Correlating performance on the Listening in Spatialised Noise - Sentences test (LiSN-S) with the Listening in Spatialised Noise - Universal test (LiSN-U).

Objective: The aim of this study was to correlate 6- to 7-year-old children's results on each condition of the Listening in Spatialised Noise - Sentences test (LiSN-S) with the new language-independent version, the Listening in Spatialised Noise - Universal test (LiSN-U), to examine the strength of the relationship between them and with memory in a small sample of typically developing children.Design: Correlational analysis.Study samples: Sixteen typically developing 6- to 7-year-old children completed the LiSN-S and LiSN-U as well as the Test of Auditory Processing Skills - Third Edition (TAPS-3) number memory forward and reversed subtests which assess short-term memory and working memory, respectively.Results: Moderate positive correlations were found between LiSN-S and LiSN-U spatially separated conditions (though this did not reach significance), and co-located conditions. Correlations between the LiSN-S and LiSN-U conditions and number memory forward and reversed subtests were not significant.Conclusion: This study shows a moderate relationship between the LiSN-S and LiSN-U when the distractors and target speech are co-located. A study with a larger sample of participants is needed to further understand the relationship between the two tests, especially for the spatially separated condition.

The relation of hearing-specific patient-reported outcome measures with speech perception measures and acceptable noise levels in cochlear implant users.

Objective: To investigate the relation of a hearing-specific patient-reported outcome measure (PROM) with speech perception and noise tolerance measurements. It was hypothesised that speech intelligibility in noise and noise tolerance may explain a larger part of the variance in PROM scores than speech intelligibility in quiet.Design: This cross-sectional study used the Speech, Spatial, Qualities (SSQ) questionnaire as a PROM. Speech recognition in quiet, the Speech Reception Threshold in noise and noise tolerance as measured with the acceptable noise level (ANL) were measured with sentences.Study sample: A group of 48 unilateral post-lingual deafened cochlear implant (CI) users.Results: SSQ scores were moderately correlated with speech scores in quiet and noise, and also with ANLs. Speech scores in quiet and noise were strongly correlated. The combination of speech scores and ANL explained 10-30% of the variances in SSQ scores, with ANLs adding only 0-9%.Conclusions: The variance in the SSQ as hearing-specific PROM in CI users was not better explained by speech intelligibility in noise than by speech intelligibility in quiet, because of the remarkably strong correlation between both measures. ANLs made only a small contribution to explain the variance of the SSQ. ANLs seem to measure other aspects than the SSQ.

Adult normative data for the speech in babble (SiB) test.

Objective: The Speech in Babble (SiB) test assesses the perception of speech in noise in UK adults. Here, we define the normal range of SiB scores to enable the use of the test in clinic.Design: In each test, 25 monosyllabic words were played in background multi-talker babble. Listeners had to repeat the word they heard. An adaptive procedure was used to determine the signal-to-noise ratio needed to reach 50% correct responses (i.e. the Speech Reception Threshold). Eight distinct equivalent lists were available.Study sample: Sixty-nine normal-hearing adults (aged 20-57 years) with no reported listening difficulties participated in the study and completed the SiB test twice in both ears.Results: Normative SiB scores varied from -0.8 dB to 3.7 dB suggesting that patients outside these limits should be considered as having abnormal scores. No statistically significant difference between ears and no effect of age or sex was found. There was "fair" test-retest reliability.Conclusion: The SiB test is a short, valid and reliable test that can be used in UK clinics, e.g. as part of a standard APD battery or evaluating the performance of hearing impaired patients.

British children's performance on the listening in spatialised noise-sentences test (LISN-S).

Objective: To investigate whether British children's performance is equivalent to North American norms on the listening in spatialised noise-sentences test (LiSN-S). Design: Prospective study comparing the performance of a single British group of children to North-American norms on the LiSN-S (North American version). Study sample: The British group was composed of 46 typically developing children, aged 6-11 years 11 months, from a mainstream primary school in London. Results: No significant difference was observed between the British's group performance and the North-American norms for Low-cue, High-cue, Spatial Advantage and Total Advantage measure. The British group presented a significantly lower performance only for Talker Advantage measure (z-score: 0.35, 95% confidence interval -0.12 to -0.59). Age was significantly correlated with all unstandardised measures. Conclusion: Our results indicate that, when assessing British children, it would be appropriate to add a corrective factor of 0.35 to the z-score value obtained for the Talker Advantage in order to compare it to the North-American norms. This strategy would enable the use of LiSN-S in the UK to assess auditory stream segregation based on spatial cues.

The NTID speech recognition test: NSRT(®).

OBJECTIVE: The purpose of this study was to collect and analyse data necessary for expansion of the NSRT item pool and to evaluate the NSRT adaptive testing software. DESIGN: Participants were administered pure-tone and speech recognition tests including W-22 and QuickSIN, as well as a set of 323 new NSRT items and NSRT adaptive tests in quiet and background noise. Performance on the adaptive tests was compared to pure-tone thresholds and performance on other speech recognition measures. The 323 new items were subjected to Rasch scaling analysis. STUDY SAMPLE: Seventy adults with mild to moderately severe hearing loss participated in this study. Their mean age was 62.4 years (sd = 20.8). RESULTS: The 323 new NSRT items fit very well with the original item bank, enabling the item pool to be more than doubled in size. Data indicate high reliability coefficients for the NSRT and moderate correlations with pure-tone thresholds (PTA and HFPTA) and other speech recognition measures (W-22, QuickSIN, and SRT). CONCLUSION: The adaptive NSRT is an efficient and effective measure of speech recognition, providing valid and reliable information concerning respondents' speech perception abilities.

Speech reception threshold benefits in cochlear implant users with an adaptive beamformer in real life situations.

OBJECTIVES: To compare the Naida CI UltraZoom adaptive beamformer and T-Mic settings in a real life environment. METHODS: Speech reception thresholds (SRTs) were measured in a moderately reverberant room, using the German Oldenburger sentence test. The speech signal was always presented from the front loudspeaker at 0° azimuth and fixed masking noise was presented either simultaneously from all eight loudspeakers around the subject at 0°, ±45°, ±90°, ±135°, and 180° azimuth or from five loudspeakers positioned at ±70°, ±135°, and 180° azimuth. In the third test setup, an additional roving noise was added to the six loudspeaker arrangement. RESULTS: There was a significant difference in mean SRTs between the Naida CI T-Mic and UltraZoom in each of the three test setups. The largest improvements were seen in the six speaker roving and fixed noise conditions. Adding ClearVoice to the Naida CI T-Mic setting significantly improved the SRT in both fixed noise conditions, but not in the roving noise condition. In each setup, the lowest SRTs were obtained with the UltraZoom plus ClearVoice setting. DISCUSSION: The degree of improvement was consistent with previous beamforming studies. In the most challenging listening situation, with noise from eight speakers and speech and noise presented coincidentally from the front, UltraZoom still provided a significant benefit. When a moving noise source was added, the improvement in SRT provided by UltraZoom was maintained. CONCLUSION: When tested in challenging and realistic noise environments, the Naida CI UltraZoom adaptive beamformer resulted in significantly lower mean SRTs than when the T-Mic alone was used.

Effects of hearing aid settings for electric-acoustic stimulation.

BACKGROUND: Cochlear implant (CI) recipients with postoperative hearing preservation may utilize an ipsilateral bimodal listening condition known as electric-acoustic stimulation (EAS). Studies on EAS have reported significant improvements in speech perception abilities over CI-alone listening conditions. Adjustments to the hearing aid (HA) settings to match prescription targets routinely used in the programming of conventional amplification may provide additional gains in speech perception abilities. PURPOSE: Investigate the difference in users' speech perception scores when listening with the recommended HA settings for EAS patients versus HA settings adjusted to match National Acoustic Laboratories' nonlinear fitting procedure version 1 (NAL-NL1) targets. RESEARCH DESIGN: Prospective analysis of the influence of HA settings. STUDY SAMPLE: Nine EAS recipients with greater than 12 mo of listening experience with the DUET speech processor. INTERVENTION: Subjects were tested in the EAS listening condition with two different HA setting configurations. Speech perception materials included consonant-nucleus-consonant (CNC) words in quiet, AzBio sentences in 10-talker speech babble at a signal-to-noise ratio (SNR) of +10, and the Bamford-Kowal-Bench sentences in noise (BKB-SIN) test. DATA COLLECTION AND ANALYSIS: The speech perception performance on each test measure was compared between the two HA configurations. RESULTS: Subjects experienced a significant improvement in speech perception abilities with the HA settings adjusted to match NAL-NL1 targets over the recommended HA settings. CONCLUSIONS: EAS subjects have been shown to experience improvements in speech perception abilities when listening to ipsilateral combined stimulation. This population's abilities may be underestimated with current HA settings. Tailoring the HA output to the patient's individual hearing loss offers improved outcomes on speech perception measures.

Prediction of IOI-HA scores using speech reception thresholds and speech discrimination scores in quiet.

BACKGROUND: Outcome measures can be used to improve the quality of the rehabilitation by identifying and understanding which variables influence the outcome. This information can be used to improve outcomes for clients. In clinical practice, pure-tone audiometry, speech reception thresholds (SRTs), and speech discrimination scores (SDSs) in quiet or in noise are common assessments made prior to hearing aid (HA) fittings. It is not known whether SRT and SDS in quiet relate to HA outcome measured with the International Outcome Inventory for Hearing Aids (IOI-HA). PURPOSE: The aim of the present study was to investigate the relationship between pure-tone average (PTA), SRT, and SDS in quiet and IOI-HA in both first-time and experienced HA users. RESEARCH DESIGN: SRT and SDS were measured in a sample of HA users who also responded to the IOI-HA. STUDY SAMPLE: Fifty-eight Danish-speaking adult HA users. DATA COLLECTION AND ANALYSIS: The psychometric properties were evaluated and compared to previous studies using the IOI-HA. The associations and differences between the outcome scores and a number of descriptive variables (age, gender, fitted monaurally/binaurally with HA, first-time/experienced HA users, years of HA use, time since last HA fitting, best ear PTA, best ear SRT, or best ear SDS) were examined. A multiple forward stepwise regression analysis was conducted using scores on the separate IOI-HA items, the global score, and scores on the introspection and interaction subscales as dependent variables to examine whether the descriptive variables could predict these outcome measures. RESULTS: Scores on single IOI-HA items, the global score, and scores on the introspection (items 1, 2, 4, and 7) and interaction (items 3, 5, and 6) subscales closely resemble those previously reported. Multiple regression analysis showed that the best ear SDS predicts about 18-19% of the outcome on items 3 and 5 separately, and about 16% on the interaction subscale (sum of items 3, 5, and 6) CONCLUSIONS: The best ears SDS explains some of the variance displayed in the IOI-HA global score and the interaction subscale. The relation between SDS and IOI-HA suggests that a poor unaided SDS might in itself be a limiting factor for the HA rehabilitation efficacy and hence the IOI-HA outcome. The clinician could use this information to align the user's HA expectations to what is within possible reach.

No learning effect observed for reception thresholds for sentences in noise.

PURPOSE: This study examined reception thresholds for sentences (RTSs) as a function of test session (N = 5) and noise (continuous and interrupted) in normal-hearing adults. It was hypothesized that RTSs would be superior in interrupted noise and would be stable across repeated testing. METHOD: Twenty-five normal-hearing adults participated. RTSs were determined with Hearing in Noise Test sentences in continuous and interrupted noise presented at 65 dBA. An adaptive technique was used where sentences varied in intensity to converge on a level of 50% of correct performance. Sentence lists were counterbalanced with 5 unique lists in both continuous and interrupted noise. RESULTS: RTS signal-to-noise ratios were significantly better in the interrupted noise (p < .0001). There was no effect of test session (p = .12) or a Test Session × Noise interaction (p = .13). CONCLUSIONS: Stable RTS signal-to-noise ratios across test sessions in both noises are consistent with the notion that a learning effect was not present in noise. Further, one may conclude that Hearing in Noise Test sentences provide stable measures of sentence recognition thresholds in normal-hearing adults over time so long as sentences are unique or are not repeated.

Digit speech recognition threshold (SRT) in children with normal hearing ages 5-8 years.

PURPOSE: The purpose of this study was to compare digit stimuli to popular spondees when measuring speech recognition threshold (SRT) in children with normal hearing and to determine the influence of increment size using a descending method (ASHA, 1988). METHOD: SRT was measured with paired digit stimuli (D-SRT) and pediatric word stimuli (W-SRT) using 2 step sizes (5 dB, 2 dB) in 30 typically developing children with normal hearing ages 5;0 (years;months) to 8;11. Pure-tone and SRT tests were administered in both ears. The D-SRT and W-SRT were compared to pure-tone average (PTA) thresholds per ear. RESULTS: Analysis of variance revealed a significant interaction of test and step size: PTA was significantly lower when measured with 2-dB than with 5-dB increment; however, step size yielded no differences in D-SRT and W-SRT. Right ear thresholds across tests were significantly lower than left ear. Pearson correlations were significant for all tests except two; D-SRT was highly correlated to W-SRT (r = .49-.72) in both ears. Regression analyses for both ears and step sizes revealed that prediction of the hearing threshold for speech from PTA was equally accurate for SRT measured with digit pairs or popular pediatric spondee stimuli. CONCLUSION: Digit pairs are an appropriate alternative stimulus for SRT measurement in children with normal hearing. Future diagnostic audiology implications, including application for other pediatric populations, are discussed.

Factors influencing individual variation in perceptual directional microphone benefit.

BACKGROUND: Large variations in perceptual directional microphone benefit, which far exceed the variation expected from physical performance measures of directional microphones, have been reported in the literature. The cause for the individual variation has not been systematically investigated. PURPOSE: To determine the factors that are responsible for the individual variation in reported perceptual directional benefit. RESEARCH DESIGN: A correlational study. Physical performance measures of the directional microphones obtained after they had been fitted to individuals, cognitive abilities of individuals, and measurement errors were related to perceptual directional benefit scores. STUDY SAMPLE: Fifty-nine hearing-impaired adults with varied degrees of hearing loss participated in the study. DATA COLLECTION AND ANALYSIS: All participants were bilaterally fitted with a Motion behind-the-ear device (500 M, 501 SX, or 501 P) from Siemens according to the National Acoustic Laboratories' non-linear prescription, version two (NAL-NL2). Using the Bamford-Kowal-Bench (BKB) sentences, the perceptual directional benefit was obtained as the difference in speech reception threshold measured in babble noise (SRTn) with the devices in directional (fixed hypercardioid) and in omnidirectional mode. The SRTn measurements were repeated three times with each microphone mode. Physical performance measures of the directional microphone included the angle of the microphone ports to loudspeaker axis, the frequency range dominated by amplified sound, the in situ signal-to-noise ratio (SNR), and the in situ three-dimensional, articulation-index weighted directivity index (3D AI-DI). The cognitive tests included auditory selective attention, speed of processing, and working memory. Intraparticipant variation on the repeated SRTn's and the interparticipant variation on the average SRTn were used to determine the effect of measurement error. A multiple regression analysis was used to determine the effect of other factors. RESULTS: Measurement errors explained 52% of the variation in perceptual directional microphone benefit (95% confidence interval [CI]: 34-78%), while another 37% of variation was explained primarily by the physical performance of the directional microphones after they were fitted to individuals. The most contributing factor was the in situ 3D AI-DI measured across the low frequencies. CONCLUSIONS: Repeated SRTn measurements are needed to obtain a reliable indication of the perceptual directional benefit in an individual. Further, to obtain optimum benefit from directional microphones, the effectiveness of the microphones should be maximized across the low frequencies.

Sentence recognition in noise and perceived benefit of noise reduction on the receiver and transmitter sides of a BICROS hearing aid.

BACKGROUND: In the past, bilateral contralateral routing of signals (BICROS) amplification incorporated omnidirectional microphones on the transmitter and receiver sides and some models utilized noise reduction (NR) on the receiver side. Little research has examined the performance of BICROS amplification in background noise. However, previous studies examining contralateral routing of signals (CROS) amplification have reported that the presence of background noise on the transmitter side negatively affected speech recognition. Recently, NR was introduced as a feature on the receiver and transmitter sides of BICROS amplification, which has the potential to decrease the impact of noise on the wanted speech signal by decreasing unwanted noise directed to the transmitter side. PURPOSE: The primary goal of this study was to examine differences in the reception threshold for sentences (RTS in dB) using the Hearing in Noise Test (HINT) in a diffuse listening environment between unaided and three aided BICROS conditions (no NR, mild NR, and maximum NR) in the Tandem 16 BICROS. A secondary goal was to examine real-world subjective impressions of the Tandem 16 BICROS compared to unaided. RESEARCH DESIGN: A randomized block repeated measures single blind design was used to assess differences between no NR, mild NR, and maximum NR listening conditions. STUDY SAMPLE: Twenty-one adult participants with asymmetric sensorineural hearing loss (ASNHL) and experience with BICROS amplification were recruited from Washington University in St. Louis School of Medicine. DATA COLLECTION AND ANALYSIS: Participants were fit with the National Acoustic Laboratories' Nonlinear version 1 prescriptive target (NAL-NL1) with the Tandem 16 BICROS at the initial visit and then verified using real-ear insertion gain (REIG) measures. Participants acclimatized to the Tandem 16 BICROS for 4 wk before returning for final testing. Participants were tested utilizing HINT sentences examining differences in RTS between unaided and three aided listening conditions. Subjective benefit was determined via the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire between the Tandem 16 BICROS and unaided. A repeated measures analysis of variance (ANOVA) was utilized to analyze the results of the HINT and APHAB. RESULTS: Results revealed no significant differences in the RTS between unaided, no NR, mild NR, and maximum NR. Subjective impressions using the APHAB revealed statistically and clinically significant benefit with the Tandem 16 BICROS compared to unaided for the Ease of Communication (EC), Background Noise (BN), and Reverberation (RV) subscales. CONCLUSIONS: The RTS was not significantly different between unaided, no NR, mild NR, and maximum NR. None of the three aided listening conditions were significantly different from unaided performance as has been reported for previous studies examining CROS hearing aids. Further, based on comments from participants and previous research studies with conventional hearing aids, manufacturers of BICROS amplification should consider incorporating directional microphones and independent volume controls on the receiver and transmitter sides to potentially provide further improvement in signal-to-noise ratio (SNR) for patients with ASNHL.

Clinical experience with the words-in-noise test on 3430 veterans: comparisons with pure-tone thresholds and word recognition in quiet.

BACKGROUND: Since the 1940s, measures of pure-tone sensitivity and speech recognition in quiet have been vital components of the audiologic evaluation. Although early investigators urged that speech recognition in noise also should be a component of the audiologic evaluation, only recently has this suggestion started to become a reality. This report focuses on the Words-in-Noise (WIN) Test, which evaluates word recognition in multitalker babble at seven signal-to-noise ratios and uses the 50% correct point (in dB SNR) calculated with the Spearman-Kärber equation as the primary metric. The WIN was developed and validated in a series of 12 laboratory studies. The current study examined the effectiveness of the WIN materials for measuring the word-recognition performance of patients in a typical clinical setting. PURPOSE: To examine the relations among three audiometric measures including pure-tone thresholds, word-recognition performances in quiet, and word-recognition performances in multitalker babble for veterans seeking remediation for their hearing loss. RESEARCH DESIGN: Retrospective, descriptive. STUDY SAMPLE: The participants were 3430 veterans who for the most part were evaluated consecutively in the Audiology Clinic at the VA Medical Center, Mountain Home, Tennessee. The mean age was 62.3 yr (SD = 12.8 yr). DATA COLLECTION AND ANALYSIS: The data were collected in the course of a 60 min routine audiologic evaluation. A history, otoscopy, and aural-acoustic immittance measures also were included in the clinic protocol but were not evaluated in this report. RESULTS: Overall, the 1000-8000 Hz thresholds were significantly lower (better) in the right ear (RE) than in the left ear (LE). There was a direct relation between age and the pure-tone thresholds, with greater change across age in the high frequencies than in the low frequencies. Notched audiograms at 4000 Hz were observed in at least one ear in 41% of the participants with more unilateral than bilateral notches. Normal pure-tone thresholds (≤20 dB HL) were obtained from 6% of the participants. Maximum performance on the Northwestern University Auditory Test No. 6 (NU-6) in quiet was ≥90% correct by 50% of the participants, with an additional 20% performing at ≥80% correct; the RE performed 1-3% better than the LE. Of the 3291 who completed the WIN on both ears, only 7% exhibited normal performance (50% correct point of ≤6 dB SNR). Overall, WIN performance was significantly better in the RE (mean = 13.3 dB SNR) than in the LE (mean = 13.8 dB SNR). Recognition performance on both the NU-6 and the WIN decreased as a function of both pure-tone hearing loss and age. There was a stronger relation between the high-frequency pure-tone average (1000, 2000, and 4000 Hz) and the WIN than between the pure-tone average (500, 1000, and 2000 Hz) and the WIN. CONCLUSIONS: The results on the WIN from both the previous laboratory studies and the current clinical study indicate that the WIN is an appropriate clinic instrument to assess word-recognition performance in background noise. Recognition performance on a speech-in-quiet task does not predict performance on a speech-in-noise task, as the two tasks reflect different domains of auditory function. Experience with the WIN indicates that word-in-noise tasks should be considered the "stress test" for auditory function.

[Indication for and verification of hearing aid benefit using modern methods of speech audiometry in German]. / Hörgeräteindikation und -überprüfung nach modernen Verfahren der Sprachaudiometrie im Deutschen.

The current guidelines for hearing aid supply in Germany employ the often criticised Freiburg monosyllabic speech test (FBE) in quiet. This test can be replaced with the monosyllabic rhyme test by von Wallenberg and Kollmeier (WaKo) in quiet and by the measurement of a speech reception threshold in an interfering noise at a moderate level (45 dB SPL) using either the Göttingen or the Oldenburg sentence test (criterion: 2 dB improvement in SNR, "signal-to-noise ratio"). This procedure was investigated in a group of 38 participants with a sensorineural hearing impairment (mild, moderate or severe hearing loss) and 11 volunteers with normal hearing. On average, comparable indications were achieved. Participants with a mild hearing loss and a selective problem with listening in interfering noise were assessed more fairly.

Development and evaluation of a computerized Mandarin speech test system in China.

OBJECTIVES: This study reports the development and evaluation of a Computerized Mandarin Speech Test System (CMSTS). METHODS: Taking into account the rules for developing speech materials and the unique linguistic characteristics of Mandarin, we designed and digitally recorded a set of materials comprised of seven lists of monosyllabic words, nine lists of disyllabic words, and fifteen lists of sentences with a high degree of subject familiarity. The CMSTS was developed with Visual Studio 2008, Access 2003 and DirectX 9. The system included five functions: listener management, a speech test, list management, data management, and system settings. We used the system to measure the speech recognition threshold (SRT) of 76 participants with normal hearing (age range: 20-28 years), and measured performance-intensity functions (PI) for all stimuli. RESULTS: The SRT results were in accord with pure-tone results obtained by pure-tone audiometry. In a speech recognition score (SRS) test, changing the presentation level had the strongest effect on sentence recognition, followed by the presence of disyllabic words. Monosyllabic words were least affected by changes in presentation level. The slopes of the linear portion of the PI using the system were in accord with the findings of previous studies using audiometers and CDs with similar materials. CONCLUSION: The CMSTS has sufficient sensitivity, and can facilitate the wider use of speech audiometry in Chinese audiology clinics.

Auditory processing disorder and speech perception problems in noise: finding the underlying origin.

PURPOSE: A hallmark listening problem of individuals presenting with auditory processing disorder (APD) is their poor recognition of speech in noise. The underlying perceptual problem of the listening difficulties in unfavorable listening conditions is unknown. The objective of this article was to demonstrate theoretically how to determine whether the speech recognition problems are related to an auditory dysfunction, a language-based dysfunction, or a combination of both. METHOD: Tests such as the Speech Perception in Noise (SPIN) test allow the exploration of the auditory and language-based functions involved in speech perception in noise, which is not possible with most other speech-in-noise tests. Psychometric functions illustrating results from hypothetical groups of individuals with APD on the SPIN test are presented. This approach makes it possible to postulate about the origin of the speech perception problems in noise. CONCLUSION: APD is a complex and heterogeneous disorder for which the underlying deficit is currently unclear. Because of their design, SPIN-like tests can potentially be used to identify the nature of the deficits underlying problems with speech perception in noise for this population. A better understanding of the difficulties with speech perception in noise experienced by many listeners with APD should lead to more efficient intervention programs.

The homogeneity of audibility and prosody of Zulu words for speech reception threshold (SRT) testing.

The aim of this investigation was to determine which of 58 preselected Zulu words developed by Panday et al. (2007) could be used for Speech Reception Threshold (SRT) testing. To realize this aim the homogeneity of audibility of 58 bisyllabic Zulu low tone verbs was measured, followed by an analysis of the prosodic features of the selected words. The words were digitally recorded by a Zulu first language male speaker and presented at 6 intensity levels to 30 Zulu first language speakers (18-25 years, mean age of 21.5 years), whose hearing was normal. Homogeneity of audibility was determined by employing logistic regression analysis. Twenty eight words met the criterion of homogeneity of audibility. This was evidenced by a mean slope of 50% at 5.98%/dB. The prosodic features of the twenty eight words were further analyzed using a computerized speech laboratory system. The findings confirmed that the pitch contours of the words followed the prosodic pattern apparent within Zulu linguistic structure. Eighty nine percent of the Zulu verbs were found to have a difference in the pitch pattern between the two syllables i.e. the first syllable was low in pitch, while the second syllable was high in pitch. It emerged that the twenty eight words could be used for establishing SRT within a normal hearing Zulu speaking population. Further research within clinical populations is recommended.

Establishment of age-specific normative data for the canadian French version of the hearing in noise test for children.

OBJECTIVES: A Canadian French version of the Hearing in Noise Test (HINT) has been developed to assess children's ability to recognize speech in noise. To avoid testing a large number of children in each clinical test site to establish soundfield norms, a protocol based on the use of correction factors has been proposed and validated in the current study. More specifically, the objective of this study was to provide a protocol for the establishment of age-specific normative data for the Canadian French HINT for children to facilitate its clinical use and allow comparing an individual child's performance with that of age-matched normal hearing children. Using the proposed protocol, a limited number of normal hearing adults are tested in each HINT condition to correct the adult headphone norms for the soundfield in question, and the correction factors established in the current study are then applied to generate age-specific soundfield norms. Mean adult performance values obtained in a given soundfield are entered into the HINT software, which automatically derives the soundfield adult norms, age-specific children norms, and percentile rankings. DESIGN: Speech reception thresholds (SRT) for sentences were measured in 70 native French-speaking subjects to establish mean performances across various age groups, and correction factors were calculated by comparing performance in each age group with adult performance. To validate the normalization protocol, 28 additional subjects were tested in a new soundfield. The correction factors were applied to adult performance (N = 15) and the resulting predicted scores were compared with measured performance in a group of 9-yr olds (N = 13). RESULTS: Statistical analyses indicate that SRTs decrease with age and reach adult values in older children (12-yr olds). Correction factors are therefore provided for children 6 to 12 yrs old. Spatial separation advantage, the improvement in SRT when speech and noise are spatially separated, also improves with age. The correction factors were effective in predicting mean SRTs for a previously untested age group in all HINT conditions apart from the quiet condition. The difference between predicted and measured performances was less than 0.5 dB for the noise conditions but exceeded 4 dB in the quiet condition. The reliability of SRT measures was determined, with an overall within-subjects SD of repeated measurements of 0.7 dB for the noise front condition. No learning effect was found in the current data. CONCLUSIONS: Correction factors can be used to predict performance on the HINT in a group of normal-hearing children in all HINT conditions, apart from quiet. Findings of the current study concur with the literature on age effects in auditory processing abilities, where performance on a variety of auditory tasks has been demonstrated to increase with age to reach adult-like values in adolescence or past 10 yrs.

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.

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 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 (< or = 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 approximately 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).