Abstract

Overview

Earphones, while commonly used globally and considered safe within sound dose limits, also generate a static magnetic field (SMF) due to their built-in permanent magnets. This study investigates the SMF emissions from earphones and their potential biological implications.

Findings

• Experimental mapping of static magnetic fields near 6 earphone models.
• Physical modelling enabled simulation and extrapolation of these fields.
• 3D simulations visualized field distribution within the ear.
• Field intensity varied, with notable measurements from about 20 mT at the earphone surface down to tens of μT in the inner ear.
• The study raises concerns about bioeffects in the SMF intensity range found, which have been reported both acutely and chronically.
• The combination of SMF with other frequency fields (RF/ELF) remains under-researched, suggesting a potential for unknown health risks.

Conclusion

The presence of SMF in earphones and their debated effects on health highlight the need for further research and possibly more cautious use of such devices. The study tentatively suggests opting for air-tube earphones as a more conservative approach.

Reference to existing guidelines by the International Commission on Non-Ionizing Radiation Protection, which set higher limits than what was measured in this study, adds context but also points to potential gaps in understanding the full spectrum of effects from lower-intensity exposures.