Spain • Auditory cortex Cerebral Structures
Sup. Temp. gyrus
Supra marginal gyrus
Temp. Pole Brainstem & cerebral auditory tracts
MGB Aud. cortex
Int. capsule, sub lent. Lat. lemniscus Inferior colliculus Dorsal coch. nuc. SOC Ventral coch . nuc.
Acous. stria Spiril gang.
Aud. nerve Acous. stria http://www.geocities.com/medinotes/diagram_auditory_pathways.htm 80% THE CONTRALATERAL EFFECT Distorted 20% Speech Tests Grey & Dichotics White matter
AEP AEP
Sound/word
LE
Musiek Layers of Cortex
I II
III = 3 - 4 mm
IV
V
White matter Layers of cortex
• I. = cell poor zone (axons superfical, demdrites deeper in the layer) • II. = small pyramidal cells • III.= large pyramidal, & fusiform cells • IV.= mostly stellate cells • V. = cell sppyarse & dense layers (large pyramidal) • VI.= large pyramidal, complexly arranged Where is the auditory cortex ? Secondary vs. Primary Auditory Cortex ? Lateral Brain
From Celesia, 1976 Auditory Area of Cortex
B
C A
D
E
A=frontal lobe, B=parietal lobe, C=occipital lobe, D=temporal lobe, E=cerebellum 1=temp. pole, 2=Sylvian Fissure, 3=s. marginal gyrus, 4=angular gyrus, 5=s. temp gyrus From Waddington, modified by Musiek From Dublin (Gestalt) (Analytic) ltlat,. ven tiltricle Int. capsule thalamus
insula
MGB
Sup. Temp. gyrus
Middle temp. gyrus Projections to Auditory Cortex
(Secondary)
* Posterior n., Reticular n., ? Pulvinar = Aud. Thalamus Pathways to the Auditory cortex Internal, external capsules
SltilSupra lenticular
Sub lenticular
routes The Insula Temporal Plane (Rt.) 1. int. capsule 2. Ext. capsule 3. Insula 4. Heschl’ s 5. Planum temp. 6. Caudate 7. Thal amus 8. Lenticular proc. Intrahemispheric Transfer
Celesia, 1976 Asymmetries…………….. Temporal Lobe
(1) (2) Asymmetries of auditory cortex : Planum temporal & Heschl’s gyrus
Identification and labelling of HG and PT
Dorsaint-Pierre, R. et al. Brain 2006 129:1164-1176; doi:10.1093/brain/awl055
Copyright restrictions may apply. Perceptions of Electrical Stimulation of the Human Brain (Penfield & Perot) Vascular Anatomy Frequency representation
The classic view
The core - belt
M
core L belt
parabelt L H
(see Hackett) Frequency representation
The classic view
The core - belt
MiMapping on tthto the Human brain ? Types of Tuning Curves in Aud. Cortex AUDITORY CORTEX REORGANIZATION
X X X X X X X
low high
audiogram
cochlea
apical basal
X X X X X
X X audiogram X X
Recanzone et . al .
• Monkeys were trained for several weeks on freq. discrim. task • After training, tonotopic maps were established by recording multi-unit responses. • Frequency responses were compared to those o f con tro l mon keys
Intensity representation
• # of neurons • Firing rate • Inhibit ory – excita tory i n terac tion
Firing rate
intensity
Evans, 1965
• Gap detection – The physiologic response @ cortex
Stim.
Neural firing Modulated signals
• FM signals: best (modulation rate) response usually close to the characteristic frequency • AM : best reponse is 1- 50 Hz
» (Phillips) Phillips Corpus Callosum Right Left
Gestalt Analytic
(ventricles)
From Waddington, modified HUMANS
Compromised Compromised Compromised Compromised Localization and the auditory cortex Localization
ITD IIDI ID Contralateral effect = ablation, lesion studies EE, EI, II cells Auditory cortex ipsi vs. contralateral responses for localization
Firing rate 620 Hz
600 400 200 200 400 600 msec
Contralateral lead Ipsilateral lead t t t
Adapted form Teas 1976 Functional Imaging of the Auditory Cortex
Courtesy of Ken Hugdahl
Dichotic listening fMRI @ different Anatomical levels of auditory Cortex. Zattore….. Audiology
• Peripheral disorders • Central disorders Audiology Diagnostic & Rehabilitative • Behavioral tests • Electrophysiologic tests • Behavioral tests – Pure tone thresholds – Speech reception thresholds – Speech recognition Basic terms
• dB •Hz • SPL •HL •SL Basic Concepts
• Threshold – Least amount of sound necessary for a signal to be detected 50% of the time • Pure Tone – Singgqyle frequency tone (250-8000 Hz) – Air vs. Bone (250-4000 Hz) • Intensity Level The Audiogram
Frequency
125 500250 1000 2000 4000 8000
0 10
L 20 HH 30 40
ng in dB 50 ii 60
Hear 70 80 90 100 Degrees of Hearing Loss
Frequency
125 500250 1000 2000 4000 8000
NlhiNormal hearing 25
L Mild hearing loss HH 40 Moderate hearing loss 55 ing in dB rr Moderately- severe hearing loss
Hea 70 Severe hearing loss 90 Profound hearing loss Behavioral Measures: Air CdtiConduction
Frequency
125 500250 1000 2000 4000 8000
0 10 = Right
L 20 XXXX XX HH 30 X = LftLeft 40 50 ing in dB rr 60
Hea 70 80 10090 Behavioral Measures: Bone Conduction The vibrator is typically placed on the mastoid, but can be placed on the forehead. Beha vi oaoral M easueseasures: B on e Conduction Frequency
125 500250 1000 2000 4000 8000
0 < < < < < 10
L 20 XX> > XX >>>XX = Right AC HH 30 X = Left AC 40 50 ing in dB < = Right BC rr 60
Hea 70 > = Left BC 80 90 Bringing it Together
125 250 500 1000 2000 4000 8000
0 10 Cannot Hear
20 30 40 50 60 70 Can Hear 80 90 Types of Hearing Loss
• Conductive • SilSensorineural • Mixed
Martin & Clark, 2000 Conductive Hearing Loss
Frequency
125 500250 1000 2000 4000 8000
0 10 << < <<
L 20 HH 30 40 50 ing in dB rr 60
Hea 70 80 90 Sensorineural Hearing Loss
Frequency
125 500250 1000 2000 4000 8000
0 10
L 20 HH 30 40 <<< << 50 ing in dB rr 60
Hea 70 80 90 Mixed Hearing Loss
Frequency
125 500250 1000 2000 4000 8000
0 10
L 20 HH 30 << << 40 < 50 ing in dB rr 60
Hea 70 80 90 Modified Hughson-Westlake ThiTechnique • Pick an ear & begin at 1000 Hz • Start at a level above the threshold (Increase in 20 dB steps until you obtain a response) • Present tone
Bracketing rule: Down 10 & up 5 Hughson-Westlake Technique
Obtain a response, decrease by 10 dB
RESPONSE NO RESPONSE Continue to decrease Increase by 5 dB HL by 10 dB until no until receive a response response Hughson-Westlake Technique
• Repeat this until the criterion for threshold is met
• Remember: Criterion = 50%
• According to ASHA (1978), when 3 out of 6 presentations result in a response, threshold is achieved Behavioral Measures
• Speech Detection Threshold • Speech Reception Threshold • Speech Recognition/Discrimination – Word Recognition Score • Most Comfortable Listening Level (MCL) • Uncomfortable Listening Level (UCL) SDT
• Speech Detection Threshold – Sound Awareness Threshold (SAT) – Detection – Threshold • Lowest Level that speech can be detected or heard 50% of the time – Common Populations SRT
• Speech Reception Threshold – Reception/Recognition – Threshold • Softest level that stimuli can be repeated/understood 50% of the time – Populations SDT/SRT
• Stimuli – Spondaic Words (Spondees) SRT/SDT
• Measure of Pure Tone Test validity – Comparison to PTA (what you have all been waiting for!)
• Reference for other measures WRS
• Speech Recognition Score – Evaluates speech at suprathreshold Levels • 40 dB SL (PTA or SRT)
– How well is speech understood at conversational Levels • 65 dB HL WR Stimuli NU 6 Terms
• Admittance/Compliance
• IdImpedance
• Immittance Healthy Middle Ear results
High A B
ance B
Admitt C C Low A
Negative Pressure Positive Pressure Atmospp()heric (0) Pressure Peak Admittance when pressure ME = pressure EE Parameters
• Maximum Admittance or Compliance – Mmho or mL
• Pressure at Maximum Admittance – daPa
• Ear Canal Volume – cubic centimeter Admittance
Maximum Admittance
Normal Values: 0.25 - 1.7
http://www.maico-diagnostics.com/eprise/main/Maico/Products/Files/MI24/Guide.Tymp.pdf Pressure
Normal Value: >-150 Normative Values
Value
Max Admittance .25 to 1. 7
Middle Ear Pressure >-150
Ear Canal Volume 0.3 to 2.0
Note: combined adult and pediatric norms Jerger Types
TYPE A
TYPE B
TYPE C Discriminating Fluid from PfPerforati on • Ear Canal Volume
Fluid = Normal ECV Perforation = Large ECV Summary - Tymp Interpretation
Peak Ear Canal Volume Type A Present and Normal occurs around Volume 0 Type B ( fluid) No Peak Normal Volume Type B (perf) No Peak Large Volume Type C Negative Normal Peak Volume Disorders of the Middle Ear • Otitis Media (OM) – Infection of the middle ear – Most common cause of CHL – Affects all ages, but especially kids Diagnostic Considerations
• Hearinggg Loss Configuration
• Perforation Present? Disorders of the Middle Ear
• Otosclerosis – Formation of new bone growth around the footplate of the stapes Diagnostic Considerations
• Progressive CHL • Carhart’s Notch • Schwartze Sign • Tympanometry Presbycusis
• Hearing loss due to aging
Noise Induced Hearing Loss
• High levels of noise can cause hearing loss.
– Temporary Threshold Shift (TTS)
– Permanent Threshold Shift (PTS) Noise Induced Hearing Loss Ototoxicity
• Damage to the ear due to chemical agents such as drugs Meniere’ s Disease
• Endolyypmphatic Hydrops
• Caused by an excessive amount of endolymphatic fluid that distends Reissner’s membrane Meniere’ s Disease Acoustic Neuroma
•“vestibular schwannoma” Acoustic neuroma
Frequency
125 500250 1000 2000 4000 8000
Spch recog. 0 10 O O O O O O 100% RE X X L 20
66% LE HH 30 X 40 X
ng in dB 50 ii X 60
Hear 70 80 X 90 100 Acoustic neuroma: symptoms
• Unilateral h. f., s/n hearing loss • Gradual, progressive • UiltUnilatera ltiitl tinnitus • Imbalance • Difficulty understanding spch (phone) Elec trop hys io log ic tes ts Time Based AEPs
ABR MLR (Late Potentials) P3
[.5µV P2
(MLR) (ABR) V Pa Pb P1 ?
N2 Na Nb N1
0 37.5 75 150 300 msec .5 microvolts
IV-V IIIIII
01msec 0 .5 microvolts
IV-V IIIIII
Acoustic neuroma
010 msec MS Case
Otoacoustic Emissions (OAEs)
OAE History
• Tommy Gold (1949) ! • David Kemp (1978) • Kemp” s pat ent on TEOAE s & i mpact
Normal hearing, 12.9 dB SPL, 93% Correlation
Hearing loss all freq., level = 2.1 dB SPL, Correlation = 17 %
0 20 msec Central Auditory (Processing) Disorder
HISTORY
BOCCA & Colleagues, 1954
Myklebust, 1954 Is the audiogram useful in central auditory disorders ? Paradoxical Left Ear Deficits - when corpus callosum is involved. Etiologies of CAPD
• Mass lesions • Extrinsic brain damage (trauma, metabolic, Lyme dis,,y heavy metal, ,p herpetic encep halitis etc. • Epilepsy (Landau Kleffner) • Vascular lesions • Developmental disorders (ADHD , Lang., dyslexia, other LD) • Degenerative • Deprivation • Aging • Surgical effects • others See Bamiou et al. 2001 Key Test Procedures: Behavioral Dichotic Listening What is it ??? Norms:
7-8 y, 55, 70 % 8-9 y, 65, 75 % 9-10 y, 75-80 % 10-11 y, 78-85 % 11y-A, 90-90 % (Musiek)
Frequency Patterns Pin he iro & Ptace k, 1971; Mus ie k Pin he iro Baran 1987
HIGH HIGH
1122 Hz yy enc
uu LOW
880 Hz Freq
[200 msec] 150 msec
Time
6 sec
20 msec
1.
5ISI5 sec ISI 2 msec 10 msec 2.
5 sec ISI
3. No Gap Mean % Psychometric Functions Correct Psychometric Function 100 90 80 70
60 Control RERE Control LE 50 Neurological RE 40 Neurological LE 30 20 10 0 c c c c c c ec e e e ec e e ec ec e s s s s ms m m ms ms m ms ms ms m 2 3 4 5 6 8 10 12 15 20 Gap Duration TRACKING A FUSED IMAGE 0 Millisecond Delay (Cranford, Moore 1990)
0.3 Millisecond Delay
trailing leading
0.8 Millisecond Delay trailing leading
From Cranford et al (modified) NORMAL
Key Test Procedures: Electrophysiological Normal MLR and 3 MLR with CilLiCortical Lesions
N1, P2 complex
P2
N2 N1
CASES [Musiek] [ difficulty: reading, with directives, hrng in noise]
Case 3.1 Digits CVs D. Rhym D. Patt. F. Patt. LPFS 100 X
% X
50
O O XOX O 0 Case 3.1 Special mention
• Tinnitus, hyperacusis, & hallicinations HiAid&ChlIltHearing Aids & Cochlear Implants Parts of a Hearing Aid
mihicrophone amplifier receiver
Battery Optional VC
Fall 2008 135 Types of Hearing Aids ______• bdbody modldel microphone and amplifier on body portion receiver at ear level and separated by a cord
• eyeglass moddlel microphone on bow of eyeglass with receiver behind the ear, resembling a BTE
Fall 2008 136 dept.kent.edu/.../first/dalberg_d14.htm www.entnet.org/museum/funfact4.cfm Types of Hearing Aids ______
• BTE behind - the – ear
• ITE in - the - ear
• ITC in – the - canal
• CIC completely in the canal www.widex.com
•Open fit hearing aids? Fall 2008 137 Cochlear Implants
Part II Cochlear Devices
ESPrit 22 Spectra ESPrit SPrint
ESPrit 3G Freedom Electrode Array Current Speech Processors
ESPrit 3G Freedom • Whisper setting • Sweat & Water Resistant • Light weight • Built-in telecoil & FM option • Wide array of fashionable colors •4 Programs • Built-in telecoil • Volume & Sensitivity Controls •NRT available • DlMihDual Microphones • LCD Screen • Lockable Controls • NRT available • Smart Sound • Myths and reality for CIs