Using Etymotic Research equipment for Physiology

[Didier A Depireux <didier@xxxxxxxxxxx>]

        We do physiological recordings in the Auditory Cortex and IC of
ferrets. Our sound delivery set-up consists in a conical speculum, sewed onto
the meatus of the ear (after cutting the ear off), with a 19mm Sony earphone
attached to it, and a small hole in the side of the speculum to insert a 1/8"
B&K 4170 microphone.

        The 1/8" B&K just died and B&K is asking 4500$ to replace it. So I
was thinking that instead, we might get an Etymotic Research system, using
an ER-2 sound delivery system, with an ER-7C microphone.  Both the ER-2 and
the 7C use silicon tubing, between the loudspeaker or the microphone and
the ear, with outer diameters of 3mm and .95 mm respectively.

        I thought we could put the tubes together, make a custom earplug
ourselves, and use the ER-2 and the 7C for sound delivery and monitoring.
We typically only go up to 16kHz. I was wondering whether anyone uses such
a set-up for their recordings, and if so whether they would have
warnings/advice they could give us. Anyone who would have a useful comment
to make would be welcome too, of course.

                                                Thanks in advance,

                                                        Didier

--
Didier A Depireux                              didier@isr.umd.edu
Neural Systems Lab                 http://www.isr.umd.edu/~didier
Institute for Systems Research          Phone: 301-405-6557 (off)
University of Maryland                                -6596 (lab)
College Park MD 20742 USA                     Fax: 1-301-314-9920