Installation & Operation Manual

Wilat_Op_Man_23Oct08.doc CONFIDENTIAL
Aearo Technologies Page 11 of 21 18/07/2007
2.4 Installing the WRU
Note: Italicized numbers enclosed in parenthesis refer to the respective component diagrams on
Page 7 of this manual.
1. Following the color coding specified above, connect the three dual-pin transducer cords to
the WRU audio outputs (19, 20, & 21).
Note: The dual-pin audio cords must be connected both to the WRU and to each (Left/Blue,
Right/Red, and BC/Green) transducer as described below. The connectors and receptacles
are polarized, with one pin/hole larger than the other. The correct pin orientation can be
ascertained visually. Be careful to connect the audio cords with the correct orientation.
Reverse the pin orientation if resistance to the connection initially occurs. Forcing the
plugs into the WRU or the transducer receptacles incorrectly could permanently damage
the connector or the receptacle.
2. Connect the insert phone transducers and user provided bone conductor to the audio cords.
3. If used, connect the URB cord to the URB jack (25)
4. Turn the ON/OFF switch (24) to ON and observe the LEDs:
4.1. If the battery charge is good (more than one hour of WRU operation available), both the
YELLOW (22) and ORANGE (23) LEDs will flash four times, and then only the YELLOW
LED (22) will glow.
4.2. If the battery charge is low (less than one hour of operation available), the YELLOW and
ORANGE LEDs will not flash, but the YELLOW LED will glow.
5. Check the "No Link" LED (10) on the WBU; it should cease flashing and turn off quickly after
the WRU is turned ON, as the wireless link is established between the base and remote
units.
3. Calibration
3.1 Pure Tone Calibration
As is the case with any change of audiometric transducer, and periodically thereafter, the
audiometer to which the E-A-RTONE
®
WiLAT system is connected must be calibrated specifically
for that system. Before calibration is accomplished, the WiLAT must be set up, installed, and
functioning properly, as described above in section 2. Verify that the WRU is fully charged and
that the No Link LED on the WBU (10) is not flashing. The system can then be calibrated
following the procedure outlined below and detailed in ANSI S3.6-2004, using the values
referenced in this section and in ANSI S3.6-2004 for the 2cc acoustic coupler type used. The
current ANSI “Specification for Audiometers” standard provides reference thresholds for the
HA-1, HA-2 (DB 0138) and Ear Simulator 2cc couplers. The Bruel & Kjaer 2cc DB-0138 (HA-2)
coupler will simplify the calibration procedure, and is recommended. Reference thresholds for the
DB-0138, IEC 711, and HA-1 couplers are also provided below. Should calibration be performed
for an audiometer currently calibrated towards ISO-389, the reference thresholds in a 2cc DB-
0138 coupler should be used. In order to calibrate the audiometer for direct readings of the
hearing thresholds in dBHL using the reference thresholds, the following basic procedure is
recommended;