In daily life, biological systems are usually exposed to magnetic field forces at different intensities and frequencies, either directly or indirectly. Despite negative results, the therapeutic use of the low dose magnetic field has been found in recent studies. The effect of magnetic field forces on cochlear cells is not clear in the literature.

In our study, we first applied in vivo pulsed magnetic fields to laboratory rats to investigate the effects on cochlea with distortion product otoacoustic emission test followed by histopathological examinations.

Twelve rats were included in this study, separated into two groups as the study group and the control group. The rats in the study group were exposed to 40 Hz pulsed magnetic field for 1 h/day for 30 days; the hearing of the rats was controlled by otoacoustic emission test. Also, their cochleas were removed and histochemical examination was performed by Caspase-3, Caspase-9, and TUNEL methods.

Kruskal–Wallis test

A statistically significant difference was determined (p < 0.05) when the hearing threshold of the groups obtained by using 5714 Hz and 8000 Hz stimuli were compared by Kruskal–Wallis test.

According to the results of our study, the very low dose magnetic field, which is considered to be used for various therapeutic purposes recently, can cause both auditory function defects and histopathologic damage in cochlear cells.

Histological studies in human cochleas are difficult to obtain. The study results were in rats and studies in humans, using OAE or ABR are still lacking. We think that more studies with various frequency magnetic field doses will contribute to the literature.

A significant reaction was observed in the study group, especially in the outer ciliated cells during immunohistochemical examinations by using Caspase-3 and Caspase-9 methods.

A significantly positive difference was determined in the study group, especially at the outer ciliated cells and the support cells of the Corti organ, when compared to the control group (p < 0.05) by the TUNEL method.

According to the results of our study, the very low dose magnetic field, which is considered to be used for therapeutic purposes recently, can cause both auditory function defects and histopathologic damage in cochlear cells.