Distortion product otoacoustic emissions
Distortion product otoacoustic emissions (DPOAEs) are acoustic signals that can be
detected in the ear canal of a person with normal outer hair cell function, subsequent to
stimulation of the auditory system with a pair of pure tones at frequencies f1 and f2. The
resulting emission of interest is the distortion product tone at the frequency 2f1-f2.
The screener generates a series of test tones, directs them into the ear canal, and then
measures the level of the DPOAE tone generated by the cochlea. By using different test
frequencies, the screener provides an estimate of outer hair cell function over a wide
range of frequencies.
Transient evoked otoacoustic emissions
Transient Evoked Otoacoustic Emissions (TEOAEs) are acoustic signals that can be
detected in the ear canal of a person with normal outer hair cell function, subsequent to
stimulation of the auditory system with a series of wideband clicks.
The screener generates a series of clicks, directs them into the ear canal, and then
analyzes the spectrum of the returning signal, separating the noise and emission. By
using band pass filters, the screener provides an estimate of outer hair cell function over
a wide range of frequencies.
Frequency Range tested
The frequency range tested is approximately 2 kHz to 5 kHz for DPOAEs. The frequency
range for TEOAEs is 1.5 kHz to 4 kHz.
Results storage and reporting
When the screener is set in its default settings, the instrument stores the results from
one patient (left and right ears) in its non-volatile memory for subsequent printing. The
screener is capable of storing up to 250 test results.
The results are displayed on the LCD on the front of the device and are stored in the
device’s internal memory. After testing is complete, results can be printed using the
printer or exported to a computer.
Sensitivity and specificity
Sensitivity and specificity in the screener are based on the test characteristics that you
define and may vary, depending on environmental and operating conditions. The
presence of otoacoustic emissions suggests normal outer hair cell function, which in
turn correlates to normal hearing. However, a passing result using the screener is not an
indication that the full auditory system is normal. Thus, a PASS result should not be
allowed to override other indications that hearing is not normal. A full audiologic
evaluation should be administered if concerns about hearing sensitivity persist. A REFER
test result should not be assumed to be an indicator of a lack of auditory function;
however, it should be followed with full audiologic diagnostic testing.
Directions for use
Introduction 9
Summary of Contents for 35900-NP-TE
Page 1: ...Welch Allyn OAE Hearing Screener Directions for use ...
Page 10: ...6 About warnings and cautions Welch Allyn OAE Hearing Screener ...
Page 14: ...10 Introduction Welch Allyn OAE Hearing Screener ...
Page 22: ...18 Setup Welch Allyn OAE Hearing Screener ...
Page 40: ...36 Manage results Welch Allyn OAE Hearing Screener ...
Page 46: ...42 Maintenance Welch Allyn OAE Hearing Screener ...
Page 56: ...52 Standards and compliance Welch Allyn OAE Hearing Screener ...
Page 58: ...54 Warranty Welch Allyn OAE Hearing Screener ...
Page 62: ...Appendix B Flowchart Measurement 58 Appendices Welch Allyn OAE Hearing Screener ...
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