FAQ (Frequently Asked Questions)

Q: Does the S14 come with a warranty?
A: The S14 earphone system comes with a one-year warranty.

Q: Is the S14 earphone system approved for use in a 3T scanner?
A: The S14 earphone system has been tested and found safe for fMRI use in 3T Scanners. Please see the Safety Statement.

Q: Is the S14 earphone system approved for use in a 7T scanner?
A: No. Thus far, the S14 system has been tested for safety only in 3T scanners.

Q: Where can I get additional foam tips for the S14 earphones? Can I order them from Sensimetrics?
A: No. Sensimetrics doesn't sell the Comply Canal Tips replacement foam tips. You can buy them from Westone or directly from Comply.

Q: Do you sell an fMRI-compatible active noise removal feature or attenuator with this device?
A: We do not sell any active noise reduction devices. We recommend hearing protector earmuffs on top of the S14 insert phones as an effective means of achieving added noise reduction (provided, of course, that they fit in your head coil). Search the web for ‘dielectric earmuffs’.

Q: Is there an example of the frequency response specs for the S14 earphone system?
A: Yes. Please see this example of an individual specification sheet provided with each S14 system.

Q: Is it necessary/recommended to use an amplifier? What sort of audio amplifier do I need?
A: You can generate weak signals without one, but an amplifier is needed to produce sound levels that are usually used in fMRI research. The requirements for the amplifier are very modest. The transformer/earphone combination will require no more than 3 watts per channel, which may be met by a large number of small audio amplifiers. Note that some amplifiers incorporate a loudness correction that effectively changes the frequency response along with overall gain as the volume is controlled. It is also recommended that you use a linear "analog" amplifier and avoid using a "digital" amplifier with the S14 system in order to avoid possible interference with the scanner. As an example, the Pyle Home PCA1 has been used successfully with the Model S14 earphone system.

Q: Do you have any official designation that the S14 earphones are MR safe?
A: The S14 is MR Compatible (according to ASTM labeling). The limits for safe use are stated in the product Safety Statement.

Q: How much attenuation of external sounds do the S14 insert earphones provide?
A: An S14 earphone inserted in a measurement device with no leaks achieves the same level of attenuation as a foam plug. Please see the Technical Note on Attenuation for more information.

Q: What type of transducer is used in the S14 earphones?
A: The earphones are piezoelectric. They contain a 12-mm disc of piezoelectric material to which a thin brass disc is bonded.  

Q: What conductor material is used in the leads in the earphone cable and in the 9-meter cable?
A: The conductors are all twisted-pair copper, which is non-magnetic.

Q: I'm having trouble reading .wav files in EQ Filtering. Is there a fix?
A: Yes. Some audio editing software is known to create .wav files that are incompatible with early versions of the EQ Filtering Software. If you are having trouble using .wav files in EQ Filtering, you are encouraged to download the "EQ Filtering WAV File DLL Update" from the download page. This DLL fixes a problem in EQ Filtering 2.0 where certain types of .wav files are read incorrectly. Another work around is to open and save the .wav files in another program prior to opening the files into EQ Filtering.

Q: The EQ Filtering software is crashing, or is not working correctly. Is there an update available?
A: Yes. Version 2.1 of EQ Filtering is available for download to all S14 users from our download page.

All users EQ Filtering version 2.0 are encouraged to update to version 2.1 of the EQ Filtering software. This update addresses the following issues:

1) On some systems, filters applied to wav files that were less than a certain length sometimes caused the program to crash. This error has been corrected.

2) Stereo input files were output as mono files if the Mono Input To selector specified Left Only or Right Only. Stereo input files are now always processed and saved as stereo output files.

Q: While installing EQ Filtering on Window 7, I get the error "Unhandled exception has occurred in this application." Does EQ Filtering work with 32bit and 64bit Windows 7?

A: All S14 users are encouraged to download and install version 2.1 of the EQ Filtering software from http://www.sens.com/downloads.

Q: What is the EQ filtering software exactly doing? Is it similar to an external/analog EQ system?
A: The EQ Filtering software uses digital filters custom-matched for your earphones to compensate for (remove) resonances in the frequency responses of the earphones. The compensation is applied to digital signals that are stored on your computer.