Welch Allyn REF 29400, Directions For Use Manual

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Welch Allyn OAE Hearing Screener Directions for Use 705353 Rev E
5
Abbreviations
ART LVL - artifact level; refers to the threshold at which samples of data
coming into the Welch Allyn OAE Hearing Screener for processing are
rejected before averaging in order to keep noise from averaging into the
response. Artifact level is reported in pressure units, milliPascals (mPa).
WA OAE Load Software - loads the firmware that resides on the memory
chip inside the Welch Allyn OAE Hearing Screener. This software also can
be used to update the Welch Allyn OAE Hearing Screener date, time and
default protocol.
COM - communications port on a computer; also known as serial port.
dB - decibel; a logarithmic measure of sound intensity.
DP Frequency - the frequency at which the distortion product (DP) emission
occurs.
DPOAE - distortion product otoacoustic emission; refers to the acoustic
energy generated by the outer hair cells of the cochlea in response to
stimulation with two pure tone stimuli.
DP
-
distortion product; used interchangeably with DPOAE. The DP that has
received the greatest interest and is most often measured clinically is the DP
that is calculated by the formula 2F1-F2.
DP-NF - the dB difference between the distortion product emission and the
noise floor amplitudes. To be sure that a response is present, the DP-NF
value must match or exceed a minimum. On the Welch Allyn OAE Hearing
Screener, this value is 6 dB or greater.
DX - a button on the front panel of the Welch Allyn OAE Hearing Screener
which is used to SELECT and implement functions described on the LCD.
F2 - the higher of the two stimulus frequencies used in a DPOAE test.
F1 - the lower of the two stimulus frequencies used in a DPOAE test.
F2/F1 ratio - the numeric relationship of the two stimulus frequencies to one
another. Most research has shown that an F2/F1 ratio of approximately 1.2
produces the most robust emissions.
Hz - Hertz; a unit of measurement of frequency; also known as cycles per
second.
LCD - liquid crystal display; refers to the message window on the upper
portion of the Welch Allyn OAE Hearing Screener front panel.
LED - light emitting diode; a light that illuminates to indicate a hardware
function. On the Welch Allyn OAE Hearing Screener, an illuminated green
LED at the bottom left of the front panel indicates that the AC adapter is
plugged in and AC power is flowing to the box.