Audiology & Hearing aids › files › s-dabiri › Audiology - Students.pdf · Audiology (Clinical Applications) Sasan Dabiri, M.D. Assistant Professor Department of Otorhinolaryngology

Audiology(Clinical Applications)

Sasan Dabiri, M.D. Assistant Professor

Department of Otorhinolaryngology – Head & Neck Surgery

Amir A’lam hospital

Tehran University of Medical Sciences

Last Updated in February 2015

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG

Vestibular Evaluation

Audiology

Anatomy

AnatomyAudiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Physiology

• Auricle (pinna)• Sound gathering & localization

• External Ear Canal• Resonance (specific frequencies)

• Tympanic Membrane & Middle Ear• Impedance matching (air fluid)

• Cochlea• Mechanical energy Electrical energy

• Cochlear nerve• Conduction to CNS

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Classification

• Primary Audiologic Evaluation– Audiometry (subjective)

• Pure Tone Audiometry

• Speech Audiometry

– Acuostic Immittance (objective)

• Tympanometry

• Acoustic Reflex

• Advanced Audiologic Evaluation– Otoacoustic Emissions

– Auditory Brainstem Response

– Electrocochleography

• Vestibular Evaluation

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry

• Pure Tone Audiometry (PTA)

Sound Characteristics:• Intensity (SPL, HL) : decibel (dB)

• Frequency : Hertz (Hz)

Sound Threshold:• lowest signal intensity detected at

50% of presentations

Air conduction vs. Bone conduction

Air – Bone Gap (ABG)

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


– Normal

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


– Conductive

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


– Sensorineural

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


– Mixed

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


250 500 1000 2000 4000 6000 8000

Down to 25 dB Hearing Level = Normal

26 – 40 dB Hearing Level = Mild Hearing Loss

41 – 55 dB Hearing Level = Moderate Hearing Loss

56 – 70 dB Hearing Level =Moderately Severe Hearing Loss

71 – 90 dB Hearing Level =Severe Hearing Loss

Lower than 90 dB Hearing Level = Profound Hearing Loss

0

10

20

30

40

50

60

70

80

90

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry


Average of hearing = .5 + 1 + 2 + 4 KHz

4

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

AudiometryAudiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Right Ear Left Ear

Bone Conduction

Unmasked < >

Masked [ ]

Air Conduction

Unmasked ○ x

Masked ∆ □

Audiometry



– Speech Reception Threshold (SRT)

– Word Recognition Score (WRS)

(Previously named SDS)

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Audiometry



• Prevention of errors in Audiometry

– Comparison of mean PTA & SRT

– Appropriate follow up in asymmetry

– Attention to technical errors – Compatibility to examination

– Masking

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance

Immitance = Impedance + Admittance

• Tympanometry

– Tympanic membrane movement

– Applications:

• Middle ear function

• External canal volume


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance

Immitance = Impedance + AdmittanceImmitance = Impedance + Admittance

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type AN


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type AS

Ossicular fixation


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type AD

Atrophic TM

Ossicular

discontinuity


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type B

Glue in middle ear

Mass in middle ear

Perforation


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type C

Eustachian

dysfunction


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

– Type D

Scarred TM

Hypermobile TM


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

• Stapedial reflex

– Reflex threshold & Reflex decay


Cochlear Nerve

Superior OlivaryNucleus

Cochlear Nucleus

Facial Nucleus

Facial Nucleus

Facial Nerve

Facial Nerve

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Acoustic Immittance


• Tympanometry

• Stapedial reflex

– Reflex threshold & Reflex decay

– Appications:

• Evaluation of Auditory pathway

• Localization of Facial nerve lesion


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology

• Otoacoustic Emissions (OAE)

– Evaluation of cochlear function

– Applications:

• Neonatal hearing screening

• Auditory neuropathy

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology



Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology


• Auditory Brainstem Response (ABR)

– Evaluation of synchronized response of lower auditory pathway neurons

– 5 waves in diagram (I, II, III, IV, V)

– Applications:

• Evaluation of hearing sensitivity

• Otoneurologic evaluation

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology



Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology



• Electrocochleography (ECoG)


– Applications:

• Ménière’s disease

• Enhancing wave I in ABR

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Advanced Audiology



• Electrocochleography (ECoG)


Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology


• Electronystagmography

• Videonystagmography

• Caloric Test

• Vestibular Evoked Myogenic P. Test

• Rotatory Chair Test

• Posturography

Audiology

Anatomy

Physiology

Classification

Primary Evaluation

• Audiometry

• A.I.

AdvancedEvaluation

• OAE

• ABR

• ECoG


Audiology

Tinnitus - Definition

The perception of sound

in the absence of external stimuli

(tinnire means ringing in latin)

Tinnitus - Neurophysiology

Tinnitus - Classification

• Subjective Tinnitus:sound is only perceived by the patient (most common)

• Objective Tinnitus:sound produced bypara-auditory structures which may be heard by an examiner

• Non-pulsatile Tinnitus:

Perceived sound is continuous (most common)

• Pulsatile Tinnitus:

Perceived sound has cyclic non-continuous course that may be vascular or muscular

Tinnitus - Differential Diagnosis

Subjective

• Presbycusis

• Noise exposure

• Meniere’s disease

• Otosclerosis

• Head trauma

• Acoustic neuroma

Tinnitus

• Cerumen impaction

• Drugs

• Middle ear effusion

• TMJ problems

• Depression

• Hyperlipidemia

Pulsatile Tinnitus

• Venous Hum

• Benign Intracranial Hypertension

• Glomus Jugulare

• Glomus Tympanicum

• Arteriovenous Malformation

• Palatal Myoclonus

Tinnitus - Evaluation

• History Taking

Thorough and Complete Hx

• Physical Examination

– Head & Neck Examination

(including Otologic Examination)

• Paraclinic Evaluation

– Audiometry

– Imaging

Tinnitus - Management

• Medical

– Non-pharmacologic Behavioral Therapy (Retraining, Biofeedback)

Masking & Hearing aid

Electromagnetically

– Pharmacologic Antidepressants

Benzodiazepines

……

• Surgical (just for apparent otologic pathology)

Thanks for Your Attention

Documents

Audiology & Hearing aids › files › s-dabiri › Audiology - Students.pdf · Audiology (Clinical Applications) Sasan Dabiri, M.D. Assistant Professor Department of Otorhinolaryngology