Audiologic Testing

Audiologic Testing

Module Summary

Audiologic testing has amazing breadth and depth. It covers everything from routine screening to testing a specific portion of the auditory pathway. The key is knowing when and why to utilize a specific test. In many cases, an in depth understanding of the tests will help with your understanding of the disease process.

Module Learning Objectives 
  1. Review the different audiologic tests and how they are performed.
  2. Distinguish how to appropriately choose an audiologic test in a specific circumstance. 
  3. Describe the results of audiologic testing and their implications. 

 

Anatomy

Learning Objectives 
  1. Review the anatomy of the external, middle, and inner ear and what type of hearing loss occurs when there is a problem/pathology at any of these sites.
  2. Discuss function of the utricle and saccule in activation of ocular vestibular evoked myogenic potential(oVEMPs) and cervical vestibular evoked myogenic potential(cVEMPs). 
  3. Describe the path of sound energy through the outer ear, middle ear, and inner ear to the central pathway:
  • Through external auditory canal, to tympanic membrane (TM), malleus, incus, stapes, oval window, cochlear hair cells, and the cochlear nerve
  • Central pathway mnemonic: ECOLI- Eighth nerve, Cochlear nucleus, Olivary complex, Lateral lemniscus, and Inferior colliculus

 

References 
  1. Lee, K.J.. K.J. Lee's Essential Otolaryngology, Tenth Edition. New York: McGraw-Hill Education; 2012. P.1-23
  2. Lee, K.J.. K.J. Lee's Essential Otolaryngology, Tenth Edition. New York: McGraw-Hill Education; 2012. P.89
  3. Lee, K.J.. K.J. Lee's Essential Otolaryngology, Tenth Edition. New York: McGraw-Hill Education; 2012. P.26-29
  4. Flint, Paul W, Bruce H. Haughey, Valerie J. Lund, John K. Niparko, K T. Robbins, J R. Thomas, and Marci M. Lesperance. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Elsevier/Saunders; 2015. P. 2051-2070.

Patient Evaluation

Learning Objectives 
  1. Review Tuning Fork Tests (256Hz, 512Hz, 1024Hz) and what they can tell about SNHL and CHL. 
  • Recognize that weber test will lateralize to the side with worse hearing in the setting of unilateral conductive hearing loss, and to the better ear in unilateral sensorineural hearing loss. 
  • Discuss that a Rinne test will reveal BC>AC 
    • If there is at least a 15dB air bone gap with the 256Hz fork
    • If there is at least a 25dB air bone gap with the 512Hz fork
    • If there is at least a 15dB air bone gap with the 1024Hz fork
  1. Describe pure tone audiometry. This includes decibel(dB), sound pressure level(SPL), hearing level(HL), sensation level(HL), air conduction, bone conduction, how the threshold is determined, interaural attenuation, crossover, masking, speech reception threshold, speech awareness/detection threshold, word recognition score, conductive hearing loss, and sensorineural hearing loss.
  2. Recognize tympanometry, the different types of tympanograms, and normal and abnormal volumes.
  • Type A- represents normal middle ear pressure and TM mobility. Peak around 0 daPa
  • Type B- represents very little or no TM mobility with a flat or very low and rounded peak. Type B with normal volume is consistent with middle ear effusion. Type B with large volume is consistent with TM perforation or pressure equalization tube
  • Type C- peak in the region of negative pressure >-150daPa and would be consistent with a retracted TM
  1. Review acoustic reflexing pathway, testing, and how to interpret the results.
  • Acoustic reflex-Sound is typically delivered at 70 to 100dB HL which causes bilateral stapedial reflex
  • Acoustic reflex will be absent with significant conductive hearing loss or if >65dB SNHL
  1. Discuss tone decay test and Acoustic Reflex Decay: the implications of abnormal test.
  • If abnormal, each suggests retrocochlear pathology
  1. Understand ABR (auditory brain stem response) and ASSR (auditory steady state response).
  • ABR- tests integrity of the auditory system from cochlear nerve to the brainstem. Waves 1-5 are: Eighth nerve, Cochlear nucleus, Olivary complex, Lateral lemniscus, and Inferior colliculus respectively (ECOLI)
  • ASSR- similar to ABR but able to better give estimation of the level of hearing
  1. Describe Otoacoustic Emissions (OAE): different ways to test and their implications (spontaneous OAE, transient OAE, and distortion product OAE).
  • Otoacoustic emissions measure cochlear hair cell function
  1. Explain evaluation of the pediatric patient including behavioral observation audiometry, visual reinforcement audiometry, and conditioned play audiometry and the ages at which each of these is appropriate.
  • Behavioral observation audiometry (birth-6months)- sounds is presented and patient is observed for bodily response such as eye or body movement
  • Visual reinforcement audiometry (6-36months)- present sound and when child looks toward the source of the sound visual reinforcement in provided
  • Conditioned play audiometry (3-5years)- play sounds and child is taught to do a repetitive play task when they hear the sound
  1. Review testing for pseudohypoacusis or nonorganic hearing loss, suggestive audiometric findings, and appropriate testing (Acoustic reflex, ABR, OAE, Stenger test).
  • Understand that acoustic reflex, ABR, and OAE do not rely on the patient’s response and can give information on how the auditory system is functioning.
  • Understand that Stenger test utilizes the fact that when a tone is presented at the same time to each ear, the tone will only be heard on the side which is presented with the louder tone.
  1. Explain when electrocochleography (ECOG), oVEMP, and cVEMP can help with diagnosis.
  • Understand for cVEMP a click or tone burst is presented which stimulates the saccule, inferior vestibular nerve and central connection leading to activation of the ipsilateral sternocleidomastoid muscle
  • Understand for oVEMP a click or tone burst is presented which stimulates the utricle, superior vestibular nerve and central connection leading to activation of the contralateral inferior rectus/oblique muscle
  1. Review what testing is done for a newborn hearing screening.
  • ABR and/or OAE
References 
  1. Lee, K.J.. K.J. Lee's Essential Otolaryngology, Tenth Edition. New York: McGraw-Hill Education; 2012. P.24-59
  2. Lin, Fred Y, and Zara M. Patel. M. ENT board prep: High yield review for the otolaryngology in-service and board exams. 1st ed. Springer Science+Business Media New York; 2014. P.164-167
  3. Flint, Paul W, Bruce H. Haughey, Valerie J. Lund, John K. Niparko, K T. Robbins, J R. Thomas, and Marci M. Lesperance. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Elsevier/Saunders; 2015. P. 2051-2070.
  4. Flint, Paul W, Bruce H. Haughey, Valerie J. Lund, John K. Niparko, K T. Robbins, J R. Thomas, and Marci M. Lesperance. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Elsevier/Saunders; 2015. P. 2071-2083.

Measurement of Functional Status

Learning Objectives 
  1. Discuss the implication that mild, moderate, severe, and profound hearing loss has on quality of life.
  2. Describe the different impacts hearing loss has in children, adults, and elderly.
  • Speech delay is a common problem with hearing loss in children
  • In the elderly, there is evidence of a link between hearing loss and dementia
  1. Explain how poor word recognition score impacts quality of life.
  2. Review PTA (pure tone average) and how it is calculated.
  • Understand that PTA is calculated by averaging hearing level at 500Hz, 1000Hz, and 2000Hz

 

References 
  1. Flint, Paul W, Bruce H. Haughey, Valerie J. Lund, John K. Niparko, K T. Robbins, J R. Thomas, and Marci M. Lesperance. Cummings Otolaryngology: Head & Neck Surgery. 6th ed. Elsevier/Saunders; 2015. P. 2051-2070.
  2. Punch JL, Hitt R, Smith SW: Hearing loss and quality of life. J Commun Disord. 2019; 78:33-45
  3. Anne S, Lieu JEC, Cohen MS: Speech and Language Consequences of Unilateral Hearing Loss: A Systematic Review. Otolaryngol Head Neck Surg. 2017; 157(4):572-579.
  4. Tomblin JB, Harrison M, Ambrose SE, Walker EA, Oleson JJ, Moeller MP: Language Outcomes in Young Children with Mild to Severe Hearing Loss. Ear Hear. 2015; 36 1:76S-91S
  5. Loughrey DG, Kelly ME, Kelley GA, Brennan S, Lawlor BA: Association of Age-Related Hearing Loss With Cognitive Function, Cognitive Impairment, and Dementia: A Systematic Review and Meta-analysis. JAMA Otolaryngol Head Neck Surg. 2018; 144(2):115-126 

Case Studies

  1. An 18 month old female presents to your clinic because the mother is concerned that she is having trouble hearing. You learn that she is the first child. It was a full-term pregnancy and normal delivery. The mother thinks that she initially failed her newborn hearing screening but passed before leaving the hospital. No history of tugging at the ears, but the patient often does have nasal congestion and rhinorrhea. What audiologic tests could you do to better understand how the child is hearing?
  2. A 33 year old male presents to you clinic with bilateral hearing loss and tinnitus. He was at work with the fire alarm went off and he reports that he has noticed both the hearing loss and tinnitus since. Now he is interested in workers compensation and disability. What audiologic tests could you order to discern the function of his auditory system and his current level of hearing?
References 
  1. Lee, K.J.. K.J. Lee's Essential Otolaryngology, Tenth Edition. New York: McGraw-Hill Education; 2012. P.24-59 
  2. Lin, Fred Y, and Zara M. Patel. M. ENT board prep: High yield review for the otolaryngology in-service and board exams. 1st ed. Springer Science+Business Media New York; 2014. P.164-167

Review

Review Questions 
  1. What are the tests are typically involved in newborn screening?
  2. What is the pathway of sound recorded during an ABR?
  3. What tests can be useful if there is concern for nonorganic hearing loss?
  4. Why is appropriate audiologic testing important specifically in both younger and older patients?
  5. What audiologic testing could help if you were concerned with retrocochlear pathology? SSCD? Ménière’s disease?