A study from Xi’an Jiaotong University in China found that the acoustic noise produced by imaging machines can cause temporary hearing impairment even when patients are using earplugs and motion-refraining sponge mats. Not wearing adequate hearing protection can not only result in temporarily damaging the hearing system, but it can provoke other symptoms such as headaches and dizziness.
Researchers gathered 26 healthy volunteers between the ages of 18 and 30 years old to submit to 51-minute long 3T MR neuroimaging tests that featured “T1-weighted three-dimensional gradient-echo sequence, T2-weighted fast spin-echo sequence, diffusion-tensor imaging, diffusion-kurtosis imaging, T2*-weighted three-dimensional multiecho gradient-echo sequence, and blood oxygen level–dependent imaging.” The tests were conducted at noise pressure levels between 103.5 and 11.3 decibels. The scientists then measured their hearing thresholds at intervals of 24 hours, 20 minutes, and 25 days post-procedure. They found that auditory brain stem response threshold shifted 5 decibels plus or minus 8.1 right after the MRI exam. However, a 25-day follow up demonstrated no auditory changes.
“This finding further supports the importance of appropriate hearing protection in clinical practice,” wrote the authors. “Furthermore, developing protective apparatus with higher level of noise attenuation is desired for reducing the potential risk of hearing loss.”