Interacoustics Affinity2.0 Quick Manuals page 31

Quick Guide -
The purpose of this document is to provide a Quick Guide for instructions on how to administer the TEN test
with the AC440 Audiometry module in the Equinox
white paper that was written for Interacoustics by Brian C.J. Moore (2009)
What is the TEN test?
The TEN(HL) test was developed to provide clinicians with a quick and easy way to identify cochlear dead
regions. The test consists of measuring pure tone thresholds in a special masking noise, called the TEN
(Threshold Equalizing Noise).
What is a dead region?
A dead cochlear region is defined as a region of the cochlea where there are no functioning inner hair cells
and/or neurons. (Moore, 2001). When a pure-tone signal "falls" into a dead region, it can be heard by
neighboring hair cells, if the intensity of the signal is loud enough. This is because the pure tone produces
sufficient basilar-membrane vibrations in neighboring areas of the cochlea, where there are surviving IHCs and
neurons. This phenomenon is defined as "Off Frequency Listening". Clinically, this will present as a threshold
on the traditional pure tone audiogram, but it may not be the real threshold. It is not possible to use traditional
pure tone audiometry to determine if there is a dead region present; the TEN test was developed for this very
purpose.
When to do the TEN test?
Characteristics that could indicate the presence of a dead region (from Moore, 2009):

Severe to profound hearing loss

Absolute threshold is at a specific (suspected) frequency is 70 dB HL or greater

Steeply sloping hearing loss

Complaints of distortion

Extremely poor speech discrimination
Criteria for diagnosing a dead region (Moore et al) :
A dead region at a particular frequency is indicated when:
A masked threshold is at least 10 dB or more above the level of the TEN
Masked threshold is at least 10 dB above the non-masked threshold
Item No. 8105085 12/2013
TEN(HL) test in AC440
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, Affinity and Callisto™. This Quick Guide is based on a
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