Interacoustics OtoRead Instructions For Use Manual page 8

OtoRead™ Instructions for Use - US
How does the OtoRead
The OtoRead TM instrument generates a series of clicks, directs them into the ear canal, and then analyzes
the spectrum of the returning signal, separating the noise from the emission. By using band pass filters, the
TM
OtoRead device provides an assessment of outer hair cell function over a wide range of frequencies.
What frequency range of hearing is assessed?
DPOAEs: Approximately 1 kHz to 12 kHz (depending on the frequency range selected). Since the health of
the hair cells in the region of the f2 test frequency is assessed, and a) the 2f1-f2 emission frequency is at
about six-tenths of the f2 frequency, b) emissions tend to be weak below 600 Hz or so, and c) the ambient
noise tends to be highest at low frequencies, the lowest f2 test frequency that can be routinely measured is
about 1 kHz.
TEOAEs: Roughly 500 Hz to 4 kHz. TEOAEs can be reliably recorded at lower frequencies than DPOAEs,
but cannot be measured reliably above 4 kHz.
1.4 Contraindications
Contraindications to testing include recent stapedectomy or middle ear surgery, a discharging ear, acute
external auditory canal trauma, discomfort (e.g, severe otitis externa) or occlusion of the external auditory
canal. Testing should not be performed on patients with such symptoms without a medical doctor's approval.
For US only: Federal law restricts the sale, distribution, or use of this device to, by, or on the order of a
licensed medical practitioner.
1.5 Product description
TM
The OtoRead is a hand-held device designed to provide an objective measure of outer hair cell function
through the measurement of cochlear emissions. It consists of the handheld unit, printer, single-use eartips
and other accessories.
Factory-defined protocols allow for simple screening measurements (Screener and Screener
using customizable protocols it can also assist in diagnostic evaluations (Standard and Clinical Version).
The purpose of the OtoRead
Product Otoacoustic Emissions (DPOAEs) or Transient Evoked Otoacoustic Emissions (TEOAEs) at several
frequencies. The digital signal processor in the instrument generates two pure tones (f1 and f2) for DPOAEs
or a series of wideband clicks for TEOAEs through a digital-to-analog converter. These tones or clicks are
presented to the ear via speaker tubes located in the probe. A microphone in the probe measures the sound
in the ear canal and transmits the signal to the analog-to-digital converter. The digital signal processor then
uses Fast-Fourier Transforms (FFTs) to filter the signal into narrow frequency bands, and detects any
emissions present. The level of these emissions can be compared with the level of the noise. The SPL and
frequencies of the test tones and the averaging time used to process the signals can be determined by the
tester through adjustable settings maintained in static memory within the OtoRead
The OtoRead TM instrument may be used as a screening tool or in conjunction with conventional tests as part
of a full audiological evaluation.
TM
device measure TEOAEs?
TM
test system is to provide rapid measurement and documentation of Distortion
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Version) and by
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instrument.