High frequency audiometry: a tool to predict the development of hearing loss

ABSTRACT

Almost all the investigations related to hearing impairment revolve around management of cases after the diagnosis of hearing impairment, very few studies have focused attention around its early detection. This study focuses on the feasibility of using high frequency audiometry as a diagnostic tool in the prediction of development of hearing loss. Development of hearing loss in high frequency region, which is usually not tested in audiology clinic, may give us clue about developing hearing impairment in future. The hearing threshold level of children [aged 7-15 years], with adverse perinatal factors [study group] was compared with the children without adverse perinatal factors [control group] for frequencies between 8000-18000 Hz. The hearing threshold level of children in both groups was normal in the frequencies between 250-8000 Hz so was middle ear pressure. Comparison of mean high frequency hearing threshold between the study and control groups revealed that hearing threshold of children in the control group was significantly better between than those in the study group. This finding suggests that adverse events can affect the higher frequencies of hearing of children even when the speech frequencies do not manifest any hearing impairment. This finding may be used as a clue about the vulnerability of these children. If a threshold dip between 2-4 kHz is accepted as a sign of acoustic trauma; high frequency loss may as well be considered a pointer in the development of hearing impairment in future. To prove this hypothesis a long-term study of cases with perinatal factors manifesting high frequency hearing loss is recommended