Questions about the BOLDfonic?
BOLDfonic delivers high-fidelity acoustic stimuli for fMRI while also attenuating scanner noise. Our electro-dynamic driver technology uses the magnetic field of the MRI scanner to drive the headphone membranes. This results in powerful speakers with an excellent frequency response across a wide dynamic range. A novel USB sound processor with automated synchronous triggering capabilities and a fully–loaded amplifier system provide all the controls you need for rigorous multimodal EEG/fMRI studies.
Guide price includes a desktop microphone and speakers, plus one pair of headphones and the earbuds. Many options are available, so please contact us for more details.
Guide Price: £6750
The solution when space within the coil is limited
Some headcoils allow insufficient space for circumaural headphones. This simple and effective solution places the headphone driver unit just outside the coil, and delivers the audio to the ear via a short airtube and passive earbud.
Electro-dynamic earphone drivers
The drivers use the same proven electrodynamic system technology as other MR-safe headphones. They're safe to place within the bore or headcoil, so you can position them wherever is convenient. Ideally they should be reasonably close to to the ear, in order to keep the airtube length short. The drivers are connected to the control box either via your filter panel (using BNCs) or via your waveguide (using a waveguide spider).
The airtube can be detached from the driver, so that the ear plugs can be inserted conveniently whilst outside the magnet. Various lengths of airtube are available, depending on where you choose to place to drivers.
The sound pressure level at the driver is over 130dB, and decreases as the airtube length increases.
The frequency response is also a function of the tube length, for example 40Hz-12kHz for a 30cm tube or 40Hz-5kHz for an 80cm tube.
Various types of earplug are available.
Passive ear defenders
Passive ear defenders can be placed over the ears to reduce scanner noise. The ear defenders squash down well, taking up relatively little space.