If independent monaural stimulation is not necessary, like for some language paradigms, one could consider a flat panel speaker in the msr. Because the use a piezo electric membrane no current flows. Now artifact there. In addition, the sound quality is definitely much higher than those tiny tubes. They are manufactured by Panphonics in Finland and the one we have costs approx. $850 including the amplifier. Michael Sent from my iPad On Feb 17, 2012, at 2:00 AM, "VAN WASSENHOVE Virginie" <[log in to unmask]<mailto:[log in to unmask]>> wrote: Dear all, Antoine, Etienne: this is indeed the default setup with neuromag which is clearly far from optimal – the transducers are actually placed further away than the recommended spots. We are double-checking proper removal of those artifacts with sss for now (Antoine, I trust you have already been through that a lot so it sounds like good option for now) and optimal configurations in the short-term. I am of course concerned by other points that have been raised, namely the sound quality that will be impacted with longer tubing etc. Some responses provided offline are also quite telling and particularly relevant for speech studies and refined acoustics which we also plan to run here… In sum, many thanks for the different recommendations from you all as we will likely look into a more sophisticated audio system in the very near future. I might get back in touch with some of you for a better sense of the specifications you have opted for. See you all in Biomag! Best wishes, Virginie Virginie van Wassenhove . CEA.DSV.I2BM.NeuroSpin - INSERM Cognitive NeuroImaging Unit Bât 145 Point Courrier 156 . Gif sur Yvette F-91191 . France Ph: + 33 (0)1.69.08.1667 . [log in to unmask]<mailto:[log in to unmask]> . [log in to unmask]<mailto:[log in to unmask]> http://sites.google.com/site/virginievanwassenhove https://sites.google.com/site/ceaunicogmeg From: Discussion list for international MEG community [mailto:[log in to unmask]] On Behalf Of LABYT Etienne 226379 Sent: Friday, February 17, 2012 9:49 AM To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: [megcommunity] etymotic earphones and magnetometers Dear Virginie, Yes, indeed, this problem with Etymotic system is known and it is recommended to maintain with tape the transducers on the small table in forn of the subject or better,, on the back of the MEG armchair (there are scratch to do this). Bye Etienne Etienne Labyt, PhD Responsable Imagerie Responsable plateforme MEG/EEG CEA-Leti, CLINATEC MINATEC Campus, 17 rue des Martyrs 38054 GRENOBLE Cedex 9 [log in to unmask]<mailto:[log in to unmask]> Tél. : + 33 (0)4 38 78 06 87 – Fax et/ou mobile : + 33 (0)4 38 78 53 55 www.leti.fr<http://www.leti.fr/> <image001.jpg> <image002.jpg> ________________________________ De : Discussion list for international MEG community [mailto:[log in to unmask]] De la part de Antoine Ducorps Envoyé : jeudi 16 février 2012 15:57 À : [log in to unmask]<mailto:[log in to unmask]> Objet : Re: [megcommunity] etymotic earphones and magnetometers Dear Virginie, We also experienced this problem with our Elekta Triux, this was already the case with our previous CTF system. As a solution, we keep the transducers as far as possible from the sensors, and for that longer audio tubes help (we had 1 meter tubes with CTF). Then the remaining artefact should be well removed by SSS, as clearly originating from outside the sensor sphere. Hoping this comment helps, Very best regards, Antoine. --------------------------------------------------------------- Antoine Ducorps CENIR - Centre de Magnétoencéphalographie Tél (33) 1 42 16 11 62 (bureau) (33) 1 42 16 14 10 (MEG) http://www.cenir.org/ http://cogimage.dsi.cnrs.fr/ --------------------------------------------------------------- Adresse postale: CRICM - UMR 7225 / UMR-S 975 CENIR Plate-forme MEG-EEG Hôpital de la Pitié Salpêtrière 47, Bd de L'Hôpital 75651 Paris Cedex 13 - France --------------------------------------------------------------- Le 16 févr. 2012 à 15:31, VAN WASSENHOVE Virginie a écrit : Dear all, we noticed that some magnetometers could be sensitive to sounds sent through the Etymotic system - empty room/remotely from the system. This appears to be directly due to the transducer parts. Has any of you experienced such (very problematic) issue? Has attempts to better isolate this system been helpful? Thanks in advance for any suggestion. Cheers, Virginie Virginie van Wassenhove . CEA.DSV.I2BM.NeuroSpin - INSERM Cognitive NeuroImaging Unit Bât 145 Point Courrier 156 . Gif sur Yvette F-91191 . France Ph: + 33 (0)1.69.08.1667 . [log in to unmask]<mailto:[log in to unmask]> . [log in to unmask]<mailto:[log in to unmask]> http://sites.google.com/site/virginievanwassenhove https://sites.google.com/site/ceaunicogmeg