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.     

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.     

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.     

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.     

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.     

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.     

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.     

Adaptation of the STARR test for adult Italian population: A speech test for a realistic estimate in real-life listening conditions

Objectives: To introduce the Italian adaptation of the STARR test based on a roving-level adaptive method to mimic challenging real-life listening conditions for use in people with auditory prostheses. Design: Normative data were collected and interlist-variability, as well as learning effects, were investigated using a within-subject design with repeated measures. Study sample: A group of 32 normal-hearing (NH) adults participated in the study. Results: The average speech reception threshold (SRT) for NH subjects was??8.4 dB SNR. The variability of mean SRTs across test lists was relatively small (≤1 dB for all test lists). The statistically significant differences between lists were eliminated after applying correction factors. On the basis of variability for the corrected SRTs within each subject, a difference of 2.8 dB in SRT was meaningful for outcome comparisons using one test list per condition and 2 dB using two lists per condition. Statistical analysis did not show any significant learning effects. Conclusions: Findings in NH listeners suggested that the Italian STARR test could be a promising supplement to existing speech assessment tools. Further studies in populations with hearing impairment could contribute to cross-language studies.     

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.     

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.     

Performance on a Spanish picture-identification task using a multimedia format

An option for estimating the word-recognition performance of patients who do not speak English as a first language involves using auditory materials, presented in the patient's native language, in conjunction with a closed-set response mode incorporating pictures or written words. The advantage of this auditory/visual paradigm is that the audiologist is not required to know the foreign language and is therefore not required to judge the accuracy of an oral response to speech stimuli in a foreign language. Spanish auditory/visual materials, known as the Spanish Picture-Identification Task, were developed to be used in a computer-driven multimedia administration and scoring format. Performance data, both in open- (word-recognition) and closed-set (word-identification) response modes, were established for the Spanish Picture-Identification Task using subjects whose first language was Spanish. The results from the open-set paradigm indicate that the Spanish Picture-Identification Task word lists are essentially equivalent to conventional Spanish and English materials used for word recognition. Findings from the closed-set conditions indicate that the Spanish Picture-Identification Task materials are appropriate for estimating the word-identification abilities of Spanish-speaking adult listeners.     

Internationally comparable screening tests for listening in noise in several European languages: The German digit triplet test as an optimization prototype

Abstract

Objective: A review is given of internationally comparable speech-in-noise tests for hearing screening purposes that were part of the European HearCom project. This report describes the development, optimization, and evaluation of such tests for headphone and telephone presentation, using the example of the German digit triplet test. In order to achieve the highest possible comparability, language- and speaker-dependent factors in speech intelligibility should be compensated for. Materials and methods: The tests comprise spoken numbers in background noise and estimate the speech reception threshold (SRT), i.e. the signal-to-noise ratio (SNR) yielding 50% speech intelligibility. Results: The respective reference speech intelligibility functions for headphone and telephone presentation of the German version for 15 and 10 normal-hearing listeners are described by a SRT of ?9.3?±?0.2 and ?6.5?±?0.4 dB SNR, and slopes of 19.6 and 17.9%/dB, respectively. Reference speech intelligibility functions of all digit triplet tests optimized within the HearCom project allow for investigation of the comparability due to language specificities. Conclusions: The optimization criteria established here should be used for similar screening tests in other languages.     

Laboratory evaluation of an optimised internet-based speech-in-noise test for occupational high-frequency hearing loss screening: Occupational Earcheck

Objective: The “Occupational Earcheck” (OEC) is a Dutch online self-screening speech-in-noise test developed for the detection of occupational high-frequency hearing loss (HFHL). This study evaluates an optimised version of the test and determines the most appropriate masking noise. Design: The original OEC was improved by homogenisation of the speech material, and shortening the test. A laboratory-based cross-sectional study was performed in which the optimised OEC in five alternative masking noise conditions was evaluated. Study sample: The study was conducted on 18 normal-hearing (NH) adults, and 15 middle-aged listeners with HFHL. Results: The OEC in a low-pass (LP) filtered stationary background noise (test version LP 3: with a cut-off frequency of 1.6?kHz, and a noise floor of ?12?dB) was the most accurate version tested. The test showed a reasonable sensitivity (93%), and specificity (94%) and test reliability (intra-class correlation coefficient: 0.84, mean within-subject standard deviation: 1.5?dB SNR, slope of psychometric function: 13.1%/dB SNR). Conclusions: The improved OEC, with homogenous word material in a LP filtered noise, appears to be suitable for the discrimination between younger NH listeners and older listeners with HFHL. The appropriateness of the OEC for screening purposes in an occupational setting will be studied further.     

Speech perception in noise for bilingual listeners with normal hearing

Objective: The purpose of this study was to determine if speech-in-noise ability, as measured by SNR-50 and SNR loss in bilingual Spanish listeners with normal hearing, was affected by test difficulty. Design: Quasi-experimental, non-randomized intervention study. Study sample: Two groups of adult listeners participated: monolingual English listeners with normal hearing (N?=?12) and bilingual Spanish listeners with normal hearing who were proficient in English (N?=?10). The quick speech-in-noise (QuickSIN), the Bamford-Kowal-Bench speech-in-noise (BKB-SIN), and the words-in-noise (WIN) tests were used to assess signal-to-noise ratio (SNR) loss and SNR-50 for both groups. Results: Despite the fact that the bilinguals had normal hearing and were proficient in English, each of the speech-in-noise tests evaluated indicated the Spanish listeners had measurable SNR loss and higher than normal SNR-50s. Performance on the BKB-SIN was best for both groups, indicating test difficulty had a significant impact on speech perception in noise. Conclusions: Bilingual Spanish listeners with normal hearing exhibited a mild SNR loss comparable to that observed for a person with hearing loss. This decreased performance in noise requires an improved SNR for this population to reach a comparable level of comprehension to their monolingual English counterparts.     

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.     

The Sharvard Corpus: A phonemically-balanced Spanish sentence resource for audiology

Abstract

Objective: The current study describes the collection of a new phonemically-balanced Spanish sentence resource, known as the Sharvard Corpus. Design: The resource contains 700 sentences inspired by the original English Harvard sentences along with speech recordings from a male and female native peninsular Spanish talker. Sentences each contain five keywords for scoring and are grouped into 70 lists of 10 sentences using an automatic phoneme-balancing procedure. Study sample: Twenty-three native Spanish listeners identified keywords in the Sharvard sentences in speech-shaped noise. Results: Psychometric functions for the Sharvard sentences indicate mean speech reception thresholds of ? 6.07 and ? 6.24 dB, and slopes of 10.53 and 11.03 percentage points per dB at the 50% keywords correct point for male and female talkers respectively. Conclusions: The resulting open source collection of Spanish sentence material for speech perception testing is available online.     

The influence of lexical-access ability and vocabulary knowledge on measures of speech recognition in noise

Objective: The main objective was to investigate the effect of linguistic abilities (lexical-access ability and vocabulary size) on different measures of speech-in-noise recognition in normal-hearing listeners with various levels of language proficiency. Design: Speech reception thresholds (SRTs) were measured for sentences in steady-state (SRT_stat) and fluctuating noise (SRT_fluc), and for digit-triplets in steady-state noise (DIN). Lexical-access ability was measured with a lexical-decision test and a word-naming test. Vocabulary size was also measured. For the SRT, keyword scoring and sentence scoring were compared. Study sample: To introduce variation in linguistic abilities, three groups of 24 young normal-hearing listeners were included: higher-educated native, lower-educated native, and higher-educated non-native listeners. Results: Lexical-access ability was most accurately measured with combined results of lexical decision and word naming. Lexical-access ability explained 60% of the variance in SRT. The effect of linguistic abilities on SRTs was up to 5.6 dB for SRT_stat and 8 dB for SRT_fluc. Using keyword scoring reduced this effect by approximately 1.5 dB. For DIN the effect of linguistic ability was less than 1 dB. Conclusions: Lexical-access ability is an important predictor of SRTs in normal-hearing listeners. These results are important to consider in the interpretation of speech-in-noise scores of hearing-impaired listeners.     

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 multilingual matrix test: Principles,applications, and comparison across languages: A review

Objective: A review of the development, evaluation, and application of the so-called ‘matrix sentence test’ for speech intelligibility testing in a multilingual society is provided. The format allows for repeated use with the same patient in her or his native language even if the experimenter does not understand the language. Design: Using a closed-set format, the syntactically fixed, semantically unpredictable sentences (e.g. ‘Peter bought eight white ships’) provide a vocabulary of 50 words (10 alternatives for each position in the sentence). The principles (i.e. construction, optimization, evaluation, and validation) for 14 different languages are reviewed. Studies of the influence of talker, language, noise, the training effect, open vs. closed conduct of the test, and the subjects’ language proficiency are reported and application examples are discussed. Results: The optimization principles result in a steep intelligibility function and a high homogeneity of the speech materials presented and test lists employed, yielding a high efficiency and excellent comparability across languages. The characteristics of speakers generally dominate the differences across languages. Conclusion: The matrix test format with the principles outlined here is recommended for producing efficient, reliable, and comparable speech reception thresholds across different languages.