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Speech-in-Noise Testing: A Vital Component for Improved Hearing Aid Fittings and Happier Patients. Patty Niquette, M.A. Etymotic Research, Inc. pniquette@aol.com Iowa Association of Hearing Health Professionals April 30, 2004.
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Speech-in-Noise Testing: A Vital Component for Improved Hearing Aid Fittings and Happier Patients Patty Niquette, M.A. Etymotic Research, Inc. pniquette@aol.com Iowa Association of Hearing Health Professionals April 30, 2004
Hearing In Noise: The Hearing Aid User’s Perspective • Only 30% of hearing aid wearers reported satisfaction with their aids in noisy situations (Kochkin, 2002) • MarketTrak surveys conducted over the past 10 years revealed dissatisfaction with hearing aids in noisy environments (Kochkin, 1992; 1993; 1995; 1996; 2000; 2002) • Speech intelligibility in noise is still the #1 improvement sought in hearing aids (Kochkin, ILAA 2003)
If we want to improve satisfaction with hearing aids, we need to improve the user’s ability to hear in noise. How do you do this, if you’re not sure how much trouble the user is having in the first place?
What if you make everything audible, and the patient still has trouble hearing in noise? Then the problem is greater than audibility.
Signal-to-Noise Ratio (SNR) Loss • Similar to Hearing Loss, we define SNR Loss as the increase in signal-to-noise ratio required by a listener to obtain 50% correct, compared to normal performance
Why measure SNR Loss? • It’s the #1 complaint of hearing-impaired patients • It can’t be reliably predicted from the pure tone audiogram or other standard audiometric tests
SNR Loss =3 dB, 1 dB SNR Loss =9 dB, 9 dB Brian Taylor, HJ, January 2003:Patient APatient B 3F PTA =53,55 3F PTA =52, 53 WRS =80%,84% WRS =76%, 80% X X O O O X X X O O X X X O O O O O X X O X X O
Why measure SNR Loss? To predict how well your patients will do with their hearing aids. LAC, 2 Patients: • Best “referrer” < 1 dB SNR loss • “Hated to see in the waiting room” >17 dB SNR loss
Why measure SNR Loss? • SNR loss testing may instill your patients’ confidence in your skills more than any other test you perform • David Hawkins (Mayo Clinic, Jacksonville FL): patients report, “I've had lots of hearing tests, but this is the first time anyone really tested my hearing!"
Why measure SNR Loss? • To prescribe the appropriate solution to the hearing-in-noise problem for individual patients, based on their specific needs • To counsel patients appropriately regarding what to expect from given technologies, based on an assessment of their problem • Fosters realistic expectations • Oownership” of the hearing-in-noise problem
Why measure SNR Loss? • To increase your efficiency • To decrease unneccesary visits for the patient • We now have the tools that make the task quick and easy to implement in almost any setting
Factors affecting performance on any speech-in-noise test: • The SNR-50 depends on: • Speech materials used (sentences, spondees, etc.) • Background noise (shaped noise, multi-talker babble) • Test setup (sp/noise at 0° vs. sp/noise separated) • Audibility • Reverberation • Knowledge of the language • Age
SNR Loss Calculation • Example: • NH subject requires +2dB for 50% correct on a speech-in-noise test (SNR-50) • HI subject requires +12 dB for SNR-50 • SNR Loss for HI subject is 10 dB • SNR Loss is substantially independent of calibration and test material
Speech-in-Noise Test Construct: “Target Speech” Considerations • Monosyllabic words are not “real” speech • Sentences spoken with natural dynamics have greater dynamic range than monosyllabic words, and are a more valid representation of real speech • “Precompressed” speech is not natural • Sentence tasks can be efficient if a words-in-sentences scoring paradigm is used
Speech-in-Noise Test Construct: Background Noise Considerations • Speech-shaped noise is easy to control, but… • It doesn’t reflect amplitude and temporal characteristics of real speech • Results don’t necessarily generalize to the real world, especially for hearing aids that utilize compression • Patients rarely say that shaped noise sounds like background noise in the real world • Auditec four-talker babble (3 females, 1 male) = realistic simulation of a social gathering
SIN Test™ (1997) • IEEE sentences (high school language level), female talker • Auditec 4-talker babble • 5 sentences at each of 4 SNRs (15, 10, 5, 0) • 5 key words/sentence • Two presentation levels: 70 dB HL and 40 dB HL • Scored by plotting percent correct for each SNR on a graph, and interpolating the 50% point • 2 equivalent lists
QuickSIN™ Test (2001): • IEEE sentences, female talker, in 4-talker babble • 1 sentence at each of 6 SNRs (25, 20, 15, 10, 5, 0) • Scoring: SNR Loss = 25.5 – Total Correct • 12 equivalent lists; each takes 1 minute • 3 additional list pairs for research, where more lists are needed
“Standard” QuickSIN (tracks 3-20) • Setup: connect a CD player to the audiometer’s external input • Most (but not all) CD players work fine • Example of cords & plugs • Using calibration tone on Track 1, set the audiometer VU meter/s to “0” • If VU meters can’t be set to 0, adjust presentation level accordingly
Cable & Plug Adapters (Available from Radio Shack) • Cable, gold plugs (1): • #42-2483 (6 ft., $8) OR • #42-2550 (3 ft., $6) • Gold plug adapters (2): • #274-884 ($4 each)
“Standard” QuickSIN (cont.) • Speech and noise are presented together at prerecorded signal-to-noise ratios • Present the test through headphones • Monaural or binaural • 70 dB HL (for losses greater than 45 dB HL, present test at “loud but OK”) • I like to present one practice list, then three test lists (average the scores of the test lists)
Levels of Loudness 7. Uncomfortably loud 6. Loud, but OK 5. Comfortable, but slightly loud 4. Comfortable 3. Comfortable, but slightly soft 2. Soft 1. Very soft
Instructions • Imagine you are at a party. There will be a woman talking and several other talkers in the background. The woman’s voice is easy to hear at first, because her voice is louder than the others. Repeat each sentence the woman says. The background talkers will gradually become louder, making it difficult to understand the woman’s voice, but please guess and repeat as much of each sentence as possible.
SNR Correct 1. To have is betterthan to wait and hope. 25 5 2. The screenbefore the firekept in the sparks. 20 5 3. Thickglasseshelped him read the print. 15 4 4. The chairlookedstrong but had nobottom. 10 3 5. They toldwildtales to frightenhim. 5 1 6. A forceequal to that wouldmove the earth. 0 0 Total Correct = 18 SNR Loss = 25.5 – 18 = 7.5 QuickSIN Demo
Interpreting SNR Loss SNR LossCategoryTechnology Needs 0-2 dB Normal Omni or Directional Mics 2-7 dB Mild Directional Mics 7-15 dB Moderate Array Mic >15 dB Severe FM System
“Split-track” QuickSIN (separated speech & babble) • Can be used to verify effectiveness of directional microphones in SF • Speech and babble separated • Calibrate both channels • Target talker = Channel 1 • 4-talker babble = Channel 2 • Examiner sets presentation levels
Example 1: Separated Lists Scoring: 25.5 – Total Correct = SNR Loss
Example 2: Separated Lists Scoring: 15.5 – Total Correct = SNR Loss
QuickSIN Statistics: Comparing Two ConditionsQuickSIN manual, Table 4
Split-track QuickSIN • Use whatever setup you have (45/135 or 0/180) • Results reflect location of SF loudspeakers and the directional mic’s polar pattern • Consider mounting the “noise” speaker on the ceiling • Be aware of the limitations of any tests done in a sound booth • Compare omni to directional • Use as a demonstration tool
HF Loss Example (DBH) • Test under headphones • In this example, 1 list per condition was used • Standard QS: 9.5 • HFE QS: 7.5 • HFE-LP: 3.5 • Table 4 in QS Manual • 95% CI=3.9 • 80% CI=3.2 O O O O O O O
QuickSIN Use • Measure SNR Loss, unaided • As part of the diagnostic test battery • Use results to select amplification / ALDs • Basis for counseling re: realistic expectations • Measure SNR Loss, unaided vs. aided • In SF, at 70 dB HL, unaided then aided • Performance shouldn’t decrease in the aided condition
QuickSIN use (cont.) • Demonstrate aided benefit • Low presentation level in SF, unaided vs. aided • Demonstrate SNR improvements • 70 dB HL in SF, separate-track version • Determine need for HF amplification • Filtered tracks, 70 dB HL under earphones • Use as a prescreening tool for APD
BKB-SIN™ Test (in development) • Why develop another test? • Length of IEEE sentences problematic for elderly with auditory memory deficits • IEEE sentences too difficult for young children • Cochlear Americas: Binaural CI study
BKB-SIN™ Test • Bamford-Kowal-Bench (BKB) sentences in Auditec 4-talker babble • Shorter, simpler sentences (first grade language level) • 3 to 4 key words per sentence • Male talker; verbal “ready” cue spoken prior to each sentence • One sentence at each SNR of: 21, 18, 15, 12, 9, 6, 3, 0, -3, -6 dB
BKB-SIN Demo (List 6A) SNR Correct • A boyrandown the path. +21 dB 4 • The orange was verysweet. +18 dB 3 • He is holding his nose. +15 dB 3 • The newroad is on the map. +12 dB 3 • The boyforgot his book. +9 dB 3 • A friendcame for lunch. +6 dB 2 • The matchboxes are empty. +3 dB 1 • The familybought a house. 0 dB 0 • The ballbroke the window. -3 dB 0 • The pondwater is dirty. -6 dB 0 SNR-50 = 23.5 – TL Correct = 23.5 – 19 = 4.5
Age-related performance effects: an interesting analogy Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in what oredr the ltteers in a wrod are, the olny iprmoetnt tihng is that the frist and lsat ltteer be at the rghit pclae. The rset can be a ttoal mses and you can still raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by istlef, but the wrod as a wlohe.
Data Analysis, Children’s Data • Group kids by age: • 5-6 year olds • 7-10 year olds • 11-14 year olds
BKB-SIN Phase 4: Children’s Norms • Additional data is being collected by Gail Whitelaw, Ph.D., and colleagues at The Ohio State University • Sample will be taken from an area with lower average socioeconomic status than those of the previous sample • Goal is to average the scores to encompass a “normal” range of performance for children
Billing for Speech-In-Noise Tests • No CPT code exists for Speech-In-Noise Tests • It takes 2-3 years for a new code to be approved • Few new codes can be proposed each year • There are many codes “waiting in line” • CPT 92700: Unlisted ENT service or procedure • Description, purpose and literature substantiation required • Reimbursement is typically fair at best • An option: bill the patient for the procedure as a non-covered benefit • Must first tell patient the purpose of testing and the cost
Solutions for SNR Loss • Directional microphones • 3-5 dB improvement • Array microphones (Link-it) • 7 dB improvement over ITE omni mic • 10 dB improvement with two Linkits • FM systems
133 Chicago Area Hearing Aid Purchasers Cumulative Distribution of SNR Loss in Hearing Aid Wearers Half of all hearing aid wearers have an SNR Loss of 5 dB or greater!