The Words-in-Noise Test (WIN): English and Spanish

Transcription

1 The Words-in-Noise Test (WIN): English and Spanish Rachel McArdle, PhD Chief, Audiology and Speech Pathology Service, Research Career Development Awardee, VA RR&D Bay Pines VA Healthcare System, Bay Pines, FL Mitzarie Carlo, AuD, PhD Assistant Professor, School of Health Professions University of Puerto Rico, San Juan, Puerto Rico Richard H. Wilson, PhD Senior Research Career Scientist VA Medical Center, Mountain Home, Tennessee

2 Acknowledgments This material is based upon work supported by the Department of Veterans Affairs, Veterans Health Administration, and Office of Research and Development, Rehabilitation Research and Development Service.

3 Disclaimer The contents of this presentation do not represent the views of the Department of Veterans Affairs or the United States Government.

4 Bay Pines VA Healthcare System

5 Motivation to develop a new test Carhart & Tillman (1970) urged the development of a quick clinical speech-innoise test

6 Why measure speech-in-noise in an audiologic evaluation? difficulty understanding speech in background noise.

7 Why measure speech-in-noise in an audiologic evaluation? a hearing loss for speech in noise of 3 db is more disturbing than a hearing loss for speech in quiet of 21 db Plomp & Duquesnoy (1982) The data provide insight into the most appropriate amplification strategy Directional microphones, FM systems Counseling, realistic expectations

8 SNR Hearing Loss Killion, Seminars in Hearing, 2002 by the time background talk reaches a level where it is just mildly disruptive to intelligibility for normal hearers it can become a serious masker for the sensorineural (Groen, 1969, pg 279)

9 Motivation to develop a new test Carhart & Tillman (1970) urged the development of a quick clinical speech-innoise test Sentence tests were developed but limited uptake by clinicians SSI Speaks & Jerger,1965 SPIN Kalikow, Stevens, & Elliot, 1977 CST Cox, Alexander, and Gilmore, 1987 SIN Killion and Villchur, 1993 HINT Nilsson, Soli, and Sullivan, 1994

10 Words or Sentences? Advantages of sentences More realistic - fluent speech High face validity Short test administration time Advantages of monosyllables Minimize the effects of working memory and linguistic context on performance Most popular stimulus type among audiologists Disadvantages of sentences Additional cognitive demands Context influences performance making it difficult to determine basic auditory function Disadvantages of monosyllables Less realistic Lack co-articulation and prosody cues

11 Creation of the WIN Goal was to develop a clinically viable instrument using monosyllabic words that would quickly quantify hearing loss for speech in terms of signal-to-noise ratio (S/N, SNR)

12 Speech NU No. 6 monosyllabic materials recorded by a female speaker (Veterans Affairs Speech Recognition and Identification Materials, Disc 1.1, 1991) widespread clinical use familiar to audiologists enabled word-recognition data to be obtained in quiet and in the background noise using the same speaker, speaking the same words.

13 PERCENT CORRECT RECOGNITION 100 NU No SAME SPEAKER Tillman & Carhart, 1966 Wilson et al., 1976 Wilson et al., NU No DIFFERENT SPEAKERS Tillman & Carhart, 1966 Rintelmann et al., 1974 Wilson et al., 1976 Wilson et al., PRESENTATION LEVEL (db SPL)

14 PERCENT CORRECT RECOGNITION PRESENTATION LEVEL (db HL)--WIN S S SIGNAL-TO-NOISE RATIO (db)

15 Noise Multitalker babble recorded by Causey (1988) and consists of three female and three male speakers talking about various topics (Sperry, et al 1997). most common environmental noise encountered by listeners in everyday life (Plomp, 1978). difficult listening environment because the spectrum is speech shaped and there is minimal amplitude modulation of the envelope

16 CORRECT RECOGNITION (%) Does the type of noise matter? 100 NORMAL HEARING MTB SSN HEARING LOSS Wilson & Cates, PRESENTATION LEVEL (db S/N)

17 Wilson, Journal of the American Academy of Audiology, 2003 Wilson & McArdle, Journal of the American Academy of Audiology, 2007 WIN Example Say the word voice Quiet Noise (12 db S/N)

18 Descending Paradigm Materials are recorded at multiple signalto-noise ratios that are presented in a descending manner

19 Speech -to-noise Ratios To mimic the real world in which background noises are maintained at fairly constant levels for given listening situations, the level of the multitalker babble was fixed relative to the level of the speech signal which was varied

20 Descending Paradigm Materials are recorded at multiple signalto-noise ratios that are presented in a descending manner Decrement in db S/N was fixed Scored in terms of SNR 50% point derived with the Spearman- Kärber equation (Finney, 1952) Allows for stopping rule

21 PERCENT CORRECT RECOGNITION PRESENTATION LEVEL (db HL)--WIN S S SIGNAL-TO-NOISE RATIO (db) Wilson & Cates, Journal of the American Academy of Audiology, 2008

22 PERCENT CORRECT WORD RECOGNITION Final version - WIN Ten NU No.6 words per SNR Descending paradigm Seven SNR levels (24 to 0 db) in 4 db decrements Test time 5 min SIGNAL-TO-BABBLE RATIO (db) NORMAL HEARING HEARING LOSS 0 Wilson, PRESENTATION LEVEL (db SPL)

23 50% POINT (db S/B)--LIST 2 Half lists 35 words 24 (99) (258) (216) % POINT (db S/B)--LIST 1 Wilson & Burks, 2005

24 Test Administration List 1, Random 2 24-dB S/B 12-dB S/B 0-dB S/B 20-dB S/B 16-dB S/B 1 FOOD 16 RUSH 31 BATH 2 PAIN 17 VOICE 32 DAB 3 LATE 18 TOOL 33 GET 4 DODGE 19 SEARCH x 34 READ 5 COOL 20 GOOD 35 LIFE 8-dB S/B 6 DITCH 21 MAKE # Correct 7 KICK 22 SOAP 8 LUCK 23 YOUNG 9 GUN 24 SOUR 10 SUCH 25 HALF 4-dB S/B 11 WIRE 26 SHEEP 12 TIME 27 MESS 13 HAVE x 28 MOOD 14 JUDGE 29 LONG 15 DOG 30 FAR x x xx x 17

25 Spearman-Kärber Equation (Finney, 1952) 50% = i + ½(d) (d)(# correct)/(w) i = the initial presentation level (db S/B) d = the attenuation step size (decrement) w = the number of items per decrement.

26 WIN Example: Initial starting level 24 db S/N, 4 db step size, 5 words per decrement, # correct = 17 50% = 24 + ½(4) (4)(17)/5 50% = (0.8)* 50% = = 12.4 db S/N *The "0.8" is the attenuation step size (4 db) divided by the number of words per step (5)

27 # Correct Threshold Name SS# Age Date By Ear Level Track 25, List 1, Random 1 24-dB S/B 12-dB S/B 0-dB S/B 1 pain 16 hate 31 gaze 2 youth 17 shack 32 life 3 wheat 18 tool 33 get 4 dodge 19 voice 34 read 5 cool 20 rush 35 bath 20-dB S/B 8-dB S/B 6 ditch 21 turn # Correct 7 ring 22 young Threshold (50%) db S/B 8 kick 23 bite 9 chair 24 pick 10 luck 25 half 16-dB S/B 4-dB S/B 11 base 26 far 12 wire 27 learn 13 red 28 mood 14 time 29 talk 15 judge 30 note Ear Level Track 26, List 2, Random 1 24-dB S/B 12-dB S/B 0-dB S/B 1 food 16 good 31 back 2 road 17 search 32 dab 3 juice 18 pass 33 kill 4 late 19 witch 34 nice 5 hire 20 chief 35 calm 20-dB S/B 8-dB S/B 6 tire 21 sour # Correct 7 such 22 doll Threshold (50%) db S/B 8 shawl 23 deep 9 haze 24 soap 10 gun 25 make 16-dB S/B 4-dB S/B 11 live 26 beg 12 date 27 mess 13 gas 28 long 14 have 29 mouse 15 dog 30 sheep PROFOUND SEVERE MODERATE MILD NORMAL

28 24 20 LIST 1 Test - Retest Data % POINT (db S/B)--RETEST LIST % POINT (db S/B)--TEST Wilson & Burks, 2005

29 PERCENT CORRECT RECOGNITION Normal Hearing Hearing Loss Monaural Binaural Monaural Binaural Level MeanSD Mean(SD) Mean(SD) Mean(SD) 70-dB SPL 3.6 (1.3) 2.9 (1.1) 12.6 (3.3) 11.3 (4.0) 90-dB SPL 4.8 (1.9) 3.7 (1.3) 12.5 (2.9) 11.3 (3.0) dB SPL NORMAL HEARING LOSS Monaural vs Monaural Binaural Binaural dB SPL binaural 1 db better than monaural SIGNAL-TO-BABBLE RATIO (db) Wilson, 2003

30 % CORRECT RECOGNITION at 80-dB HL (26.9%) 176 (45.5%) 107 (27.6%) Relationship between recognition performance in quiet and noise % CORRECT POINT (db S/B) Wilson & McArdle, Journal of Rehabilitation Research and Development, 2005

31 PURE-TONE AVERAGE (db HL) , 1000, 2000 Hz r = , 2000, 4000 Hz Relationship between speech-innoise performance and PTA r = % Point WORDS-IN-NOISE (db S/B) N = 315

32 50% Point WIN (db S/B) Wilson & McArdle, Journal of Rehabilitation Research and Development, (29--40%) 12 (43--60%) % Point QuickSIN (db S/B)

33 % CORRECT RECOGNITION at 104-dB SPL Wilson, McArdle, & Smith, Journal of Speech, Language, Hearing Research, BKB-SIN HINT % 78% 28% 72% QuickSIN WIN % 90% 1% 99% % CORRECT POINT (db S/B)

34 PERCENT CORRECT--SPRINT Wilson & Cates, Journal of the American Academy of Audiology, R= r = % POINT (db S/N)--WIN

35 what about children Performances by children (6-12 yr) are poorer than performances by adults on recognition and identification tasks in quiet. When the listening task is degraded (e.g., background noise), performance differences observed in quiet between children and young adult listeners become exaggerated. (Goldman et al., 1970; Palva and Jokinen, 1975; Elliott et al., 1979; Stuart et al., 2006)

36 Kid WIN 6 12 years old 42 kids per year Standard WIN test used with adults

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38 Kids vs Adults

39 To purchase the WIN The WIN on CD is available through the ETSU Foundation Contact:

40 Acknowledgments Richard Wilson, PhD James H. Quillen VA, Mountain Home, TN Sherri Smith, AuD/PhD Bay Pines Auditory Research Lab Contributors Mitzarie Carlo, AuD/PhD Monica Mejia, AuD Jana Wells, AuD Elizabeth Townsend, AuD Cassie Eiffert, AuD Liz Talmage, AuD Vicky Williams, BA Lynette Dornton, BS

41 Spanish-English Bilingual Speech Perception in Noise Mitzarie A. Carlo, Au.D., Ph.D. University of Puerto Rico Medical Sciences Campus

42 Speech-in-Noise Testing What we know: It s a very important part of an audiological evaluation. Should test for speech recognition in noise. There are plenty of commercially available speech in noise tests in the U.S. The Words-in-Noise (WIN; Wilson, 2003) test is simple to administer and is a valid and reliable test of speech recognition in noise.

43 Spanish-English Bilinguals in Audiology What we know: Clinics The Hispanic population in the U.S. is growing very quickly and steadily. According to the U.S. Census Bureu (1996), by the year 2050, Hispanics are expected to account for 1/4 th of the U.S. population. A growing number of Hispanic patients are visiting Audiology clinics. Many Hispanics in the U.S. speak fluent English.

44 Spanish Speech-in-Noise Testing What we know: The HINT is the only speech recognition in noise test commercially available in Spanish (S-HINT; Soli, Vermiglio, Wen, & Filesari, 2002). Sentences

45 What should we do with Spanish-English bilinguals and speech-in-noise testing? Test them using the S-HINT? Skip speech-in-noise testing for bilinguals? Test them using an English speech-in-noise measure? Hmmm. tempting! They speak English, why not? Let s check the literature first.

46 Bilingual Speech Recognition What does being bilingual really mean? Knowledge of a language vs. fluency of a language Age of acquisition Immersion in the language Use of each language Amount of use Context of use

47 Evidence for Across-Language Lexical Competition Parallel lexical activation during eye tracking task (Spivey & Marian, 1999; Marian & Spivey, 2003) Competition from phonologically-similar words in phoneme monitoring task (Colomé, 2001). Cross-language interference in Stroop task (Preston & Lambert, 1969)

48 Models of Bilingual Speech Recognition Spoken words from either language will activate word candidates in both lexicons. The individual can suppress words from the nontarget language (Green, 1998). The target language is receiving more activation and therefore it is easier to retrieve words from that language (Dijkstra & van Heuven, 2002). The context, environment, and intention to use a language will make it more accessible for recognition (Grosjean, 1997).

49 Performance of Bilinguals on Speech Recognition Tests in Quiet Bilinguals tested in their second language have equivalent speech recognition in quiet performance to that of monolinguals of that language. Consonant recognition (Takata & Nábělek, 1990) W-22 words (Rogers, Lister, Febo, Bessing, & Abrams, 2006) SPIN sentences (Mayo, Florentine, & Buus, 1997) HINT sentences (von Hapsburg, Champlin, & Shetty, 2004)

50 Performance of Bilinguals on Speech Recognition Tests in Noise Bilinguals tested in their second language have poorer speech recognition in noise performance than monolinguals of that language. Consonant recognition (Takata & Nábělek, 1990) W-22 words (Rogers, Lister, Febo, Bessing, & Abrams, 2006) WIN words (Wilson, 2003) SPIN sentences (Mayo, Florentine, & Buus, 1997) HINT sentences (von Hapsburg, Champlin, & Shetty, 2004)

51 Effects of Age of Acquisition of the Second Language on Speech-in-Noise Performance Bilinguals that learned the second language before the age of 6 years have better speechin-noise performance in their second language than those who learned it later in life. Mayo et al. (1997) Carlo (2008)

52 Conclusion About Speech Recognition Testing in Bilinguals? In quiet We can test them in either language In noise We must test them in their first language

53 Spanish Words-in-Noise Test S-WIN

54 Words 100 words from the Spanish Picture Identification Task (SPIT; McCullough & Wilson, 2001) Bisyllables Diga usted

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56 Spanish Multitalker Babble 6 Spanish speakers Three two-minute continuous speech samples each Broadcasting studio Each of the 18 samples was adjusted to the mean rms of the samples.

57 Spanish Multitalker Babble First speech samples of each of the speakers were combined together to create the multitalker babble. Same for the second and third samples Each of the three 2-min multitalker babble was separated into 21, 5.7sec segments. The 50 segments with the most homogeneous rms values were selected for the study.

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59 Test Files Babble fixed at 70-dB SPL Words adjusted to accommodate: -4, 0, 4, 8, 12, and 16 db S/N A different randomization of the 100 words for each of the six signal-to-noise ratio conditions. Each list was split into four 25-word lists.

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61 Step 1: Method 6 Spanish-speaking participants Ages yrs Normal hearing All reported using Spanish at least 50% of the time Four 25-word lists were presented at each of the signal-to-noise ratios. Two 30-minute sessions

62 Step 1: Results Mean 50% point: -37-dB S/N Spearman-Kärber equation (Finney, 1952) Individual Data Mean Data

63 Step 2: Hearing Impaired 20 male veterans with SNHL Ages yrs (mean age of 74 yrs) Monolingual Spanish speakers Hz Mean SD

64 Step 2: Hearing Impaired S/N condition of -4-dB was eliminated. 7 words were completely eliminated from the test. S/N conditions of 16 and 20-dB were added. Babble fixed at 70-dB SPL. Based on Study 1, 11 of the 100 words were selected for the 0, 4, and 8-dB S/N conditions. Remaining 60 words were presented at each: 12, 16, and 20-dB S/N conditions.

65 Step 2: Results Mean data for HI participants dB 4dB 8dB 12dB 16dB 20dB

66 Step 3: Normal Hearing 20 monolingual Spanish participants Ages yrs (mean 24 yrs) Normal hearing 20 Spanish-English bilingual participants Ages yrs (mean 25 yrs) Fluent in both languages Added 24-dB S/N condition to the test. Two lists of 25 words 24, 20, 16, 12, 8, 4, and 0-dB S/N conditions Babble fixed at 70-dB SPL

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68 Recognition Performance Recognition Performance Study 3: Results Bilinguals mean 50%: 6.1-dB S/N (SD: 1.4) Polynomial Regression: Performance of Bilingual Listeners on the S-WIN Polynomial Regressions: Performance of Monolingual Spanish Listeners on the S-WIN Monolinguals mean 50%: 6.4-dB S/N (SD: 0.9) 100% 100% 90% 80% 80% 70% 60% 60% 50% 40% 40% 30% 20% 20% 10% 0% Listening Condition (db SNR) 0% Listening Condition (db SNR)

69 Study 3: Results No statistical difference (p >.05) in performance between monolinguals and bilinguals. Mean data for both groups: 6.25-dB S/N

70 Step 4: Hearing Impaired I 15 non-veterans with SNHL Ages yrs (mean 62 yrs) Two, 25-word lists of the S-WIN 0 to 24-dB S/N Babble fixed at 70-dB SPL Hz Mean SD

71 Step 4: Results HI HI by list Mean 50%: 9.41-dB S/N (1.61) List 1 List 2 both lists dB 4dB 8dB 12dB 16dB 20dB 24dB

72 Step 5: Hearing Impaired II 27 veterans with SNHL Ages yrs (mean 74 yrs) Two, 25-word lists of the S-WIN 0 to 24-dB S/N Babble fixed at 70-dB SPL Hz Mean SD

73 Step 5: Results HI 100 Mean 50%: 14.4-dB S/N (2.8 db) dB 4dB 8dB 12dB 16dB 20dB 24dB

74 Data Summary Percent correct for 3 groups of listeners on the S-WIN Normal Hearing Hearing Impaired I Hearing Impaired II dB 4dB 8dB 12dB 16dB 20dB 24dB

75 Data Summary S-WIN Mean 50% point (db S/N) SD (db) Normal Hearing Hearing Impaired I Hearing Impaired II WIN Mean 50% point (db S/N) SD (db) Normal Hearing 3.6*, 3.9** 1.3*, 1** Hearing Impaired I equivalent 10.2* 3.6* Hearing Impaired II equivalent 14** 3.25** * Wilson (2003) ** Wilson, McArdle, & Smith (2007)

76 References Carlo, M. (2008). Effects of bilingualism on speech recognition performance in noise. Unpublished doctoral dissertation. University of South Florida, Tampa. Colomé, A. (2001). Lexical activation in bilinguals' speech production: Language-specific or language-independent? Journal of Memory and Language, 45, Dijkstra, T., & Van Heuven, W. J. B. (2002). The architecture of the bilingual word recognition system: From identification to decision. Bilingualism: Language and Cognition, 5, Finney, D. J. (1952). Statistical Method in Biological Essay. London: C. Griffen. Green, D.W. (1998). Mental control of the bilingual lexico-semantic system. Bilingualism: Language and Cognition, 1, Grosjean, F. (1997). Processing mixed language: Issues, findings and models. In A. M. B. De Groot, & J. F. Kroll (Eds.), Tutorials in bilingualism: Psycholinguistic perspectives (pp ). Mahwah, NJ: LEA.

77 Marian, V., & Spivey, M. (2003). Bilingual and monolingual processing of competing lexical items. Applied Psycholinguistics, 24, Mayo, L., Florentine, M., & Buus, S. (1997). Age of second-language acquisition and perception of speech in noise. Journal of Speech, Language, and Hearing Research, 40, McCullough, J. A., & Wilson, R. H. (2001). Performance on a Spanish picture identification task using a multimedia format. Journal of the American Academy of Audiology, 12, Preston, M. S., & Lambert, W. E. (1969). Interlingual interference in a bilingual version of the Stroop color-word task. Journal of Verbal Learning and Verbal Behavior, 8, Rogers, C. L., Lister, J. L., Febo, D. M., Bessing, J. M., & Abrams, H. B. (2006). Effects of bilingualism, noise, and reverberation on speech perception by listeners with normal hearing. Applied Psycholinguistics, 27, Soli, S. D., Vermiglio, A., Wen, K., & Filesari, C. A. (2002). Development of the Hearing In Noise Test in Spanish. Journal of the Acoustical Society of America, 112, 2384.

78 Spivey, M. J., & Marian, V. (1999). Cross talk between native and second languages: Partial activation of an irrelevant lexicon. Psychological Science, 10, Takata, Y., & Nábělek, A. K. (1990). English consonant recognition in noise and in reverberation by Japanese and American listeners. Journal of the Acoustical Society of America, 88, von Hapsburg, D., Champlin, A., & Shetty, S.R. (2004). Reception thresholds for sentences in bilingual (Spanish/English) and monolingual (English) listeners. Journal of the American Academy of Audiology, 15, Wilson, R. (2003). Development of a speech-in-multitalker-babble paradigm to assess word-recognition performance. Journal of the American Academy of Audiology, 14, Wilson, R. H., McArdle, R. A., & Smith, S. L. (2007). An evaluation of the BKB-SIN, HINT, QuickSIN, and WIN materials on listeners with normal hearing and listeners with hearing loss. Journal of Speech, Language, and Hearing Research, 50,

79 Questions???

80 REFERENCES Carhart R. Basic principles of speech audiometry. Acta Otolaryngol. 1951;40: Cord, Walden, Atack (1992) Unpublished paper. Walter Reed Army Medical Hospital. BKB-SIN Speech-in-Noise Test [compact disk]. Elk Grove Village (IL): Etymotic Research, Inc.; Dubno JR, Horwitz AR, Ahistrom JB. (2002) Benefit of modulated maskers for speech recognition by younger and older adults with normal hearing. J Acoust Soc Am 111: Dubno JR, Horwitz AR, Ahistrom JB. (2003) Recovery from prior stimulation: Masking of speech by interrupted noise for younger and older adults with normal hearing. J Acoust Soc Am 113: Festen JM, Plomp R. (1990) Effects of fluctuating noise and interfering speech on the speech-reception threshold for impaired and normal hearing. J Acoust Soc Am 88: Kalikow DN, Stevens KN, Elliott LL. Development of a test of speech intelligibility in noise using sentence materials with controlled word predictability. J Acoust Soc Am. 1977;61: Killion MC. New thinking on hearing in noise: a generalized articulation index. Sem Hear. 2002;23: Killion MC, Niquette PA, Gudmundsen GI, Revit LJ, Banerjee S. Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normalhearing and hearing-impaired listeners. J Acoust Soc Am. 2004;116(4 Pt 1):

81 Kryter KD. Effects of ear protective devices on the intelligibility of speech in noise. J Acoust Soc Am. 1946;18(2): McArdle RA, Wilson RH, Burks CA. Speech recognition in multitalker babble using digits, words, and sentences. J Am Acad Audiol. 2005;16: McArdle, R., & Wilson, R.H. (2006). Homogeneity of the 18 QuickSIN Lists. Journal of the American Academy of Audiology, 17(3), Middelweerd MJ, Festen JM, Plomp R. (1990) Difficulties with speech intelligibility in noise in spite of a normal pure-tone audiogram. Audiol 29:1-7. Miller GA, Heise GA, Lichten W. The intelligibility of speech as a function of the context of the test materials. J Exp Psychol. 1951;41(5): Nilsson M, Soli SD, Sullivan JA. Development of the Hearing in Noise Test for the measurement of speech reception thresholds in quiet and in noise. J Acoust Soc Am. 1994(2);95: Plomp R. Auditory handicap of hearing impairment and the limited benefit of hearing aids. J Acoust Soc Am. 1978;63(2): Pollack I, Pickett JM. Masking of speech by noise at high sound levels. J Acoust Soc Am. 1958;30(2): Shanks JE, Wilson RH, Larson V, Williams D. Speech recognition performance of patients with sensorineural hearing loss under unaided and aided conditions using linear and compression hearing aids. Ear Hear. 2002;23(4): Soli, S. D., Vermiglio, A., Wen, K., & Filesari, C. A. (2002). Development of the Hearing In Noise Test in Spanish. Journal of the Acoustical Society of America, 112, Stephens SDG. The input for a damaged cochlea: a brief review. Brit J Audiol. 1976;10: Wilson RH. J Rehab Res & Dev Strom KE. The HR 2003 dispenser survey. Hear Rev. 2003;10(6): Wilson RH. Development of a speech-in-multitalker-babble paradigm to assess wordrecognition performance. J Am Acad Audiol. 2003;14(9):

82 Takahashi GA, Bacon SP. (1992) Modulation detection, modulation masking, and speech understanding in noise in the elderly. J Speech Hear Res 35: Wilson, R. H., and Carhart, R. (1969) Influence of pulsed masking on the threshold for spondees. J Acoust Soc Am 46: Wilson RH, Burks CA, Weakley DG. Word recognition of digit triplets and monosyllabic words in multitalker babble by listeners with sensorineural hearing loss. J Am Acad Audiol : Wilson RH, McArdle RA. Speech signals used to evaluate functional status of the auditory system. J Rehab Res & Dev. 2005;42(Suppl 2): Wilson RH, Weakley DG. The 500 Hz masking-level difference and word recognition in multitalker babble for 40- to 89-year-old listeners with symmetrical sensorineural hearing loss. J Am Acad Audiol. 2005;16(6): Wilson RH, Weakley DG. The use of digit triplets to evaluate word-recognition abilities in multitalker babble. Seminars in Hearing. 2004;25(1):93-111