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Official Description

Acoustic immittance testing, includes tympanometry (impedance testing), acoustic reflex threshold testing, and acoustic reflex decay testing

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Acoustic immittance testing is a comprehensive evaluation process designed to assess the functionality of the middle ear, as well as to investigate potential disorders related to cranial nerve (CN) VIII, which is responsible for hearing and balance. This testing encompasses a series of specific procedures, including tympanometry, acoustic reflex threshold testing, and acoustic reflex decay testing. Each of these components plays a crucial role in diagnosing various conditions affecting the ear. Tympanometry, for instance, is a pivotal test that measures the compliance or flexibility of the tympanic membrane (eardrum). This measurement is essential for identifying issues such as fluid accumulation in the middle ear, negative pressure within the ear, perforations in the tympanic membrane, disruptions in the ossicular chain, and conditions like otosclerosis. During tympanometry, a device is inserted into the ear canal, and air pressure is varied to observe the eardrum's movement, which is graphically represented as a tympanogram. Acoustic reflex threshold testing evaluates the response of the stapedius muscle and tensor tympani to loud sounds, determining the softest sound that can trigger a reflex contraction of the stapedius muscle. This testing is crucial for understanding the middle ear's response to sound and can indicate potential dysfunction. Lastly, the acoustic reflex decay test assesses the integrity of CN VIII by measuring the response of the stapedius muscle to a sustained sound stimulus. A significant decrease in the muscle's response may suggest the presence of a retrocochlear lesion. Overall, acoustic immittance testing provides valuable insights into ear health and auditory function, enabling healthcare professionals to make informed decisions regarding diagnosis and treatment.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

Acoustic immittance testing is indicated for a variety of clinical scenarios where assessment of middle ear function and auditory pathways is necessary. The following conditions may warrant this testing:

  • Middle Ear Dysfunction Evaluation of conditions such as otitis media, eustachian tube dysfunction, and other abnormalities affecting the middle ear.
  • Cranial Nerve VIII Disorders Assessment of potential issues related to the vestibulocochlear nerve, which may impact hearing and balance.
  • Hearing Loss Investigation of the underlying causes of hearing impairment, particularly when conductive or sensorineural hearing loss is suspected.
  • Pre- and Post-Surgical Assessment Monitoring middle ear function before and after surgical interventions, such as tympanoplasty or stapedectomy.

2. Procedure

The procedure for acoustic immittance testing involves several key steps, each designed to gather specific information about the middle ear and auditory system. The following outlines the procedural steps:

  • Step 1: Otoscopic Examination The physician begins by examining the ear with an otoscope to assess the external ear canal and tympanic membrane for any visible abnormalities or obstructions that may affect the testing.
  • Step 2: Tympanometry A tympanometry device is then inserted into the ear canal. The device alters the air pressure within the canal, causing the eardrum to move. This movement is recorded and displayed as a tympanogram, which provides information about the eardrum's compliance and the presence of fluid or other issues in the middle ear.
  • Step 3: Acoustic Reflex Threshold Testing Following tympanometry, the same device is used to conduct acoustic reflex threshold testing. A loud sound is emitted into the ear, and the response of the stapedius muscle is measured. The softest sound that elicits a reflex contraction is recorded, indicating the threshold level.
  • Step 4: Acoustic Reflex Decay Testing In this step, a continuous tone is presented in the contralateral ear for 10 seconds at a level 10 decibels above the previously determined reflex threshold. The response of the stapedius muscle is monitored, and a decrease in amplitude of 50% or more within the 10 seconds indicates a positive test, which may suggest a retrocochlear lesion.

3. Post-Procedure

After the completion of acoustic immittance testing, the physician will review and interpret the results from the tympanometry, acoustic reflex threshold, and acoustic reflex decay tests. The findings will guide further diagnostic or therapeutic interventions as necessary. Patients may be advised on any follow-up appointments or additional testing based on the results. It is important for the healthcare provider to communicate the results clearly to the patient and discuss any implications for their hearing health or potential treatment options.

Short Descr ACOUSTIC IMMITANCE TESTING
Medium Descr ACOUSTIC IMMIT TEST TYMPANOM/ACOUST REFLX/DECAY
Long Descr Acoustic immittance testing, includes tympanometry (impedance testing), acoustic reflex threshold testing, and acoustic reflex decay testing
Status Code Active Code
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 7 - Physical Therapy Service, for which Payment may not be Made
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 2 - 150% payment adjustment does NOT apply.
Physician Supervisions 02 - Procedure must be performed under the direct supervision of a physician.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator STV-Packaged Codes
Type of Service (TOS) 1 - Medical Care
Berenson-Eggers TOS (BETOS) T2D - Other tests - other
MUE 1
CCS Clinical Classification 220 - Ophthalmologic and otologic diagnosis and treatment
AB Audiology service furnished personally by an audiologist without a physician/npp order for non-acute hearing assessment unrelated to disequilibrium, or hearing aids, or examinations for the purpose of prescribing, fitting, or changing hearing aids; service may be performed once every 12 months, per beneficiary
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
GA Waiver of liability statement issued as required by payer policy, individual case
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
PO Excepted service provided at an off-campus, outpatient, provider-based department of a hospital
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
25 Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service: it may be necessary to indicate that on the day a procedure or service identified by a cpt code was performed, the patient's condition required a significant, separately identifiable e/m service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. a significant, separately identifiable e/m service is defined or substantiated by documentation that satisfies the relevant criteria for the respective e/m service to be reported (see evaluation and management services guidelines for instructions on determining level of e/m service). the e/m service may be prompted by the symptom or condition for which the procedure and/or service was provided. as such, different diagnoses are not required for reporting of the e/m services on the same date. this circumstance may be reported by adding modifier 25 to the appropriate level of e/m service. note: this modifier is not used to report an e/m service that resulted in a decision to perform surgery. see modifier 57 for significant, separately identifiable non-e/m services, see modifier 59.
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
GN Services delivered under an outpatient speech language pathology plan of care
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
GX Notice of liability issued, voluntary under payer policy
GZ Item or service expected to be denied as not reasonable and necessary
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Date
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Notes
2011-01-01 Changed Short description changed.
2010-01-01 Added -
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