The Test Equipment
The care used in setting up your test area must also be taken when selecting and setting up
your test equipment. TDT's ABR system is part of a modular experiment platform. Each module
in the system is designed for exceptional signal
fi
delity, precise timing, low noise, and ease of
use.
The sub-sections below discuss the role each part of the system plays in running an ABR
experiment and provides information on making the necessary connections.
Needle Electrodes
In a research environment with non-human subjects, ABRs are typically recorded using sub-
dermal needle electrodes. There are a wide variety of suitable electrodes available. When
working with a TDT System, you will need electrodes with 1.5 mm female safety connectors
(also known as Touch-Proof connectors) to be used with the Medusa4Z. TDT recommends
disposable, 12 mm long, 27 gauge needle electrodes with 18" color coded lead wires. In
general, selecting the shortest available lead wires helps keep the noise
fl
oor as low as
possible. Some test protocols using small subjects, such as mice, may
fi
nd that 29 gauge
electrodes are more workable. Keep in mind that smaller gauge electrodes are lighter, but are
also less robust and more likely to dull quickly.
The Test Equipment | 14
