Subject: Re: acoustic foam and soundproofing From: Mike Ravicz <Mike_Ravicz(at)MEEI.HARVARD.EDU> Date: Wed, 19 Oct 2005 12:19:52 -0400Hi Virginie, > we would like to soundproof a small tactile stimulus delivery device. > it would be best if that material does not cause artefact in fMRI or > EEG/MEG environments. We have had good results with E.A.R. E-0-10-25 acoustic foam-barrier composite <http://www.earsc.com/HOME/products/BarriersandAbsorbers/ BarrierComposites/index.asp?SID=187>. We've tried it in an fMRI scanner - I don't think it caused any major artifacts; don't know about MEG. See an unpublished poster from Human Brain Mapping 1999 <http://epl.meei.harvard.edu/~mer/HBM99posterhandout.pdf> and a more recent paper: Ravicz et al., J. Acoust. Soc. Am. 109: 216–231 (2001). How big is your device? How much isolation do you need? Are you isolating your subjects from noise produced by the device, or the device from the scanner noise? You may also want to consider a rigid box, perhaps lined with absorbent foam. Materials like particle board are good for reducing sound transmission. - Mike