Transcript PPT only
!☻☻!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