Acoustic Reflexes Tutorial

1) What muscles contract during the acoustic reflex?

2) When do normal hearing people have an acoustic reflex?

3)  What is recruitment?

4)  Will all people with a cochlear loss have recruitment?

5)  Will people with a retrocochlear or conductive loss have recruitment?

6)  Will people with cochlear losses have acoustic reflexes? At what intensity?

7)  What are the parts of the acoustic reflex measurement system?

8)  What does it mean when you say an acoustic reflex can be elicited
monaurally, but measured either ipsilaterally or contralaterally?

9)    What is a "right contralateral reflex"?

10)  If a person has a 50 dB HL loss at all frequencies, and the loss is cochlear in origin,
and that person then has an acoustic reflex at, let's say 1000 Hz at 95 dB HL, what is the
sensation level of that reflex?  How do you calculate reflex sensation level?

11)  A person's hearing threshold is 30 dB HL, and the ipsilateral reflex occurs at
85 dB HL at the same frequency and ear. What is the sensation level of the reflex?

12)  Normal hearers have acoustic reflexes at what intensity hearing level, and
what intensity sensation level?

13)  Why does a reduced sensation level reflex indicate cochlear pathology?

14)  Does a person with a conductive loss typically have an ipsilateral acoustic
reflex in the ear with the conductive problem?

15)  What if the person has a slight conductive loss in the right ear, but normal middle
ear function in the left ear.  You are measuring a right contralateral reflex.  Do you think
you will see a reflex?  At what levels?

16)  What reflex threshold findings are typical of retrocochlear involvement?  Why?

17)  What is tone decay?  What is reflex decay?

18) What pathologies have abnormal reflex decay?

19)  What does a reflex decay trace look like? What is the criterion for abnormal
decay, since normal hearers can have some decay.

20)  To recap, what are the reflex findings anticipated with a cochlear loss?
With a conductive loss?  With a retrocochlear loss?

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Content Copyright (c) 2002 Nova Southeastern University
Teri Hamill, Ph.D., FAAA, CCC-A