If I use Presentation, how can I deliver calibrated auditory stimuli for evoked potentials?

We offer specialized insert earphones that deliver sound to the ears through small tubes so that the transducer can be kept at a distance from the recording electrodes.  These earphones have an optimally flat frequency response, which makes them “calibratable”.  Using a sound-level meter, it is possible to measure the sound pressure level produced by a given digital sound file.  Using a digital sound editor (see below for a recommendation), it is possible to adjust the amplitude of the sound to a desired level and save the file in its “calibrated” form for use in Presentation.  You can also dynamically adjust the "volume" at which sound files are played using Presentation's "attenuation" feature.  Visit the Downloads page  to find a Presentation scenario that will simplify the process of determining appropriate attenuation levels to calibrate your sound files.

How can I create sound files containing tones, clicks or noise for use in Presentation?

A wide variety of digital sound editing programs is available on the market today.  There are several inexpensive, yet highly functional options.  One program we recommend is Adobe Audition (formerly Cool Edit).  Audition can synthesize pure and complex tones, clicks and noise.  It can also perform complex operations like windowing and filtering.  Results are saved in .WAV files for use in Presentation.  A trial version of Audition is available from Adobe.

What is the recommended arrangement of computers, monitors, keyboards and mice inside and outside the subject chamber for use with your ERP stimulus delivery systems?

Click here to download a PDF document containing a diagram of the recommended locations and connections between computers inside and outside the subject chamber.