An Italian matrix sentence test for the evaluation of speech intelligibility in noise

Objective: Development of an Italian matrix sentence test for the assessment of speech intelligibility in noise. Design: The development of the test included the selection, recording, optimization with level adjustment, and evaluation of speech material. The training effect was assessed adaptively during the evaluation measurements with six lists of 20 sentences, using open- and closed-set response formats. Reference data were established for normal-hearing listeners with adaptive measurements. Equivalence of the test lists was investigated using the open-set response format at three signal-to-noise ratios (SNRs). Study sample: A total of 55 normal-hearing Italian mother-tongue listeners. Results: The evaluation measurements at fixed SNRs resulted in a mean speech reception threshold (SRT) of ? 7.3 ± 0.2 dB SNR and slope of 13.3 ± 1.2 %/dB. The major training effect of 1.5 dB was observed for the first two consecutive measurements. Mean SRTs of ? 6.7 ± 0.7 dB SNR and ? 7.4 ± 0.7 dB SNR were found from the third to the sixth adaptive measurement for open- and closed-set test response formats, respectively. Conclusions: A good agreement has been found between the SRTs and slope and those of other matrix tests. Since sentences are difficult to memorize, the Italian matrix test is suitable for repeated measurements.     

Development of the Russian matrix sentence test

Objective: To develop the Russian matrix sentence test for speech intelligibility measurements in noise. Design: Test development included recordings, optimization of speech material, and evaluation to investigate the equivalency of the test lists and training. For each of the 500 test items, the speech intelligibility function, speech reception threshold (SRT: signal-to-noise ratio, SNR, that provides 50% speech intelligibility), and slope was obtained. The speech material was homogenized by applying level corrections. In evaluation measurements, speech intelligibility was measured at two fixed SNRs to compare list-specific intelligibility functions. To investigate the training effect and establish reference data, speech intelligibility was measured adaptively. Study sample: Overall, 77 normal-hearing native Russian listeners. Results: The optimization procedure decreased the spread in SRTs across words from 2.8 to 0.6 dB. Evaluation measurements confirmed that the 16 test lists were equivalent, with a mean SRT of ? 9.5 ± 0.2 dB and a slope of 13.8 ± 1.6%/dB. The reference SRT, ? 8.8 ± 0.8 dB for the open-set and ? 9.4 ± 0.8 dB for the closed-set format, increased slightly for noise levels above 75 dB SPL. Conclusions: The Russian matrix sentence test is suitable for accurate and reliable speech intelligibility measurements in noise.     

Development and evaluation of the Turkish matrix sentence test

Objectives: The Turkish matrix sentence test, TURMatrix, was developed for precise, internationally comparable speech intelligibility testing. Design: The TURMatrix comprises a base matrix of ten well-known Turkish names, numbers, adjectives, objects, verbs, from which syntactically fixed sentences were randomly composed. Test conduction may be in an open-set (standard), or closed-set response format. Homogeneity in intelligibility of the test material was optimized by applying level adaptations (maximal ± 3 dB) based on word-specific speech reception thresholds (SRTs). Test list equivalence was verified and reference values were determined. Study sample: Thirty-eight native listeners of Turkish with normal hearing. Results: After training, mean SRT and slope of the final test lists were ? 8.3 ± 0.2 dB SNR and 14.1 ± 1.0%/dB, respectively (fixed SNR measurements; inter-list variability). For adaptive measurements, average across listeners was ? 7.2 ± 0.7 dB SNR in the open-set and ? 7.9 ± 0.7 dB SNR in the closed-set response format. Mean SRT for adaptive measurements in the open-set response format in quiet was 20.3 ± 4.1 dB. Individual SRTs in quiet correlated more closely with audiograms than with SRTs in noise. Conclusions: The TURMatrix was developed according to European standards and provides reliable speech intelligibility measurements in noise and quiet.     

The development and evaluation of the Finnish digit triplet test

Objectives: The aim of the study was to develop a reliable and easily accessible screening test for primary detection of hearing impairment.

Methods: Digits 0–9 were used to form quasirandom digit triplets. First, digit specific intelligibility functions and speech recognition thresholds (SRTs) were determined. To homogenize the test material digits with steep intelligibility function slopes were chosen and level correction up to ±2?dB were applied to the digits as needed. Evaluation measurements were performed to check for systematic differences in intelligibility between the test lists and to obtain normative reference function for normal-hearing listeners.

Results: The mean SRT and the final slope of the test lists were ?10.8?±?0.1?dB signal-to-noise ratio (SNR) and 21.7?±?1.8%/dB, respectively (measurements at constant level; inter-list variability). The mean SRT and slope of the test subjects were ?10.8?±?0.5?dB SNR and 23.4?±?5.2%/dB (measurements at constant level; inter-subject variability). The mean SRT for normal-hearing young adults for a single adaptive measurement is ?9.8?±?0.9?dB SNR.

Conclusion: The Finnish digit triplet test is the first self-screening hearing test in the Finnish language. It was developed according to current standards, and it provides reliable and internationally comparable speech intelligibility measurements.     

A Spanish matrix sentence test for assessing speech reception thresholds in noise

Objective: To develop, optimize, and evaluate a new Spanish sentence test in noise. Design: The test comprises a basic matrix of ten names, verbs, numerals, nouns, and adjectives. From this matrix, test lists of ten sentences with an equal syntactical structure can be formed at random, with each list containing the whole speech material. The speech material represents the phoneme distribution of the Spanish language. The test was optimized for measuring speech reception thresholds (SRTs) in noise by adjusting the presentation levels of the individual words. Subsequently, the test was evaluated by independent measurements investigating the training effects, the comparability of test lists, open-set vs. closed-set test format, and performance of listeners of different Spanish varieties. Study sample: In total, 68 normal-hearing native Spanish-speaking listeners. Results: SRTs measured using an adaptive procedure were 6.2 ± 0.8 dB SNR for the open-set and 7.2 ± 0.7 dB SNR for the closed-set test format. The residual training effect was less than 1 dB after using two double-lists before data collection. Conclusions: No significant differences were found for listeners of different Spanish varieties indicating that the test is applicable to Spanish as well as Latin American listeners. Test lists can be used interchangeably.     

Influence of noise type on speech reception thresholds across four languages measured with matrix sentence tests

Objective: To compare speech reception thresholds (SRTs) in noise using matrix sentence tests in four languages: German, Spanish, Russian, Polish. Design: The four tests were composed of equivalent five-word sentences and were all designed and optimized using the same principles. Six stationary speech-shaped noises and three non-stationary noises were used as maskers. Study sample: Forty native listeners with normal hearing: 10 for each language. Results: SRTs were about 3 dB higher for the German and Spanish tests than for the Russian and Polish tests when stationary noise was used that matched the long-term frequency spectrum of the respective speech test materials. This general SRT difference was also observed for the other stationary noises. The within-test variability across noise conditions differed between languages. About 56% of the observed variance was predicted by the speech intelligibility index. The observed SRT benefit in fluctuating noise was similar for all tests, with a slightly smaller benefit for the Spanish test. Conclusions: Of the stationary noises employed, noise with the same spectrum as the speech yielded the best masking. SRT differences across languages and noises could be attributed in part to spectral differences. These findings provide the feasibility and limits of comparing audiological results across languages.     

Do you hear the noise? The German matrix sentence test with a fixed noise level in subjects with normal hearing and hearing impairment

Objective: The aim of this study was to determine the relationship between hearing loss and speech reception threshold (SRT) in a fixed noise condition using the German Oldenburg sentence test (OLSA). Design: After training with two easily-audible lists of the OLSA, SRTs were determined monaurally with headphones at a fixed noise level of 65 dB SPL using a standard adaptive procedure, converging to 50% speech intelligibility. Study sample: Data was obtained from 315 ears of 177 subjects with hearing losses ranging from ? 5 to 90 dB HL pure-tone average (PTA, 0.5, 1, 2, 3 kHz). Results: Two domains were identified with a linear dependence of SRT on PTA. The SRT increased with a slope of 0.094 ± 0.006 dB SNR/dB HL (standard deviation (SD) of residuals = 1.17 dB) for PTAs < 47 dB HL and with a slope of 0.811 ± 0.049 dB SNR/dB HL (SD of residuals = 5.54 dB) for higher PTAs. Conclusion: The OLSA can be applied to subjects with a wide range of hearing losses. With 65 dB SPL fixed noise presentation level the SRT is determined by listening in noise for PTAs < ～47 dB HL, and above it is determined by listening in quiet.     

Construction and evaluation of the Mandarin Chinese matrix (CMNmatrix) sentence test for the assessment of speech recognition in noise

Abstract

Objective: Development of the Mandarin Chinese matrix (CMNmatrix) sentence test for speech intelligibility measurements in noise according to the international standard procedure.

Design: A 50-word base matrix representing the distribution of phonemes and lexical tones of spoken Mandarin was established. Hundred sentences capturing all the co-articulations of two consecutive words were recorded. Word-specific speech recognition functions, speech reception thresholds (SRT: signal-to-noise ratio (SNR), that provides 50% speech intelligibility) and slopes were obtained from measurements at fixed SNRs. The speech material was homogenised in intelligibility by applying level corrections up to ± 2?dB. Subsequently, the CMNmatrix test was evaluated, the comparability of test lists was measured at two fixed SNRs. To investigate the training effect and establish the reference data, speech recognition was measured adaptively.

Study sample: Overall, the study sample contained 80 normal-hearing native Mandarin-speaking listeners.

Results: Multi-centre evaluation measurements confirmed that test lists are equivalent in intelligibility, with a mean SRT of ?10.1?±?0.1?dB SNR and a slope of 13.1?±?0.9 %/dB. The reference SRT is ?9.3?±?0.8 and ?11.2?±?1.2?dB SNR for the open- and closed-set response format, respectively.

Conclusion: The CMNmatrix test is suitable for accurate and internationally comparable speech recognition measurements in noise.     

The French digit triplet test: A hearing screening tool for speech intelligibility in noise

Abstract

A French speech intelligibility screening test in noise that applies digit triplets as stimuli has been developed and evaluated for both telephone and broadband headphone use. After optimizing the speech material based on the intelligibility of the individual digits, norms for normal-hearing subjects were established. speech reception thresholds (SRTs) of ?6.4 ± 0.4 and ?10.5 ± 0.3 dB SNR, and slopes of 17.1 and 27.1 %/dB were obtained for telephone and broadband headphone presentation, respectively. The French digit triplet test by telephone was then implemented as an automatic self-screening test by home telephone, and further evaluated in normal-hearing and hearing-impaired listeners. A test-retest variability of 0.7 dB was found and the correlation between SRT and pure-tone average (PTA_0.5,1,2,4) was 0.77. One month after launching the test, 20 000 calls were registered. It can be concluded that both versions of the newly developed test have steep slopes and small SRT differences across normal-hearing listeners. The screening test by telephone is highly reliable and proves to fulfill the need for an easily accessible and objective hearing screening.

Sumario

Se desarrolló y evaluó una prueba de tamiz de inteligibilidad del lenguaje en ruido, utilizando ternas de dígitos como estímulo, tanto para teléfono como para auriculares de banda ancha. Después de optimizar el material lingüístico basado en la inteligibilidad de los dígitos individuales, se establecieron las normas para los sujetos normoyentes. Se obtuvieron umbrales de recepción del lenguaje (SRTs) de -6.4 ± 0.4 y -10.5 ± 0.3dB SNR y pendientes de 17.1 y 27.1%/dB para teléfono y auriculares de banda ancha, respectivamente. Se implementó la prueba de terna de dígitos en francés por teléfono como una prueba de tamiz autoaplicable por teléfono en casa y después se evaluó en normoyentes e hipoacúsicos. Se encontró una variabilidad de test-re-test de 0.7 dB y la correlación entre SRT y el promedio de tonos puros (PTA_0.5,1,2,4) fue de 0.77. Un mes después de lanzar la prueba, se registraron 20,000 llamadas. Se puede concluir que ambas versiones de la prueba recientemente desarrollada tiene pendientes pronunciadas y pequeñas diferencias del SRT entre los normoyentes. La prueba de tamiz por teléfono es altamente confiable y demuestra que satisface las necesidades de una prueba de tamiz auditivo fácil, accesible y objetiva.     

The development of the University of Jordan word recognition test

Objective: To develop and validate a digitally recorded speech test battery to assess speech perception in Jordanian Arabic-speaking adults.

Design: Selected stimuli were digitally recorded and were divided into four lists of 25 words each. Speech audiometry was completed for all listeners. Participants were divided into two equal groups of 30 listeners each with equal male to female ratio. The first group of participants completed speech reception thresholds (SRTs) and word recognition testing on each of the four lists using a fixed intensity. The second group of listeners was tested on each of the four lists at different intensity levels in order to obtain the performance-intensity function. Study sample: Sixty normal-hearing listeners in the age range of 19–25 years. All participants were native speakers of Jordanian Arabic. Results: Results revealed that there were no significant differences between SRTs and pure tone average. Additionally, there were no differences across lists at multiple intensity levels. Conclusions: In general, the current study was successful in producing recorded speech materials for Jordanian Arabic population. This suggests that the speech stimuli generated by this study are suitable for measuring speech recognition in Jordanian Arabic-speaking listeners.     

普通话双音节测听词表在不同年龄听力正常人中的检测结果分析

目的:观察普通话言语测听材料中的1组双音节词汇表在不同年龄段听力正常人中的检测结果。探讨不同年龄听力正常人的言语识别阈(SRT)以及言语识别率与给声强度间的关系(P-I函数曲线),为临床听力康复及言语能力的评估提供参考依据。方法:将受试者(听力正常人)120例分成4个年龄组,采用9张双音节词汇表作为言语测试材料,分别测试每组的SRT和言语识别率与给声强度间的关系(P-I函数曲线)。结果:各组SRT与平均听力阈值(PTA)基本一致。18～30岁组、31～40岁组和41～50岁组随着年龄的增长,PTA阈值变化不明显,仅51～60岁组PTA阈值明显增高(P<0.01)。18～30岁组、31～40岁组和41～50岁组SRT阈值随着年龄增长而提高(P<0.05),仅51～60岁组SRT阈值明显增高(P<0.01)。不同年龄组的P-I函数曲线平均斜率分别为5.8%/dB、4.7%/dB、3.8%/dB、2.9%/dB。结论:将9张双音节普通话测试词表应用于不同年龄段的听力正常人,获得4个不同年龄组的SRT和识别-强度函数曲线,随着年龄的增加,SRT阈值提高,平均斜率下降,51～60岁组的PTA及SRT阈值增高较明显。该结论为今后临床推广应用普通话言语测听材料提供了正常人言语听力的参考标准。     

The effect of fluctuating maskers on speech understanding of high-performing cochlear implant users

Objective: The present study evaluated whether the poorer baseline performance of cochlear implant (CI) users or the technical and/or physiological properties of CI stimulation are responsible for the absence of masking release. Design: This study measured speech reception thresholds (SRTs) in continuous and modulated noise as a function of signal to noise ratio (SNR). Study sample: A total of 24 subjects participated: 12 normal-hearing (NH) listeners and 12 subjects provided with recent MED-EL CI systems. Results: The mean SRT of CI users in continuous noise was??3.0?±?1.5 dB SNR (mean?±?SEM), while the normal-hearing group reached??5.9?±?0.8 dB SNR. In modulated noise, the difference across groups increased considerably. For CI users, the mean SRT worsened to??1.4?±?2.3 dB SNR, while it improved for normal-hearing listeners to??18.9?±?3.8 dB SNR. Conclusions: The detrimental effect of fluctuating maskers on SRTs in CI users shown by prior studies was confirmed by the current study. Concluding, the absence of masking release is mainly caused by the technical and/or physiological properties of CI stimulation, not just the poorer baseline performance of many CI users compared to normal-hearing subjects. Speech understanding in modulated noise was more robust in CI users who had a relatively large electrical dynamic range.     

Characteristics and international comparability of the Finnish matrix sentence test in cochlear implant recipients

Objectives: The first Finnish sentence-based speech test in noise—the Finnish matrix sentence test—was recently developed. The aim of this study was to determine the characteristics of the new test with respect to test-retest reliability, speech recognition curve, and international comparability in Finnish cochlear implant (CI) recipients. Design: The speech reception thresholds (SRT) were measured by means of an adaptive test procedure and compared with the results of the traditional Finnish word test. Additional measurements for concurrent slope and SRT estimation were conducted to determine the speech recognition curve and to check the test-retest reliability. Study sample: The measurements were performed on 78 Finnish CI recipients. In a subset of 25 patients, additional measurements for test-retest reliability and slope determination were performed. Results: The mean SRT was ? 3.5 ± 1.7 dB SNR, with only a weak correlation with the Finnish word test. Test-retest reliability was within ± 1 dB and the mean slope of the speech recognition curve was 14.6 ± 3.6 %/dB. The rehabilitation results were similar to the results published for the German matrix test. Conclusions: The Finnish matrix test was found to be suitable and efficient in CI recipients with similar characteristics as the German matrix test.     

To measure the impact of hearing protectors on the perception of speech in noise

Abstract

Objective: To propose and evaluate a new method for assessing the potential impact on speech intelligibility when wearing a hearing protection device (HPD) in a noisy environment. Design: The method is based on a self adaptive method for finding the speech reception threshold (SRT) using speech material from the Callsign acquisition test (CAT) presented at a constant level while adjusting the level of a background noise. A key point is to primarily examine the impact of the HPD; i.e. the difference between occluded and unoccluded SRTs, presented as the speech intelligibility impact level. Study sample: A total of 31 test subjects. Results: The method is shown to be stable, with a minimum amount of learning effect, and capable of detecting differences between hearing protection devices. It is also shown that low-attenuation passive HPDs are likely to have a very small effect on speech intelligibility in noise, and that an electronic HPD with a level-dependant function has the potential to improve intelligibility. Conclusions: The results are encouraging regarding the precision, repeatability, and applicability of the proposed method.     

Evaluation of an internet-based speech-in-noise screening test for school-age children

Objective: To evaluate a Dutch online speech-in-noise screening test (in Dutch: “Kinderhoortest”) in normal-hearing school-age children. Sub-aims were to study test–retest reliability, and the effects of presentation type and age on test results. Design: An observational cross-sectional study at school. Speech reception thresholds (SRTs) were obtained through the online test in a training condition, and two test conditions: on a desktop computer and smartphone. The order of the test conditions was counterbalanced. Study sample: Ninety-four children participated (5–12 years), of which 75 children were normal-hearing (≤25?dB HL at 0.5?kHz,?≤20?dB HL at 1–4?kHz). Results: There was a significant effect for test order for the two test conditions (first or second test), but not for presentation type (desktop computer or smartphone) (repeated measures analyses, F(1,75)?=?12.48, p?F(1,75)?=?0.01, p?=?0.982). SRT significantly improved by age year (first test: 0.25?dB SNR, 95% CI: –0.43 to –0.08, p?=?0.004. Second test: 0.29?dB SNR, 95% CI: –0.46 to –0.11; p?=?0.002). Conclusions: The online test shows potential for routine-hearing screening of school-age children, and can be presented on either a desktop computer or smartphone. The test should be evaluated further in order to establish sensitivity and specificity for hearing loss in children.     

How much does language proficiency by non-native listeners influence speech audiometric tests in noise?

Objective: The current study investigates the extent to which the linguistic complexity of three commonly employed speech recognition tests and second language proficiency influence speech recognition thresholds (SRTs) in noise in non-native listeners. Design: SRTs were measured for non-natives and natives using three German speech recognition tests: the digit triplet test (DTT), the Oldenburg sentence test (OLSA), and the Göttingen sentence test (GÖSA). Study sample: Sixty-four non-native and eight native listeners participated. Results: Non-natives can show native-like SRTs in noise only for the linguistically easy speech material (DTT). Furthermore, the limitation of phonemic-acoustical cues in digit triplets affects speech recognition to the same extent in non-natives and natives. For more complex and less familiar speech materials, non-natives, ranging from basic to advanced proficiency in German, require on average 3-dB better signal-to-noise ratio for the OLSA and 6-dB for the GÖSA to obtain 50% speech recognition compared to native listeners. Conclusions: In clinical audiology, SRT measurements with a closed-set speech test (i.e. DTT for screening or OLSA test for clinical purposes) should be used with non-native listeners rather than open-set speech tests (such as the GÖSA or HINT), especially if a closed-set version in the patient's own native language is available.     

Adaptation of the HINT (hearing in noise test) for adult Canadian Francophone populations

The HINT provides an efficient and reliable method of assessing speech intelligibility in quiet and in noise by using an adaptive strategy to measure speech reception thresholds for sentences, thus avoiding ceiling and floor effects that plague traditional measures performed at fixed presentation levels A strong need for such a test within the Canadian Francophone population, led us to develop a French version of the HINT. Here we describe the development of this test. The Canadian French version is composed of 240-recorded sentences, equated for intelligibility, and cast into 12 phonemically balanced 20-sentence lists. Average headphone SRTs, measured with 36 adult Canadian Francophone native speakers with normal hearing, were 16.4 dBA in quiet, -3.0 dBA SNR in a 65 dBA noise front condition and -11.4 dBA SNR in a 65 dBA noise side condition. Reliability was established by means of within-subjects standard deviation of repeated SRT measurements over different lists and yielded values of 2.2 and 1.1 dB for the quiet and noise conditions, respectively.     

Adaptation of the HINT (hearing in noise test) for adult Canadian Francophone populations

The HINT provides an efficient and reliable method of assessing speech intelligibility in quiet and in noise by using an adaptive strategy to measure speech reception thresholds for sentences, thus avoiding ceiling and floor effects that plague traditional measures performed at fixed presentation levels. A strong need for such a test within the Canadian Francophone population, led us to develop a French version of the HINT. Here we describe the development of this test. The Canadian French version is composed of 240-recorded sentences, equated for intelligibility, and cast into 12 phonemically balanced 20-sentence lists. Average headphone SRTs, measured with 36 adult Canadian Francophone native speakers with normal hearing, were 16.4?dBA in quiet, ?3.0?dBA SNR in a 65?dBA noise front condition and ?11.4?dBA SNR in a 65?dBA noise side condition. Reliability was established by means of within-subjects standard deviation of repeated SRT measurements over different lists and yielded values of 2.2 and 1.1?dB for the quiet and noise conditions, respectively.     

Talker- and language-specific effects on speech intelligibility in noise assessed with bilingual talkers: Which language is more robust against noise and reverberation?

Objective: Investigate talker- and language-specific aspects of speech intelligibility in noise and reverberation using highly comparable matrix sentence tests across languages. Design: Matrix sentences spoken by German/Russian and German/Spanish bilingual talkers were recorded. These sentences were used to measure speech reception thresholds (SRTs) with native listeners in the respective languages in different listening conditions (stationary and fluctuating noise, multi-talker babble, reverberated speech-in-noise condition). Study sample: Four German/Russian and four German/Spanish bilingual talkers; 20 native German-speaking, 10 native Russian-speaking, and 10 native Spanish-speaking listeners. Results: Across-talker SRT differences of up to 6 dB were found for both groups of bilinguals. SRTs of German/Russian bilingual talkers were the same in both languages. SRTs of German/Spanish bilingual talkers were higher when they talked in Spanish than when they talked in German. The benefit from listening in the gaps was similar across all languages. The detrimental effect of reverberation was larger for Spanish than for German and Russian. Conclusions: Within the limitations set by the number and slight accentedness of talkers and other possible confounding factors, talker- and test-condition-dependent differences were isolated from the language effect: Russian and German exhibited similar intelligibility in noise and reverberation, whereas Spanish was more impaired in these situations.     

Development of the speech test signal in Brazilian Portuguese for real-ear measurement

Abstract

Objective: Recommended practice is to verify the gain and/or output of hearing aids with speech or speech-shaped signals. This study has the purpose of developing a speech test signal in Brazilian Portuguese that is electroacoustically similar to the international long-term average speech spectrum (ILTASS) for use in real ear verification systems. Design: A Brazilian Portuguese speech passage was recorded using standardized equipment and procedures for one female talker and compared to ISTS. The passage consisted of simple, declarative sentences making a total of 148 words. Study sample: The recordings of a Brazilian Portuguese passage were filtered to the ILTASS and compared to the International Speech Test Signal (ISTS). Aided recordings were made at three test levels, for three audiograms for the Brazilian Portuguese passage and the ISTS. Results: The unaided test signals were spectrally matched to within 0.5 dB. Aided evaluation revealed that the Brazilian Portuguese passage produced aided spectra that were within 1 dB on average, within about 2 dB per audiogram, and within about 3 dB per frequency for 95% of fittings. Conclusion: Results indicate that the Brazilian Portuguese passage developed in this study provides similar electroacoustic hearing-aid evaluations to those expected from the standard ISTS passage.