Evoked Auditory Responses in Normals across Stimulus Level

This database, created and contributed by Michael J. Epstein and Ikaro Silva, was generated as part of a study examining evoked potentials and loudness growth. The database consists of two sets of physiological signals: auditory brainstem response (ABR) and otoacoustic emissions (OAE) and two sets of psychoacoustical estimates of loudness as a function of peak sound pressure level (peSPL). The ABRs were recorded simultaneously with the OAEs in a sound-attenuating, electrically shielded booth. Listeners had three electrodes affixed: the non-inverting electrode was positioned on the forehead, the inverting electrode was positioned on the ipsilateral mastoid (behind the ear), and the ground electrode positioned on the contralateral mastoid. (These locations were scrubbed with alcohol prior to the electrode placement.) The electrode signal was then sent to a GRASS QP511 Quad AC Amplifier, where it was band-pass filtered from 30-3000 Hz, amplified by a factor of 50000, sent to a 32-bit Lynx Two Soundcard (outside the booth), and sampled at 48 kHz. The effective resolution of the recording was 24-bits. Stimuli were presented at a presentation rate of about 24 Hz (2002 samples/trial).