scholarly journals Psychometric Characteristics of Spanish Monosyllabic, Bisyllabic, and Trisyllabic Words for Use in Word-Recognition Protocols

2020 ◽  
Vol 31 (07) ◽  
pp. 531-546
Author(s):  
Mitzarie A. Carlo ◽  
Richard H. Wilson ◽  
Albert Villanueva-Reyes
Keyword(s):  
Word Recognition ◽  
Recognition Performance ◽  
Normal Hearing ◽  
Current Data ◽  
Hearing Level ◽  
Psychometric Characteristics ◽  
Plural Form ◽  
Individual Word ◽  
The Mean ◽  
The Individual

Abstract Background English materials for speech audiometry are well established. In Spanish, speech-recognition materials are not standardized with monosyllables, bisyllables, and trisyllables used in word-recognition protocols. Purpose This study aimed to establish the psychometric characteristics of common Spanish monosyllabic, bisyllabic, and trisyllabic words for potential use in word-recognition procedures. Research Design Prospective descriptive study. Study Sample Eighteen adult Puerto Ricans (M = 25.6 years) with normal hearing [M = 7.8-dB hearing level (HL) pure-tone average] were recruited for two experiments. Data Collection and Analyses A digital recording of 575 Spanish words was created (139 monosyllables, 359 bisyllables, and 77 trisyllables), incorporating materials from a variety of Spanish word-recognition lists. Experiment 1 (n = 6) used 25 randomly selected words from each of the three syllabic categories to estimate the presentation level ranges needed to obtain recognition performances over the 10 to 90% range. In Experiment 2 (n = 12) the 575 words were presented over five 1-hour sessions using presentation levels from 0- to 30-dB HL in 5-dB steps (monosyllables), 0- to 25-dB HL in 5-dB steps (bisyllables), and −3- to 17-dB HL in 4-dB steps (trisyllables). The presentation order of both the words and the presentation levels were randomized for each listener. The functions for each listener and each word were fit with polynomial equations from which the 50% points and slopes at the 50% point were calculated. Results The mean 50% points and slopes at 50% were 8.9-dB HL, 4.0%/dB (monosyllables), 6.9-dB HL, 5.1%/dB (bisyllables), and 1.4-dB HL, 6.3%/dB (trisyllables). The Kruskal–Wallis test with Mann–Whitney U post-hoc analysis indicated that the mean 50% points and slopes at the 50% points of the individual word functions were significantly different among the syllabic categories. Although significant differences were observed among the syllabic categories, substantial overlap was noted in the individual word functions, indicating that the psychometric characteristics of the words were not dictated exclusively by the syllabic number. Influences associated with word difficulty, word familiarity, singular and plural form words, phonetic stress patterns, and gender word patterns also were evaluated. Conclusion The main finding was the direct relation between the number of syllables in a word and word-recognition performance. In general, words with more syllables were more easily recognized; there were, however, exceptions. The current data from young adults with normal hearing established the psychometric characteristics of the 575 Spanish words on which the formulation of word lists for both threshold and suprathreshold measures of word-recognition abilities in quiet and in noise and other word-recognition protocols can be based.

scholarly journals Effects of the Carrier Phrase on Word Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Vol 31 (06) ◽  
pp. 412-441 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Abstract Background In the 1950s, with monitored live voice testing, the vu meter time constant and the short durations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrier phrase amplitude to monitor (indirectly) the presentation level of the words. This practice continues with recorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrase has on word recognition performance needs clarification, which is the topic of this study. Purpose Recordings of Northwestern University Auditory Test No. 6 by two female speakers were used to compare word recognition performances with and without the carrier phrases when the carrier phrase and test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1 speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in the target word with the largest root mean square amplitude was used to equate the target word amplitudes. Research Design A quasi-experimental, repeated measures design was used. Study Sample Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average [PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participated in two, one-hour sessions. Data Collection and Analyses Each listener had 16 listening conditions (2 speakers × 2 carrier phrase conditions × 4 presentation levels) with 100 randomized words, 50 different words by each speaker. Each word was presented 8 times (2 carrier phrase conditions × 4 presentation levels [YNH, 0- to 24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8, 25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated between speakers and randomized by blocks of the four conditions. Central tendency and repeated measures analyses of variance statistics were used. Results With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3% (OHL) significantly better with the carrier phrase than without the carrier phrase. These differences were in part attributed to the distortion of some words caused by the excision of the words from the carrier phrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditions by both listener groups were not significantly different, except for one condition (YNH listeners at 8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) than for the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for the VA-2 speaker. Although the mean results were clear, the variability in performance differences between the two carrier phrase conditions for the individual participants and for the individual words was striking and was considered in detail. Conclusion The current data indicate that word recognition performances with and without the carrier phrase (1) were different when the carrier phrase and target word were produced in the same utterance with poorer performances when the target words were excised from their respective carrier phrases (VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independent utterances (VA-2 speaker).

A Comparison of Recognition Performances in Speech-Spectrum Noise by Listeners with Normal Hearing on PB-50, CID W-22, NU–6, W-1 Spondaic Words, and Monosyllabic Digits Spoken by the Same Speaker

2008 ◽  
Vol 19 (06) ◽  
pp. 496-506 ◽  
Author(s):  
Richard H. Wilson ◽  
Rachel McArdle ◽  
Heidi Roberts
Keyword(s):  
Word Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Normal Hearing ◽  
Psychometric Characteristics ◽  
Monosyllabic Word ◽  
Repeated Measures Design ◽  
Word Lists ◽  
Monosyllabic Words ◽  
Speech Spectrum

Background: So that portions of the classic Miller, Heise, and Lichten (1951) study could be replicated, new recorded versions of the words and digits were made because none of the three common monosyllabic word lists (PAL PB-50, CID W-22, and NU–6) contained the 9 monosyllabic digits (1–10, excluding 7) that were used by Miller et al. It is well established that different psychometric characteristics have been observed for different lists and even for the same materials spoken by different speakers. The decision was made to record four lists of each of the three monosyllabic word sets, the monosyllabic digits not included in the three sets of word lists, and the CID W-1 spondaic words. A professional female speaker with a General American dialect recorded the materials during four recording sessions within a 2-week interval. The recording order of the 582 words was random. Purpose: To determine—on listeners with normal hearing—the psychometric properties of the five speech materials presented in speech-spectrum noise. Research Design: A quasi-experimental, repeated-measures design was used. Study Sample: Twenty-four young adult listeners (M = 23 years) with normal pure-tone thresholds (≤20-dB HL at 250 to 8000 Hz) participated. The participants were university students who were unfamiliar with the test materials. Data Collection and Analysis: The 582 words were presented at four signal-to-noise ratios (SNRs; −7-, −2-, 3-, and 8-dB) in speech-spectrum noise fixed at 72-dB SPL. Although the main metric of interest was the 50% point on the function for each word established with the Spearman-Kärber equation (Finney, 1952), the percentage correct on each word at each SNR was evaluated. The psychometric characteristics of the PB-50, CID W-22, and NU–6 monosyllabic word lists were compared with one another, with the CID W-1 spondaic words, and with the 9 monosyllabic digits. Results: Recognition performance on the four lists within each of the three monosyllabic word materials were equivalent, ±0.4 dB. Likewise, word-recognition performance on the PB-50, W-22, and NU–6 word lists were equivalent, ±0.2 dB. The mean recognition performance at the 50% point with the 36 W-1 spondaic words was ˜6.2 dB lower than the 50% point with the monosyllabic words. Recognition performance on the monosyllabic digits was 1–2 dB better than mean performance on the monosyllabic words. Conclusions: Word-recognition performances on the three sets of materials (PB-50, CID W-22, and NU–6) were equivalent, as were the performances on the four lists that make up each of the three materials. Phonetic/phonemic balance does not appear to be an important consideration in the compilation of word-recognition lists used to evaluate the ability of listeners to understand speech.A companion paper examines the acoustic, phonetic/phonological, and lexical variables that may predict the relative ease or difficulty for which these monosyllable words were recognized in noise (McArdle and Wilson, this issue).

Development of a Speech-in-Multitalker-Babble Paradigm to Assess Word-Recognition Performance

2003 ◽  
Vol 14 (09) ◽  
pp. 453-470 ◽  
Author(s):  
Richard H. Wilson
Keyword(s):  
Hearing Loss ◽  
Word Recognition ◽  
Recognition Performance ◽  
Recognition Task ◽  
Normal Hearing ◽  
Presentation Level ◽  
The Individual ◽  
Binaural Listening

A simple word-recognition task in multitalker babble for clinic use was developed in the course of four experiments involving listeners with normal hearing and listeners with hearing loss. In Experiments 1 and 2, psychometric functions for the individual NU No. 6 words from Lists 2, 3, and 4 were obtained with each word in a unique segment of multitalker babble. The test paradigm that emerged involved ten words at each of seven signal-to-babble ratios (S/B) from 0 to 24 dB. Experiment 3 examined the effect that babble presentation level (70, 80, and 90 dB SPL) had on recognition performance in babble, whereas Experiment 4 studied the effect that monaural and binaural listening had on recognition performance. For listeners with normal hearing, the 90th percentile was 6 dB S/B. In comparison to the listeners with normal hearing, the 50% correct points on the functions for listeners with hearing loss were at 5 to 15 dB higher signal-to-babble ratios.

Effects of the Carrier Phrase on Word-Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Background: In the 1950s, with monitored live voice testing, the vu meter time constant and the shortdurations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrierphrase amplitude tomonitor (indirectly) the presentation level of the words. This practice continues withrecorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrasehas on word recognition performance needs clarification, which is the topic of this study.<br />Purpose: Recordings of Northwestern University Auditory Test No. 6 by two female speakers were usedto compare word recognition performances with and without the carrier phrases when the carrier phraseand test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in thetarget word with the largest root mean square amplitude was used to equate the target word amplitudes.<br />Research Design: A quasi-experimental, repeated measures design was used.<br />Study Sample: Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average[PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participatedin two, one-hour sessions.<br />Data Collection and Analyses: Each listener had 16 listening conditions (2 speakers 3 2 carrier phraseconditions 3 4 presentation levels) with 100 randomized words, 50 different words by each speaker.Each word was presented 8 times (2 carrier phrase conditions 3 4 presentation levels [YNH, 0- to24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8,25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated betweenspeakers and randomized by blocks of the four conditions. Central tendency and repeated measuresanalyses of variance statistics were used.<br />Results: With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3%(OHL) significantly better with the carrier phrase than without the carrier phrase. These differences werein part attributed to the distortion of some words caused by the excision of the words from the carrierphrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditionsby both listener groups were not significantly different, except for one condition (YNH listeners at8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) thanfor the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for theVA-2 speaker. Although the mean results were clear, the variability in performance differences betweenthe two carrier phrase conditions for the individual participants and for the individual words was strikingand was considered in detail.<br />Conclusion: The current data indicate that word recognition performances with and without the carrierphrase (1) were different when the carrier phrase and target word were produced in the same utterancewith poorer performances when the target words were excised from their respective carrier phrases(VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independentutterances (VA-2 speaker).<br />See the Supplementary Data tab for supplementary materials.

Amplitude (vu and rms) and Temporal (msec) Measures of Two Northwestern University Auditory Test No. 6 Recordings

2015 ◽  
Vol 26 (04) ◽  
pp. 346-354 ◽  
Author(s):  
Richard H. Wilson
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Recognition Performance ◽  
Cooperative Effort ◽  
Northwestern University ◽  
Male Speaker ◽  
The Mean ◽  
Standard Deviations ◽  
The Individual ◽  
Target Words

Background: In 1940, a cooperative effort by the radio networks and Bell Telephone produced the volume unit (vu) meter that has been the mainstay instrument for monitoring the level of speech signals in commercial broadcasting and research laboratories. With the use of computers, today the amplitude of signals can be quantified easily using the root mean square (rms) algorithm. Researchers had previously reported that amplitude estimates of sentences and running speech were 4.8 dB higher when measured with a vu meter than when calculated with rms. This study addresses the vu–rms relation as applied to the carrier phrase and target word paradigm used to assess word-recognition abilities, the premise being that by definition the word-recognition paradigm is a special and different case from that described previously. Purpose: The purpose was to evaluate the vu and rms amplitude relations for the carrier phrases and target words commonly used to assess word-recognition abilities. In addition, the relations with the target words between rms level and recognition performance were examined. Research Design: Descriptive and correlational. Study Sample: Two recoded versions of the Northwestern University Auditory Test No. 6 were evaluated, the Auditec of St. Louis (Auditec) male speaker and the Department of Veterans Affairs (VA) female speaker. Data Collection and Analysis: Using both visual and auditory cues from a waveform editor, the temporal onsets and offsets were defined for each carrier phrase and each target word. The rms amplitudes for those segments then were computed and expressed in decibels with reference to the maximum digitization range. The data were maintained for each of the four Northwestern University Auditory Test No. 6 word lists. Descriptive analyses were used with linear regressions used to evaluate the reliability of the measurement technique and the relation between the rms levels of the target words and recognition performances. Results: Although there was a 1.3 dB difference between the calibration tones, the mean levels of the carrier phrases for the two recordings were −14.8 dB (Auditec) and −14.1 dB (VA) with standard deviations <1 dB. For the target words, the mean amplitudes were −19.9 dB (Auditec) and −18.3 dB (VA) with standard deviations ranging from 1.3 to 2.4 dB. The mean durations for the carrier phrases of both recordings were 593–594 msec, with the mean durations of the target words a little different, 509 msec (Auditec) and 528 msec (VA). Random relations were observed between the recognition performances and rms levels of the target words. Amplitude and temporal data for the individual words are provided. Conclusions: The rms levels of the carrier phrases closely approximated (±1 dB) the rms levels of the calibration tones, both of which were set to 0 vu (dB). The rms levels of the target words were 5–6 dB below the levels of the carrier phrases and were substantially more variable than the levels of the carrier phrases. The relation between the rms levels of the target words and recognition performances on the words was random.

The Homogeneity with Respect to Intelligibility of Recorded Word-Recognition Materials

2015 ◽  
Vol 26 (04) ◽  
pp. 331-345 ◽  
Author(s):  
Richard H. Wilson ◽  
Rachel McArdle
Keyword(s):  
Hearing Loss ◽  
Word Recognition ◽  
Sensorineural Hearing Loss ◽  
Prospective Studies ◽  
Recognition Performance ◽  
Word List ◽  
Normal Hearing ◽  
Sensorineural Hearing ◽  
Word Lists ◽  
The Mean

Background: In developing the PB-50 word lists, J. P. Egan suggested five developmental principles, two of which were “equal average difficulty” and an “equal range of difficulty” among the lists (page 963). Egan was satisfied that each of the 20 PB-50 lists had equivalent ranges of recognition performances and that the lists produced the same average performances. This was accomplished in preliminary studies that measured the recognition performance of each word and eliminated words that were always or never correct. In preparing for studies of interrupted words, we needed to know the range of difficulty inherent in the speaker specific NU-6 and Maryland CNC materials we planned to use when those words were not interrupted. There were only a few studies in the literature that touched on the range of difficulty characteristic of the word-recognition materials in common usage. The paucity of this information prompted this investigation whose scope broadened to include the CID W-22, Maryland CNC, NU-6, and PB-50 materials spoken by a variety of speakers. Purpose: The purpose was to evaluate the homogeneity with respect to intelligibility of the words that comprise several of the common word-recognition materials used in audiologic evaluations. Research Design: Both retrospective (10) and prospective (3) studies were involved. Data from six of the retrospective studies were from our labs. The prospective studies involved both listeners with normal hearing for pure tones and listeners with sensorineural hearing loss. Study Sample: The sample sizes for the 13 data sets ranged from 24 to 1,030, with 24 the typical number for listeners with normal hearing. Data Collection and Analysis: The retrospective data were from published studies and archived data from our laboratories. The prospective studies involved presentation of the word-recognition materials to the listeners at a comfortable level. An item analysis was conducted on each data set with descriptive statistics used to characterize the data. Additionally, skewness coefficients were calculated on the distributions of word performances and the interquartile range was used to determine minor and major outliers within each set of 200 words and their component 50-word lists (300 words for the Maryland CNCs). Results: For listeners with normal hearing the majority of performances on the words within a 50-word list were better than the mean performance, which produced negatively skewed distributions with outlier performances in every list. For listeners with sensorineural hearing loss the performances on the words within a 50-word list were evenly distributed above and below the mean performance, which yielded essentially normal distributions with few outliers. There were a few words on which performances were better by the listeners with hearing loss. Conclusions: Every list of word-recognition materials has a few words on which recognition performances are noticeably poorer than performances on the majority of the remaining words. If the intention of an experiment is to evaluate performance at the word level, then identifying these “outliers” becomes a necessity. Although not evaluated in this report, the implications for 25-word lists are they should be based on recognition-performance data and not compiled arbitrarily.

Pediatric Arabic Closed-Set Word-Recognition Test: Development and Evaluation of Psychometric Characteristics

2021 ◽  
Vol 32 (08) ◽  
pp. 547-554
Author(s):  
Soha N. Garadat ◽  
Ana'am Alkharabsheh ◽  
Nihad A. Almasri ◽  
Abdulrahman Hagr
Keyword(s):  
Speech Recognition ◽  
Word Recognition ◽  
Hearing Level ◽  
Sigmoid Function ◽  
Psychometric Characteristics ◽  
Monosyllabic Word ◽  
Closed Set ◽  
Significant Difference ◽  
Word Lists ◽  
Arabic Speaking

Abstract Background Speech audiometry materials are widely available in many different languages. However, there are no known standardized materials for the assessment of speech recognition in Arabic-speaking children. Purpose The aim of the study was to develop and validate phonetically balanced and psychometrically equivalent monosyllabic word recognition lists for children through a picture identification task. Research Design A prospective repeated-measure design was used. Monosyllabic words were chosen from children's storybooks and were evaluated for familiarity. The selected words were then divided into four phonetically balanced word lists. The final lists were evaluated for homogeneity and equivalency. Study Sample Ten adults and 32 children with normal hearing sensitivity were recruited. Data Collection and Analyses Lists were presented to adult subjects in 5 dB increment from 0 to 60 dB hearing level. Individual data were then fitted using a sigmoid function from which the 50% threshold, slopes at the 50% points, and slopes at the 20 to 80% points were derived to determine list psychometric properties. Lists were next presented to children in two separate sessions to assess their equivalency, validity, and reliability. Data were subjected to a mixed design analysis of variance. Results No statistically significant difference was found among the word lists. Conclusion This study provided an evidence that the monosyllabic word lists had comparable psychometric characteristics and reliability. This supports that the constructed speech corpus is a valid tool that can be used in assessing speech recognition in Arabic-speaking children.

Standardization of calibration scheme in NB Chirp ABR Hearing Assessment: A Preliminary Study Based on Normal Hearing Soldiers

2021 ◽  
Author(s):  
Zhicheng Li ◽  
Xiaofen Lai ◽  
Jinmei Lai ◽  
Min Qi ◽  
Lianxiong Yuan ◽  
...  
Keyword(s):  
Difference Scheme ◽  
Pure Tone ◽  
Pure Tone Audiometry ◽  
Test Group ◽  
Normal Hearing ◽  
Regression Equation ◽  
Hearing Level ◽  
Model Group ◽  
Threshold Difference ◽  
The Mean

Abstract Background: Optimal medical intervention for veterans suffering from military noise-induced hearing impairment is a major concern of the specialists in military medicine, otology, and audiology sectors. Thus, it is important to objectively and accurately reflect the hearing level of the subject in the intervention to aid hearing and improve the existing hearing disability evaluation program. Purpose: The present study intends to identify the optimal correction scheme by comparing the accuracy and range of deviation of narrow-band chirps evoked auditory brainstem responses (NB Chirp ABR) corrected by different schemes in estimating the hearing level of people with normal hearing. Methods: A total of 66 individuals could hear sounds of a frequency <25dB hearing level (HL) in the pure tone audiometry were randomly divided into a model group (26 subjects), test group 1 (with 20 subjects), and test group 2 (with 20 subjects). The mean threshold difference and the regression equation at each frequency were obtained through the model group, and the correction results of the “mean threshold difference scheme (S1)” and the “regression equation scheme (S2)” were compared in the test groups 1 and 2. All data were analyzed using SPSS 24.0. Results: 1) The accuracy of the estimated hearing level (eHL) of non-corrected NB Chirp ABR was significantly higher than that of NB Chirp ABR corrected by S1 or S2; 2) The range of deviation of the eHL of non-corrected NB Chirp ABR from the pure tone audiometry threshold was greater than that of NB Chirp ABR corrected by S1 or S2 from the pure tone audiometry threshold at 500 and 1000 Hz, while at 2000 and 4000 Hz, the values were similar. Conclusion: Among people with normal hearing, it was necessary to correct NB Chirp ABR at 500 and 1000 Hz for higher accuracy of the eHL, but the strengths of different correction schemes were not defined. For clinical convenience, the “mean threshold difference scheme,” with the correction values of 7 and 4 dB, was recommended for correction. At 2000 and 4000 Hz, it was not necessary to correct NB Chirp ABR. Thus, additional subjects with different HLs should be included in future studies to discuss the differences between the two schemes.

Enhancement of Word-Recognition Performance With a Filtering Technique

1991 ◽  
Vol 34 (6) ◽  
pp. 1436-1438 ◽  
Author(s):  
Richard H. Wilson ◽  
John P. Preece ◽  
Courtney S. Crowther
Keyword(s):  
Word Recognition ◽  
Sound Pressure ◽  
Recognition Performance ◽  
Notch Filter ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Female Speaker ◽  
Sound Pressure Levels ◽  
Filtering Technique ◽  
Notch Filtering

The NU No. 6 materials spoken by a female speaker were passed through a notch filter centered at 247 Hz with a 34-dB depth The filtering reduced the amplitude range within the spectrum of the materials by 10 dB that was reflected as a 7.5-vu reduction measured on a true vu meter. Thus, the notch filtering in effect changed the level calibration of the materials. Psychometric functions of the NU No. 6 materials filtered and unfiltered in 60-dB SPL broadband noise were obtained from 12 listeners with normal hearing. Although the slopes of the functions for the two conditions were the same, the functions were displaced by an average of 5 8 dB with the function for the filtered materials located at the lower sound-pressure levels.

Word-Recognition Performance in Interrupted Noise by Young Listeners with Normal Hearing and Older Listeners with Hearing Loss

2010 ◽  
Vol 21 (02) ◽  
pp. 090-109 ◽  
Author(s):  
Richard H. Wilson ◽  
Rachel McArdle ◽  
Mavie B. Betancourt ◽  
Kaileen Herring ◽  
Teresa Lipton ◽  
...  
Keyword(s):  
Young Adults ◽  
Hearing Loss ◽  
Duty Cycle ◽  
Recognition Performance ◽  
Experimental Studies ◽  
Normal Hearing ◽  
Current Data ◽  
Speech In Noise ◽  
Duty Cycles ◽  
Continuous Noise

Background: The most common complaint of adults with hearing loss is understanding speech in noise. One class of masker that may be particularly useful in the assessment of speech-in-noise abilities is interrupted noise. Interrupted noise usually is a continuous noise that has been multiplied by a square wave that produces alternating intervals of noise and silence. Wilson and Carhart found that spondaic word thresholds for listeners with normal hearing were 28 dB lower in an interrupted noise than in a continuous noise, whereas listeners with hearing loss experienced only an 11 dB difference. Purpose: The purpose of this series of experiments was to determine if a speech-in-interrupted-noise paradigm differentiates better (1) between listeners with normal hearing and listeners with hearing loss and (2) among listeners with hearing loss than do traditional speech-in-continuous-noise tasks. Research Design: Four descriptive/quasi-experimental studies were conducted. Study Sample: Sixty young adults with normal hearing and 144 older adults with pure-tone hearing losses participated. Data Collection and Analysis: A 4.3 sec sample of speech-spectrum noise was constructed digitally to form the 0 interruptions per second (ips; continuous) noise and the 5, 10, and 20 ips noises with 50% duty cycles. The noise samples were mixed digitally with the Northwestern University Auditory Test No. 6 words at selected signal-to-noise ratios and recorded on CD. The materials were presented through an earphone, and the responses were recorded and analyzed at the word level. Similar techniques were used for the stimuli in the remaining experiments. Results: In Experiment 1, using 0 ips as the reference condition, the listeners with normal hearing achieved 34.0, 30.2, and 28.4 dB escape from masking for 5, 10, and 20 ips, respectively. In contrast, the listeners with hearing loss only achieved 2.1 to 2.4 dB escape from masking. Experiment 2 studied the 0 and 5 ips conditions on 72 older listeners with hearing loss, who were on average 13 yr younger and more varied in their hearing loss than the listeners in Experiment 1. The mean escape from masking in Experiment 2 was 7 dB, which is 20–25 dB less than the escape achieved by listeners with normal hearing. Experiment 3 examined the effects that duty cycle (0–100% in 10% steps) had on recognition performance in the 5 and 10 ips conditions. On the 12 young listeners with normal hearing, (1) the 50% correct point increased almost linearly between the 0 and 60% duty cycles (slope = 4.2 dB per 10% increase in duty cycle), (2) the slope of the function was steeper between 60 and 80% duty cycles, and (3) about the same masking was achieved for the 80–100% duty cycles. The data from the listeners with hearing loss were inconclusive. Experiment 4 varied the interburst ratios (0, –6, –12, –24, –48, and –∞ dB) of 5 ips noise and evaluated recognition performance by 24 young adults. The 50% points were described by a linear regression (R 2 = 0.98) with a slope of 0.55 dB/dB. Conclusion: The current data indicate that interrupted noise does provide a better differentiation both between listeners with normal hearing and listeners with hearing loss and among listeners with hearing loss than is provided by continuous noise.

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