All stimuli were presented binaurally using MR confon headphones (MR Confon GmbH, Magdeburg, Germany) and responses recorded with an MR compatible button box (Current Designs Inc, Philadelphia PA).
Acoustic stimuli were delivered by a magnetostatic headphone (MR-Confon, Magdeburg, Germany).
Stimuli were produced using COGENT 2000 (http://www.vislab.ucl.ac.uk/Cogent/) implemented in MATLAB (Mathworks Inc., MA) on a 2.8 GHz XEON DELL personal computer (Round Rock, TX) and were transmitted to the subjects using MR CONTROL amplifier and headphones (MR Confon, Germany).
Thirty stimuli were presented across 2 scanning runs via electrostatic headphones (MR confon GmbH, Magdeburg, Germany).
The stimuli were presented binaurally at a level of 75 dB SPL through MR-compatible high-fidelity headphones (MR Confon).
Stimuli were presented over MRI compatible headphones (MR Confon: http://www.mr-confon.de) at a comfortable listening level (estimated ∼70 dB).
Snugly fitting headphones (MR Confon, Magdeburg, Germany) dampened background scanner noise and enabled auditory stimulus presentation and communication with experimenters while in the scanner.
During these runs, sound was presented by means of MR-compatible electrodynamic headphones (MR Confon GmbH, Magdeburg, Germany) (Baumgart et al. 1998) that were connected to a standard PC with soundcard.
Additional passive measures, including electrodynamic headphones (MR Confon, Germany) and a removable sound-insulating foam insert (Ultra Barrier HD Composite, UltraBarrier USA) that conformed to the inside of the scanner bore, provided further acoustic noise attenuation.
The stimulus was presented to both ears using fMRI-compatible electrodynamic headphones (MR-Confon, Germany), specifically designed to reduce scanner noise, which were needed as the scanner noise is not equal across auditory frequencies [54] and may add biases in cochleotopic mapping.
Headphones (MR-Confon) dampened the scanner noise and were used for sound presentation.
