Base of Audiology Anatomy and Physiology of the organ of hearing. Examinations of hearing losses with different origin.

UNIVERSITY of SZEGED Department of Oto-Rhino- Laryngology and Head- Neck Surgery Base of Audiology Anatomy and Physiology of the organ of hearing. Examinations of hearing losses with different origin. Dr. habil. József Géza Kiss Research Professor

Structure of the ear I.

Structure of the ear II.

The cochlea

The organ of Corti I.

The organ of Corti II.

The organ of Corti III.

Frequency distribution inside of the cochlea topology Traveling wave Traveling wave

How the outer hearing cells are functioning

The sound Source of sound Propagation medium

The sound Source of sound: vibration of elastic bodies causes pressure difference (for example: tuning fork, string, vocal chords) Propagation medium: vibration of the sound source spreads as a pressure wave (longitudinal wave) Physical parameters: frequency, amplitude, phase, etc.

The sound are longitudinal wave

The spread of sound

Period time The sound I t[s] Wave lenght I x[m]

Frequency(f or ν) Periods taking place per time unit Unit: f=1/s = 1 Hz We hear different sounds with different frequencies as different pitched sounds.

Amplitude Intensity of sound Intensity of sound: Magnitude of sound energy passing perpendicularly through one unit of the spreading surface: [I] = 1 W/m 2 Amplitude: air-pressure change caused by vibration: [P] = 1 Pa Formula: I = P 2 /d*v d: medium density, v: spreading velocity of sound

The decibel scale (db) Bel: log 10 of two sound intensities: 1 Bel = 10 db (SPL = Sound Pressure Level) Base level: the human ear can sense it at 1 khz: I 0 = 10-12 W/m 2, P 0 = 20 µpa Discomfort level: I ucl = 1 W/m 2, P ucl = 20 Pa Dynamic range: log 10 (10-12 ) = 120 db

Sound and wibration

Doppler-effect

Vibration type

Superposition

Harmonic waves

The vibrations of the membranes

The vibrations of the eardrum

Vibration of the eardrum and the ossicular chain (500 Hz)

Vibration of the eardrum and the ossicular chain (2000 Hz)

Sensitivity of the ear

db SPL and db HL

Sensation of sound Loudness Phon-scale: equal loudness curves (1 khz) Son-scale: comparative loudness 40 phon = 1 son Pitch mel scale

Complex sounds pure tone tone noise

Audiometry Subjective audiometry Objective audiometry

Subjective audiometry Pure-tone audiometry threshold audiometry above threshold examination examination of recruitment Fowler-test SISI-test examination of adaptation Békésy-audiometry Speech-audiometry Speech-threshold examination (numbers) Speech recognition examination (words)

Normal audiogram (Right) Jobb (Left) Bal db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Sensorinaural hearing loss db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Noise-induced hearing loss db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Presbyacusis db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Incipient Meniere disease db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Advanced Meniere disease db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Conductive hearing loss db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Otosclerosis db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Mixed type hearing loss db -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 60 125 250 500 1000 2000 4000 8000 Hz

Conductive hearing loss % számpróba numbers szópróba words 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 db

Sensorineural hearing loss % számpróba numbers szópróba words 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 db

Sensorineural hearing loss with discrimination loss % számpróba numbers szópróba words 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 db

Sensorineural hearing loss with rollover recruitment % számpróba numbers szópróba words 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 db

Objective audiometry Tympanometry Otoacoustic emission Auditory evoked potentials

Tympanometry Dinamic complianceexamination Statik compliance-examination Stapedius-reflex test Tuba-function test

Tympanometer

The stucture of the tympanometer

Acoustic impedance

Tympanogram

Multifrequency tympanometry

Multifrequency tympanometry LEFT

Multifrequency tympanometry RIGHT

Multifrequency tympanometry

Stapedius reflex ipsilateral contralateral

Reflex decay

ARLT ipsilateral contralateral

Otoacoustic emission Spontaneous otoacoustic emission (SOAE) Evoked otoacoustic emission (EOAE) transient EOAE (TEOAE) stimulus frequency emission (SPOAE) distortion product otoacoustic emission (DPOAE)

Spontaneous otoacoustic emission

Transient otoacoustic emission

Distortion product otoacoustic emission

F1 M F2

Distortion product otoacoustic emission

Distortion product otoacoustic emission (F 1 *F 2 ) 1/2

Auditory evoked potentials Cochlear evoked potentials Brainstem evoked potentials Cortical evoked potentials

Auditory evoked potentials Electrocochleographia (ECoG) Brainstem Evoked Response Audiometry (BERA) Cortical Evoked Response Audiometry (CERA)

Auditory evoked potentials Early evoked potentials (ECog, BERA) Middle latency responses(mlr) Late evoked potentials (CERA, SVR) Contingent negative variation (CNV)

Auditory evoked potentials transient potentials (ON) sustained potentials cognitive potentials

Averager technic without stimulus with stimulus

BERA examination Signal generator GAIN Display / Printer A/D converter, averaging GAIN PRE- GAIN

BERA examination

Condensation, rarefaction

The type of the stimuli

The setup of BERA examination

The setup of the stimulus

The parameters of the BERA waves

The localisation of the BERA waves

The ear-lobe electrode

Amplitude 4 electrode, ipsilateralis 800.00 700.00 Amplitúdó [nv] 600.00 500.00 400.00 300.00 200.00 100.00 0.00 0.00 2.00 4.00 6.00 8.00 Latency Latencia [ms] L.I. L.II. L.III. L.IV. L.V.

Amplitude [nv] 4 elektrode, contralateralis 800.00 700.00 Amplitúdó [nv] 600.00 500.00 400.00 300.00 200.00 L.I. L.II. L.III. L.IV. L.V. 100.00 0.00 0.00 2.00 4.00 6.00 8.00 Latency Latencia [ms]

Amplitude [nv] 3 electrode 700.00 600.00 Amplitúdó [nv] 500.00 400.00 300.00 200.00 L.I. L.II. L.III. L.IV/V. 100.00 0.00 0.00 2.00 4.00 6.00 Latency Latencia [ms]

BERA waves in case of different stimulus rate (normal) 64 Hz 52 Hz 40 Hz 28 Hz 16 Hz

BERA waves in case of different stimulus rate (pathological) 64 Hz 52 Hz 40 Hz 28 Hz 16 Hz

Acoustic neurinoma

Cochlear laesio

Cochlear disturbance

Brainstem disturbance

ASSR: Auditory Stady-State Response

Superpozition

The Cortical Auditory Evoked Potential (CAEP) HearLAB Cortical Evoked Response System The end of the road Auditory cortex orientation NAL: Dillon, Van Dun, Carter, Gardner-Berry NAL: Dillon, Van Dun, Carter, Gardner-Berry

CAEP The main components of cortical evoked potential are the P1-N1-P2 complex. As we know the P1 wave represented in the deepest layer IV of the neurons activity in the secondary auditory cortex. The N1-P1 complex represented neurons activity in the other upper layer (primary and secondary auditory cortex).

CAEP Infants Adult P2 10 µv 5 P µv 5.0 2.5 P1 N1 0-5 N 0.0-2.5-100 0 100 200 300 400 ms 500 600 0 100 200 300 400 500 600 NAL: Dillon, Van Dun, Carter, Gardner-Berry NAL: Dillon, Van Dun, Carter, Gardner-Berry

NAL: Dillon, Van Dun, Carter, Gardner-Berry

Hearing genetics Deaf children 1/1000 birth Assessing the quality of hearing is a demanding task with infants and in childhood. Unknown 25 % Acquired 25% Genetic origin 50% Yet it it is very important as the earlier we begin with the rehabilitation the better are the results (social integration, etc). Autosomal recessive 75-85% Nonsyndromic 70% Autosomal dominant 15-25% Syndromic 30% X-linked 1-2% HELP: Molecular biology!! 35 delg 50% Other recessive 50% GVOP-3.1.1-0498-2004-05/3.0 GENE PROTEIN GENE PROTEIN GJB2 BETA-2 GAP JUNCTION PROTEIN GJB6 BETA-6 GAP JUNCTION PROTEIN 12SrRNA Sensitivity to ototoxic drugs KCNQ4 K + transporter protein COCH cochlin SLC26A4 pendrin (anion transporter) GJA1 ALFA-1 GAP JUNCTION PROTEIN POU3F4 transcription factor 4 GJB3 BETA-3 GAP JUNCTION PROTEIN MYO6 unconventional myosin-6

Dried Blood Spots & dhplc SIBLINGS! -20-10 0 10 20 30 40 50 60 70 80 90 100 110 120 12SrRNA (TRNS1-TRND) Right 60 125 250 500 1000 2000 4000 8000-20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Left 60 125 250 500 1000 2000 4000 8000-20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Right 60 125 250 500 1000 2000 4000 8000-20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Left 60 125 250 500 1000 2000 4000 8000 12SrRNA (TRNS1-TRND) & KCNQ4