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Effect of bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve

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Mandalà M, Colletti V, Sacchetto L, Manganotti P, Ramat S, Marcocci A, Colletti L. · 2013

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Mobile phone EMFs directly impaired human auditory nerve function in minutes, while Bluetooth headsets showed no effects.

Plain English Summary

Summary written for general audiences

Researchers directly exposed the auditory nerves of 12 patients to both mobile phone radiation (900 MHz) and Bluetooth headset radiation (2.4 GHz) during surgery. They found that mobile phone EMFs significantly impaired nerve function by reducing signal strength and delaying response times, while Bluetooth EMFs caused no measurable changes. This suggests Bluetooth headsets may be a safer alternative for protecting auditory nerve health during phone calls.

Why This Matters

This study provides rare direct evidence of EMF effects on human nervous system function, bypassing the usual limitations of studying EMFs through skin and tissue. The finding that 900 MHz mobile phone radiation measurably impairs auditory nerve function within just 5 minutes is significant, especially since this occurred at an SAR of 0.82 W/kg - well within current safety limits. What makes this research particularly valuable is the direct comparison showing Bluetooth technology at 2.4 GHz produced no detectable nerve effects. While the surgical setting means higher direct exposure than typical phone use, the results support what many EMF researchers have long suspected: that the specific frequencies and power levels of different wireless technologies matter enormously for biological effects. For anyone concerned about EMF exposure from phone calls, this study provides scientific backing for choosing Bluetooth or wired headsets over holding phones directly to your head.

Exposure Details

SAR
0.82 W/kg
Source/Device
900 MHz mobile phone and 2.4 GHz Bluetooth headset
Exposure Duration
continuous for 5 min

Exposure Context

This study used 0.82 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 0.82 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern rangeFCC limit is 2x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 900 MHz - 2.40 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 900 MHz - 2.40 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The possibility that long‐term mobile phone use increases the incidence of astrocytoma, glioma and acoustic neuroma has been investigated in several studies. Recently, our group showed that direct exposure (in a surgical setting) to cell phone electromagnetic fields (EMFs) induces deterioration of auditory evoked cochlear nerve compound action potential (CNAP) in humans. To verify whether the use of Bluetooth devices reduces these effects, we conducted the present study with the same experimental protocol.

Twelve patients underwent retrosigmoid vestibular neurectomy to treat definite unilateral Ménière's ...

We found no short‐term effects of Bluetooth EMFs on the auditory nervous structures, whereas direct ...

The outcomes of the present study show that, contrary to the finding that the latency and amplitude of CNAPs are very sensitive to EMFs produced by the tested mobile phone, the EMFs produced by a common Bluetooth device do not induce any significant change in cochlear nerve activity. The conditions of exposure, therefore, differ from those of everyday life, in which various biological tissues may reduce the EMF affecting the cochlear nerve. Nevertheless, these novel findings may have important safety implications.

Cite This Study
Mandalà M, Colletti V, Sacchetto L, Manganotti P, Ramat S, Marcocci A, Colletti L. (2013). Effect of bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve Laryngoscope. 2013 Apr 25. doi: 10.1002/lary.24103.
Show BibTeX
@article{m_2013_effect_of_bluetooth_headset_136,
  author = {Mandalà M and Colletti V and Sacchetto L and Manganotti P and Ramat S and Marcocci A and Colletti L.},
  title = {Effect of bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve},
  year = {2013},
  doi = {10.1002/lary.24103},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lary.24103},
}
DOI: 10.1002/lary.24103

Cited By (13 papers)

Quick Questions About This Study

Yes, cell phone radiation can impair auditory nerve function. A 2013 study found that 900 MHz mobile phone EMFs significantly reduced nerve signal strength and delayed response times when directly exposed to patients' auditory nerves during surgery.
Yes, Bluetooth headsets appear safer for auditory nerve health than cell phones. Research shows Bluetooth radiation (2.4 GHz) caused no measurable changes to nerve function, while mobile phone EMFs significantly impaired auditory nerve activity.
No, Bluetooth radiation does not appear to affect hearing based on current research. A 2013 study directly exposed patients' auditory nerves to Bluetooth EMFs during surgery and found no significant changes in nerve activity.
Phone radiation can reduce auditory nerve signal strength and slow response times. Direct exposure to 900 MHz mobile phone EMFs significantly impaired nerve function in surgical patients, suggesting potential risks to hearing health.
Cell phone EMF exposure reduces nerve signal amplitude and increases response latency. Research found that 900 MHz mobile phone radiation directly applied to auditory nerves decreased signal strength and delayed nerve responses in all tested patients.