Congenital Hearing Loss Rich Harward, Au.D. Utah Department of Health URLEND - Audiology
Blindness separates people from things,deafness separates people from people.Helen Keller
Path of Sound • Auricle / Pinna • External Ear Canal • Vibrates Eardrum • Vibration moves through Ossicles • Stapes vibrates Oval Window of Cochlea • Creates pressure wave in the fluid inside
Types of hearing loss • Sensorineural vs Conductive vs Mixed • Congenital vs acquired (prelingual vs post lingual) • Progressive vs non-progressive • Syndromic vs non-syndromic
Why is early identification of hearing loss important? • Hearing loss occurs more frequently than any other birth defect.
What Causes Hearing Loss? Environmental CMV meningitis rubella prematurity head trauma asphyxiation ototoxicity hyperbilirubin other infections Syndromic Stickler Neurofibromatosis Pendred Usher Waardenburg Branchio-oto-renal Jervell and Lange-Nielsen ~40% Congenital Hearing Loss ~30% ~60% Non-syndromic Autosomal dominant ~20% Genetic Autosomal recessive ~80% X-Linked ~70% ~1% <1% Mitochondrial
Otoacoustic Emissions (OAE) Automated Auditory Brainstem Response (AABR) How is newborn hearing screening done?
Disabilities That Occur with Deafness (%) Gallaudet Research Institute, Jan 2003
Delayed Diagnosis • Misdiagnosis • Permanently impaired speech and language skills • Reduced intellectual ability • Lowered adult earnings • More limited social skill development
Boys Town National Research Hospital Study of Earlier vs. Later 129 deaf and hard-of-hearing children assessed 2x each year. Assessments done by trained diagnostician as normal part of early intervention program. 6 Identified <6 mos (n = 25) 5 Identified >6 mos (n = 104) 4 3 Language Age (yrs) 2 1 0 0.8 1.2 1.8 2.2 2.8 3.2 3.8 4.2 4.8 Age (yrs) Moeller, M.P. (1997). Personal communication , firstname.lastname@example.org
Reading Comprehension Scores of Hearing and Deaf Students Grade Equivalents Age in Years Schildroth, A. N., & Karchmer, M. A. (1986). Deaf children in America, San Diego: College Hill Press.
Effects of Unilateral Hearing Loss Normal Hearing Unilateral Hearing Loss Math Keller & Bundy (1980) (n = 26; age = 12 yrs) Language Math Peterson (1981) (n = 48; age = 7.5 yrs) Language Social Bess & Thorpe (1984) (n = 50; age = 10 yrs) Math Blair, Peterson & Viehweg (1985) Language (n = 16; age = 7.5 yrs) Math Culbertson & Gilbert (1986) Language (n = 50; age = 10 yrs) Social Average Results 0th 10th 20th 30th 40th 50th 60th Math = 30th percentile By 3rd grade, the average child with unilateral loss is ~24 months behind his or her peers in math, language and social skills. Percentile Rank Language = 25th percentile Social = 32nd percentile
Controversial Hearing Loss Management Issues • Communication mode • Cochlear Implants • Unilateral hearing loss • Fluctuating / mild hearing loss • Central auditory disorders /auditory neuropathy • Progressive hearing loss / late onset HL