ringing and buzzing in the ears. Many factors are known to cause tinnitus but sensorineural hearing loss (SNHL) was found to be the most common. The objective of this study is to determine the actual frequency of idiopathic tinnitus and frequency of hidden SNHL in patients presenting with idiopathic tinnitus without hearing loss. This cross sectional study was performed at PAF Hospital Islamabad between December 2018 to Dec 2022. All the patients that presented with tinnitus without any subjective complaint of hearing loss were included in the study. All the possible causes of tinnitus were ruled out before labelling it idiopathic tinnitus. PTA was performed in all patients. The number of patients was calculated who had tinnitus without hearing loss on PTA. These were the patients with idiopathic tinnitus (G Hi ). Then these patients were tested for hearing loss on PTA in frequencies higher than 8000 Hz to find out hidden hearing loss. In these patients, the number of patients having hearing loss in frequencies higher than 8000 Hz (G H ) was calculated. These patients (G H ) were removed from the list of idiopathic tinnitus and were the patients with hidden SNHL. In this way the actual frequency of idiopathic tinnitus (G i ) was calculated. The results were tested biostatistically using SPSS 20. Chi-square, simple t test and Fisher’s exact test were applied. The significance of results was calculated. Out of 100 patients, 65 were female and 35 were male. The mean age was 28.9±11.7 years. On audiometry only 10% patients had hearing loss in frequencies usually tested during audiometry (500Hz-4000Hz), Gs. All of these were males (100%). Routine audiometry was normal in the remaining 90% of patients (G Hi ). When these patients were tested in frequencies higher than 8000 Hz, out of these 90% patients, 55% of the patients had high frequency hearing loss (>8000 Hz), (G H ); this is the hidden hearing loss. P values were < 0.001and 0.75 on Fisher’s exact and Chi-square tests, the results were found to be significant. It is often seen that patients with idiopathic tinnitus develop SNHL later in life. Therefore, tinnitus can be considered as an early symptom of hearing loss. The actual frequency of idiopathic tinnitus (Gi=45%) is far less than documented, in most of the cases there is hidden SNHL.