Management of Unilateral Hearing Loss for Audiologists and Speech Pathologists

1. Management of Unilateral Hearing Loss for Audiologists and Speech Pathologists Joey Ford, M.S., CCC-A Megan Friedman M.S., CCC-SLP, LSLS Cert. AVEd

2. 1978 Northern & DownsHearing in Children • Audiologists and otolaryngologists are not usually concerned over such deafness [unilateral], other than to identify its etiology and assure parents that there will be no handicap.

3. What has changed since 1978 • In the 1980s research really got going in this area. • Fowler, 1960; Harford & Barry, 1965 • Golas & Wark, 1967; Green & Henning, 1969 • There has been a steady stream of research since the 1980s showing that UHL causes delays and challenges in many areas.

4. Current Issues • Earlier identification • Birth vs. school age • Little consensus among professionals • Whether to aid at all or how to aid • Little research on when to aid • Is early better, if so, how early

5. Evidence Based Practice • Evidence Based Practice is ever changing • New research • Overwhelming evidence of the detrimental effects • New technology • Cochlear Baha, Oticon Medical Ponto and ear-level FM • More experience • Patients who are successful or unsuccessful with each technology and families who say, “I wish we had done this sooner.”

6. JCIH 2007 Position Statement • Infants and young children with unilateral hearing loss should also be assessed for appropriateness of hearing aid fitting. Depending on the degree of residual hearing in unilateral loss, a hearing aid may or may not be indicated. Use of “contralateral routing of signals” amplification for unilateral hearing loss in children is not recommended (American Academy of Audiology, 2003). Research is currently underway to determine how to best manage unilateral hearing loss in infants and young children.

7. Impact of Unilataral Hearing Loss • Localization • 2 ears work together to find the source of sound • The lost cell phone effect • Binaural Squelch • The ability of 2 ears to “tune in” to a sound • The cocktail party effect

8. Effects of Unilateral Hearing Loss • Binaural summation • Two ears hear sound at a quieter level than each ear individually. • This is important for those of us with normal hearing to remember. • Head Shadow Effect • Lateralized sound is received to one ear as a direct signal, the other ear is in the “head shadow” • Low pitch sounds wrap around the head easier than highs

9. UHL in the Real World • Speech/Language • Cognitive • Social • Psychological

10. McLeod, Upfold, Taylor, 2008 • Self-reported difficulties of adults with UHL • Emphasis on post-surgical vestibular schwannoma • These adults reported significant difficulty • Hearing in background noise • Hearing when someone was on their “bad side” • Localizing sound • They also reported more difficulty even when sitting directly across the table from someone.

11. Priwin, et al, 2007 • 57 subjects aged 3 to 80 with UHL (max cond) • Conversation in quiet • 26% had slight to moderate difficulty • Conversation with many people • 77% slight to moderate difficulty; 14% severe • Conversation with one person in traffic noise • 63% slight to moderate; 19% severe • Localization • 47% slight to moderate; 37% severe

12. Signal-to-noise ratio • Normal hearing children require a greater SNR than normal hearing (NH) adults to discriminate speech (Lieu, 2004). • Auditory cortex not fully developed • better language base • Children with UHL require a greater SNR than children with NH (Ruscetta, et al, 2005). • Think about your child’s classroom. • A child at recess • A child at Pump It Up or Chuck E. Cheese

13. Speech and Language • Shepard et al., 1981 • 1250 children in Iowa with hearing loss • Academic records were reviewed • Preschool through high school • Categorized by degree and type of loss

14. Shepard et al., 1981 • For children with minimal hearing loss • IQ and achievement test scores were only slightly reduced compared to normal hearing peers, if at all. • Large gap between language age and chronological age, which increased with grade level • By age 8, the vocabulary of some of these children was as much as 3 years behind that of their normal hearing peers.

15. Shepard et al., 1981 • Specifically, those with UHL exhibited • Smaller vocabulary • Less complex sentence structure • Incidental learning • Over hearing

16. Davis, et al., 1986 • Evaluated social, academic and communication status of 40 children age 5-18 with losses from mild to moderately severe. • Found that their scores on standard audiologic speech perception tests was highly correlated with degree of loss. • Similar correlation was not seen between degree of loss and several language measures. • Corroborated by Bess & Tharpe 1986, for reading, math and spelling scores of children with unilateral loss only.

17. Educational/Cognitive Impact • Bess, et al., 1998 • Reviewed the records of 1228 children in grades 3, 6 and 9. • 5.4% of those children had minimal hearing loss • 30% of the 3rd graders with minimal hearing loss had repeated a grade • By 9th grade, 50% had repeated a grade

18. Bess and Tharpe 1986 • 60 children with unilateral SNHL • Reviewed medical & educational records • Mean age of ID 5.5 years • Etiology: 52% unknown, 24% viruses, 15% meningitis, 8% head trauma • Of the 60 children • 35% had failed at least one grade • 13% got resource help one or more years • 20% exhibited behavior problems per teacher report

19. Educational/Cognitive Impact • Culbertson & Gilbert, 1986 • Found significant differences between IQ scores of children with severe to profound unilateral SNHL and those with mild to moderate unilateral SNHL.

20. Multi-Tasking • McFadden & Pittman, 2008 • 10 kids with minimal loss/10 with normal hearing • Unilateral, mild bilateral or high frequency • Categorized common words (primary task) while completing dot-to-dot games (secondary task)

21. McFadden & Pittman, 2008 • The dot rate of both groups decreased similarly when the primary task was introduced • The hearing impaired kids performed significantly worse than the normal hearing controls on the word categorization • The children may be unable to draw resources from other tasks to respond to a difficult listening situation. • They also may be unable to prioritize tasks.

22. Psychosocial Impact • Multiple studies going back to Giolas & Wark, 1967, report psychosocial sequelea of unilateral hearing loss. • Embarrassment, helplessness, withdraw, aggression, frustration and isolation • Stein, 1983 • Teachers and parents rated behavior • 42% aggression and withdraw • 37% lower than peers on interpersonal and social adjustment

23. Psychosocial Impact • Bess et al, 1998 • 6th and 9th graders with minimal hearing loss • COOP (Cooperative Information Project Adolescent Chart Method) • Assess physical, emotional and social functioning • Found significantly more dysfunction for tweens with minimal hearing loss than their normal hearing peers • Less energy • Tired more frequently • Stress • Social support • Self-esteem

24. Psychosocial Impact • Borton, Mauze & Lieu, 2010 • Children 6-17 years and their parents • Health Related Quality of Life survey • Survey had a control group of NH and those with bilateral loss • Focus groups for those with UHL

25. Psychosocial Impact • Found that children with UHL had significantly more variance in the social functioning score than children with normal hearing or those with bilateral loss. • Both parents and children with UHL rated social functioning lower than children with normal hearing or bilateral loss.

26. Psychosocial Impact • Focus groups found • Children didn’t notice differences as much as their parents did. • Parents suggested that difficulties got worse as their children aged and got into sports, etc. • Parents felt that teachers were not educated about UHL and their children suffered as a result. • Assistive technology was seen as a barrier to being “normal”.

27. Psychosocial Impact • Focus Group discussion • “[Sometimes I have] hollow moments, where there’s not really anything I can hear. A lot of times I stare off into space, which doubles not being able to hear. So, if I’m not paying attention and there is a lot of noise around or if I’m just not expecting someone to talk to me, I just go completely deaf. • Listening Effort

28. Psychosocial Effects • Bourland-Hicks & Tharpe, 2002 • Examined listening effort and fatigue in children with minimal to moderate loss • Compared to normal hearing peers there was no difference in fatigue, but significant difference in listening effort for both quiet and noise

29. Right vs. Left Differences? • Sininger & de Bode, 2008 • Auditory areas of the right hemisphere (left ear) are specialized for spectral processing of tonal stimuli and music. • Areas of the left auditory hemisphere (right ear) are primarily for processing temporally complex and rapidly changing stimuli like speech. • Lefties can be opposite (only righties in study) • Males more often than females are opposite • men=women in study

30. Sininger & de Bode, 2008 • Used gap detection testing of tonal stimuli and noise stimuli in each ear independently • The right ear showed an overwhelming advantage for noise. • Left ear a smaller advantage for tones. • The smaller gap in milliseconds was required to detect a change. • True for normal hearing or unilateral loss.

31. Sininger & de Bode, 2008 • Contralateral ear compensation • Occurs to some degree in late onset loss • Does not occur in congenital/very early onset loss • Sininger & de Bode, 2008

32. Sininger & de Bode, 2008 • Children with unilateral loss who have failed at least one grade at school are 5 times more likely to have right ear loss. • Oyler, et al., 1988 • Bess, et al., 1986 • Klee & Davis-Dansky, 1986

33. Right vs. Left Differences • Niedzielski, et al, 2006 • Evaluated 64 children with UHL • Mean age was 11 years • Both those with right loss and left loss achieved average intelligence on a full scale IQ test. • But, if you look at the scores from each subtest, significant differences exist.

34. Niedzielski, et al, 2006 • Those with right-sided loss scored signficantly lower on the verbal test compared to those with left-sided loss. • Most pronounced in the subtests of similarities, vocabulary and comprehension. • Smaller range of concepts, lower skills for learning verbal material and smaller abilities to use acquired knowledge in everyday situations.

35. Niedzielski, et al, 2006 • Those with left-sided loss scored more poorly on the non-verbal scale. • Particulary in the subtests of block design and object assembly. • Poorer abilities for analyzing, synthesizing, visual memory, spatial imagination and visual-motor coordination.

36. Management Options • No technology, self advocacy, coping skills • Hearing Aid • Conventional aid for aidable loss or CROS • FM system • Ear level • Soundfield • Cochlear Baha or Oticon Medical Ponto • Cochlear Implant – maybe down the road

37. No Assistive Technology • The most popular option until recently • Advantageous positioning • Controlling background noise • Asking for repeats • Utilizing other assistive devices like tape recorders in lectures or borrowing a friends notes

38. Hearing Aid • Conventional Aid • Moderately-severe or better hearing • Use when appropriate • Classroom • Dinner party • Group Discussion • Include auto noise program when possible • High non-use rate

39. CROS Hearing Aid • Does provide sound from the impaired ear • Requires a hearing aid on the normal hearing ear, as well • Aid on the normal hearing ear is quite large including DAI door and FM receiver • High non-use and return rate

40. FM system • Designed for classroom use • Does very well for it’s intended purpose • One speaker • Improvement in signal to noise ratio • Requires 2 users • Speaker and listener to use the equipment consistently and correctly • Positioning of mic • Correct settings • Jewelry, clothing noise, restroom breaks, aside conversations

41. FM Options • Soundfield • Benefits teacher and students with and without loss • Stationary • Desktop • Benefits one or a few students • Portable, but with limitations • Ear level • Very portable and discreet

42. Ear Level FM

43. Ear Level FM

44. Baha • Can be implanted age 5 and over • Can be worn on hard or soft headband • Provides mic and stimulation on the same side • Provides “pseudo stereo hearing” • Can be used with any degree of conductive loss or profound unilateral sensorineural loss • User is in control of use, volume & program

45. How do Baha & Ponto work?

46. Baha/Ponto

47. Baha Abutment

48. Linstrom, Silverman & Yu, 2009 • 7 adults with adult onset profound UHL • Implanted with Baha Compact • 20 adults with normal hearing • Goal=examine long-term efficacy • Speech recognition in noise • Subjective satisfaction • Assessed at 1 month, 6 months, 1 year post-Baha

49. Linstrom, Silverman & Yu, 2009 • HINT • Noise in the front, speech to each side • Speech in the front, noise to each side • Noise at 65 dBA • Significant advantage with Baha when speech was lateralized to the affected ear • SNR improved by 3.9 dB in directional mode • SNR improved by 3.1 dB in the omnidirectional mode • For a performance-intensity function of 10%/dB the omnidirectional Baha yields a 39% gain in speech intelligibility and the directional 31%.

50. Linstrom, Silverman & Yu, 2009 • The Baha had a disadvantage over the unaided condition when noise was delivered to the affected ear, especially in omni mode. • The disadvantage was not as great as the advantage seen in the opposite condition. • This is a point for patient and family counseling.