Download Real Ear Unaided Response REUR

Probe Tube Microphone
Measurements
(Basics and Definitions)
Greg Nassar
MCHAS Team
University of Manchester
Prescriptive
Targets
Probe Tube
Microphone
Measures
Best Fit within
Fitting Software
2cc Coupler
Individual ear
canal size
Individual
ear canal
acoustics
Kemar
Targets
Based on
Pure Tones
Different
Input levels
Targets
based on
Speech
Probe tube
Measurement microphone
Reference microphone
Supporting wire
Umbo
Light Reflex
Probe Tube
ULL
HTL
Real Ear Unaided Response
Clinical measurement of Real Ear
Unaided Response (REUR)
REUR
The SPL as a function of
frequency in the unoccluded
ear canal. Is expressed as
either SPL or gain in dB
relative to the stimulus level.
Real Ear Unaided Response
REUR
The SPL as a function of
frequency in the unoccluded
ear canal. Is expressed as
either SPL or gain in dB
relative to the stimulus level.
Real Ear Unaided Response
Real Ear Aided Response
REUR
The SPL as a function of
frequency in the unoccluded
ear canal. Is expressed as
either SPL or gain in dB
relative to the stimulus level.
REAR
The SPL as a function of
frequency in the ear canal with
the hearing aid in place and
turned on.
Also known as in situ response
and is normally displayed as
dB SPL
Real Ear Unaided Response
Real Ear Aided Response
REUR
The SPL as a function of
frequency in the unoccluded
ear canal. Is expressed as
either SPL or gain in dB
relative to the stimulus level.
REAR
The SPL as a function of
frequency in the ear canal with
the hearing aid in place and
turned on.
Also known as in situ response
and is normally displayed as
dB SPL
Real Ear Unaided Response
Real Ear Aided Response
REUR
The SPL as a function of
frequency in the unoccluded
ear canal. Is expressed as
either SPL or gain in dB
relative to the stimulus level.
REAR
The SPL as a function of
frequency in the ear canal with
the hearing aid in place and
turned on.
Also known as in situ response
and is normally displayed as
dB SPL
Real Ear Unaided Response
Clinical measurement of real ear
aided response (REAR)
Real Ear Unaided Response
Real Ear Unaided Response
Open Ear Gain
Insertion Gain
Open Ear Gain
Insertion Gain
Target
Insertion Gain
Open Ear Gain
Insertion Gain
Target
Insertion Gain
Open Ear Gain
In adults the REIR is the
measure of choice in verifying
the electroacoustic
characteristics of the chosen
hearing aid meet the prescribed
gain and desired frequency
response.
The difference in dB as a function of
frequency between the REUR and the
REAR (REIR=REAR-REUR).
The real ear insertion gain is the value in
dB of the REIR at a specific frequency
PTM’s on Children
REAR should be used rather than
REIR. The REAR will prescribe the
same gain at the eardrum for a given
hearing loss, regardless of ear canal
size and shape.
This ensures target speech levels at
the child’s eardrum will meet the
requirements of the hearing impaired
ear despite changes in resonant
frequencies of the child’s ear canal
over the first few years of life.
RESR
Is the SPL as a function of
frequency in the ear canal with
the hearing aid in place and
turned on. The measurement
is obtained with the stimulus
level sufficiently intense as to
operate the hearing aid at its’
maximum output level.
ULL
RECD
HTL
Is the difference in dB as a
function of frequency between
the outputs of a hearing aid
measured in the real ear
versus a 2cc coupler.
Using these measurements
the real ear performance of
the hearing aid can be
predicted.
Key Points to Take Away!
REIG target based upon the average adult ear canal resonance
Not appropriate to ear canal with different
acoustic properties to average adult ear
REAR target based upon the desired SPL at the eardrum
This is always the same for a given hearing
threshold (dB SPL) regardless of the size of
the ear canal…..
However the output of the hearing aid still
needs to be corrected for differing ear canal
sizes