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!☻☻!Disorders Friday!?!
Or Stuck in the middle with Speech
Chapter 7 & 8 Mencher for next
Quizette (Oct 29)
Otitis Media

Symptom
(Chap 6 in Mencher)
• Sudden pain (< 24 hours)
• Moderate to profound hearing loss (1 –
14 days)

Population
• Respiratory Infection
• Diver/High pressure environment

Diagnosis
• Acute otitis media serous


Serous fluid (produced in the middle ear)
built up
Eustacian tube blocked by resp. infection
• Self resolve or grommet

Chronic otitis media serous
• Children
• Glue in ear, must aerate
Masking Speech

SNR = signal to noise ratio
• 0 dB SPL SNR -> 1 to 1 levels
• -10 dB SPL SNR -> Signal 10
dB less intense than noise

Hearing aid benefit
• Boost signal in quiet
• Improve SNR 0 to 20 dB SPL
(‘good’ = 8 dB)

Directional, number of
microphones, algorithms for
suppressing noise
What kind of Noise?

Energetic Masking
• Gaussian Noise or specific frequencies

Broad or partial mask of signal
• No semantic content
• Continuous, powerful mask

Informational masking
• Multiple talkers
• Competing semantic content
• Partial energetic mask, discontinuous

Dependent on speech envelope
How does masking affect hearing?

Test: comprehension of
nonsense sentences
• ‘The house flew the kitchen’
• Informational vs. Energetic
masker

Spatial separation of
masker & signal
• 0˚ to 180˚
• PREDICTIONS


Demo: masking speech
Unilateral hearing loss on
Speech?
Otitis Media

Symptoms
• Frequent ear infections


Initially acute
Pain & discharge
• Conductive hearing loss

Population
• Aural surgery in youth
• Crowded living conditions/large family

Diagnosis
• Chronic Suppurative Otitis Media

Perforated tympanic membrane
• Did not heal properly after surgery?
• Inflammation of Mucosa


High risk for infection
May cause granulation of Media
• Drainage & antibiotics may be required
• If severe tympanoplasty
‘Hearing’ Speech with Dyslexia

Traditional dyslexia
• Normal intelligence & sensory ability
• Difficulty Reading, Writing & Spelling


Visual dysfunction
New View on Dyslexia
(Wallace & Flowers, under review)
• Multisensory matching difficulties
• Exp: Which of two flashes occurred first


With/without coincident ‘beep’
Change latency of visual flash relative to beep 50 –
400 ms
• Result: Dyslexics performance is enhanced
over greater latencies (up to 350 ms)

Disturbed multisensory matching
Otitis Media Ramifications

Social consequences
• Hearing loss (frustration, etc)
• Avoidance of pressurized environments

Local consequences
• Erosion of the long process of the Incus
• Erosion into labrynth (semi-circular
canals) & fistula