title: A measure of acoustic noise generated from transcranial magnetic stimulation coils.
abstract: The intensity of sound emanating from the discharge of magnetic coils used in repetitive transcranial magnetic stimulation (rTMS) can potentially cause acoustic trauma. Per Occupational Safety and Health Administration (OSHA) standards for safety of noise exposure, hearing protection is recommended beyond restricted levels of noise and time limits. We measured the sound pressure levels (SPLs) from four rTMS coils with the goal of assessing if the acoustic artifact levels are of sufficient amplitude to warrant protection from acoustic trauma per OSHA standards. We studied the SPLs at two frequencies (5 and 10 Hz), three machine outputs (MO) (60, 80 and 100%), and two distances from the coil (5 and 10 cm). We found that the SPLs were louder at closer proximity from the coil and directly dependent on the MO. We also found that in all studied conditions, SPLs were lower than the OSHA permissible thresholds for short (<15 min) acoustic exposure, but at extremes of use, may generate sufficient noise to warrant ear protection with prolonged (>8 h) exposure.
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Sameer C
authors.initials: SC
authors.lastname: Dhamne
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Raveena S
authors.initials: RS
authors.lastname: Kothare
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Camilla
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Graduate Institute of Neural Regenerative Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Tsung-Hsun
authors.initials: TH
authors.lastname: Hsieh
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Elana M
authors.initials: EM
authors.lastname: Anastasio
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Oberman
authors.affiliation: Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Institut Universitari de Neurorehabilitació Guttmann, Universidad Autónoma de Barcelona, Badalona, Spain.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual-Leone
authors.affiliation: Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA. Electronic address: alexander.rotenberg@childrens.harvard.edu.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rotenberg
mesh_terms: D000162:Acoustics; D004867:Equipment Design; D034381:Hearing Loss / Q000517:prevention & control; D006801:Humans; D008280:Magnetics; D009622:Noise; D016273:Occupational Exposure; D013016:Sound; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects*; D014481:United States; D014489:United States Occupational Safety and Health Administration
keywords: Acoustic noise; Sound pressure levels; Transcranial magnetic stimulation