Open-fitting hearing aids: a comparative analysis between open behind-the-ear and open completely-in-the-canal instant-fit devices.

PURPOSE: Our study aims to assess the open-fitting capabilities and vent properties of traditional open-fitting behind-the-ear (open BTE) hearing aids to instant-fit open-fitting completely-in-the-canal (open CIC) systems. METHODS: The study analysed data from 40 patients grouped in two groups based on the used hearing aids. Free field pure tone and speech audiometry were performed to obtain the free-field pure tone average and free-field word recognition score (WRS). The matrix sentence test was employed to evaluate the auditory performance and functional outcomes of patients. The Satisfaction with Amplification in Daily Life (SADL) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire were used to assess the personal satisfaction and benefit provided by the hearing aid. Real ear measurements were conducted to objectively evaluate the Real-Ear Unaided Gain (REUG) and Real-Ear Occluded Gain (REOG) of the two groups. For this purpose, six frequency bands (band 1 from 125 to 200 Hz, band 2 from 250 to 400 Hz, band 3 from 500 to 800 Hz, band 4 from 1000 to 1600 Hz, band 5 from 2000 to 3150 Hz, and band 6 from 4000 to 6300 Hz) were defined and compared. RESULTS: Free-field WRS exhibited a significant difference (p-value = 0.004) between open BTE and open CIC, with better results for the open BTE. Matrix test speech reception threshold scores did not differ significantly between groups. No statistical significant difference were observed between APHAB and SADL total scores. Correlation tests revealed a negative correlation between SRT and APHAB scores in the open BTE group, not seen in the open CIC. No statistically significant difference was observed for all bands of REUG values, demonstrating comparability in terms of acoustic resonance of the external auditory canal. Comparing the REOG recorded in the two groups a significant difference was observed for bands 2 through 6. While the average REOG values for bands 5 and 6 were higher in patients with traditional open BTE aids, in contrast, for bands 2, 3, and 4, the REOG values for the open CIC group were higher and statistically significant compared to patients wearing traditional open-fitting BTE hearing aids. CONCLUSION: Patients with open CIC seem to perform worse in quiet environments compared to noisy ones, as indicated by the free field WRS score. However, the absence of differences in functional performance assessed with the matrix sentence test, and in the psychosocial aspects, makes these devices a good solution for individuals who reject hearing aids due to aesthetic concerns. The differences in terms of real ear measurements, while statistically significant, do not negatively impact overall performance.

Functional outcomes for speech-in-noise intelligibility of NAL-NL2 and DSL v.5 prescriptive fitting rules in hearing aid users.

PURPOSE: The primary aim of this research study is to assess whether differences exist in the application of the NAL-NL2 and DSL v.5 prescription formulas in terms of speech-in-noise intelligibility. METHODS: Data from 43 patients, were retrospectively evaluated and analyzed. Inclusion criteria were patients with bilateral conductive, sensorineural, or mixed hearing loss, already using hearing aids for at least 1 year, and aged 18 years or older. Patients were categorized into two groups based on the prescriptive method employed by the hearing aid: NAL-NL2 or DSL v.5. Pure tone audiometry, speech audiometry, free field pure tone and speech audiometry with the hearing aid, and Matrix sentence test were performed. The Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire was used to assess the personal audiological benefit provided by the hearing aid. RESULTS: No statistically significant differences were found comparing the free-field pure tone average (FF PTA) and the free-field Word Recognition Score (FF WRS). Comparing the Speech Reception Threshold (SRT) parameter of patients with NAL-NL2 vs DSL v.5, no statistically significant difference was found, thus highlighting a condition of comparability between the two prescription methods in terms of speech-in-noise intelligibility. Comparing the results of the APHAB questionnaire, no statistically significant differences were evident for all subscales and overall benefit. When conducting a comparison between male and female patients using the NAL-NL2 method, no differences were observed in SRT values, however, the APHAB questionnaire revealed a difference in the AV subscale score for the same subjects. CONCLUSION: Our analysis revealed no statistically significant differences in speech-in-noise intelligibility, as measured by the SRT values from the Matrix Sentence Test, when comparing the two prescriptive methods. This compelling result reinforces the notion that, functionally, both methods are comparably effective in enhancing speech intelligibility in real-world, noisy environments. However, it is crucial to underscore that the absence of differences does not diminish the importance of considering individual patient needs and preferences in the selection of a prescriptive method.

Age standardization and time-of-day performance for the Oldenburg Sentence Test (OLSA): results from the population-based Gutenberg Health Study.

PURPOSE: The Oldenburg Sentence Test (OLSA) is a German matrix test designed to determine speech recognition thresholds (SRT). It is widely used for hearing-aids and cochlear implant fitting, but an age-adjusted standard is still lacking. In addition, knowing that the ability to concentrate is an important factor in OLSA performance, we hypothesized that OLSA performance would depend on the time of day it was administered. The aim of this study was to propose an age standardization for the OLSA and to determine its diurnal performance. METHODS: The Gutenberg Health Study is an ongoing population-based study and designed as a single-centre observational, prospective cohort study. Participants were interviewed about common otologic symptoms and tested with pure-tone audiometry and OLSA. Two groups-subjects with and without hearing loss-were established. The OLSA was performed in two runs. The SRT was evaluated for each participant. Results were characterized by age in 5-year cohorts, gender and speech recognition threshold (SRT). A time stamp with an hourly interval was also implemented. RESULTS: The mean OLSA SRT was - 6.9 ± 1.0 dB (group 1 male) and - 7.1 ± 0.8 dB (group 1 female) showing an inverse relationship with age in the whole cohort, whereas a linear increase was observed in those without hearing loss. OLSA-SRT values increased more in males than in females with increasing age. No statistical significance was found for the diurnal performance. CONCLUSIONS: A study with 2900 evaluable Oldenburg Sentence Tests is a novelty and representative for the population of Mainz and its surroundings. We postulate an age- and gender-standardized scale for the evaluation of the OLSA. In fact, with an intergroup standard deviation (of about 1.5 dB) compared to the age dependence of 0.7 dB/10 years, this age normalization should be considered as clinically relevant.

Benefits of bone conduction hearing aid in children with unilateral aural atresia.

Objective: To assess the hearing benefit with a unilateral bone conduction hearing aid in a cohort of children with unilateral aural atresia. Methods: Cross-sectional case series pilot study involving 7 children (median age: 10 years, range 6-11). All patients underwent pure-tone, speech, aided sound field and aided speech audiometry and Simplified Italian Matrix Test (SIMT) with and without bone conduction hearing aid (Baha 5® CochlearTM). Cognitive abilities were assessed in 5 patients. Results: The mean air conduction pure-tone average (PTA) of the atretic ear was 63.2 ± 6.9 dB, while the bone conduction PTA was 12.6 ± 4.7 dB. Speech discrimination score of the atretic ear was 88.6 ± 3.8 dB, while with the hearing aid it was 52.8 ± 1.9 dB. In the contralateral ear, there was no significant air-bone gap, and PTAs for air and bone conduction thresholds were within normal range (PTA ≤ 25 dB). The mean aided air conduction hearing threshold was 26.2 ± 7.97. Mean speech recognition threshold without the hearing aid was -5.1 ± 1.9 dB, and -6.0 ± 1.7 dB with the hearing aid tested with the SIMT. The mean score of the cognitive test was 46.8 ± 42.8. Conclusions: These preliminary findings should encourage clinicians in proposing a unilateral bone conduction hearing aid in children with unilateral atresia.

Development and evaluation of the Cantonese matrix sentence test.

OBJECTIVE: To develop the Cantonese matrix (YUEmatrix) test according to the international standard procedure and examine possible different outcomes in another tonal language. DESIGN: A 50-word Cantonese base-matrix was established. Word-specific speech recognition functions, speech recognition thresholds (SRT), and slopes were obtained. The speech material was homogenised in intelligibility by applying level corrections up to ± 3 dB. Subsequently, the YUEmatrix test was evaluated in five aspects: training effect, test-list equivalence, test-retest reliability, establishment of reference data for normal-hearing Cantonese-speakers, and comparison with the Cantonese-Hearing-In-Noise-Test. STUDY SAMPLE: Overall, 64 normal-hearing native Cantonese-speaking listeners. RESULTS: SRT measurements with adaptive procedures resulted in a reference SRT of -9.7 ± 0.7 dB SNR for open-set and -11.1 ± 1.2 dB SNR for the closed-set response format. Fixed SNR measurements suggested a test-specific speech intelligibility function slope of 15.5 ± 0.7%/dB. Seventeen 10-sentences base test lists were confirmed to be equivalent with respect to speech intelligibility. Training effect was not observed after two measurements of 20-sentences lists. CONCLUSIONS: The YUEmatrix yields comparable results to matrix tests in other languages including Mandarin. Level adjustments to homogenise sentences appear to be less effective for tonal languages than for most other languages developed so far.

Development of speech intelligibility in geriatric individuals with hearing loss.

BACKGROUND: In our study, we aimed to evaluate the hearing aid benefit and speech intelligibility with hearing aids using objective and subjective measurements, according to the type of hearing loss in elderly individuals who used different types of hearing aids. METHODS: The objective and subjective findings from a total of 47 elderly individuals between the ages of 60 and 84, who used regular hearing aids for at least six months, and who were diagnosed with different types and degrees of hearing loss were evaluated by scanning them retrospectively. RESULTS: : In our study, the Adaptive Turkish matrix sentence test (ATMST) was carried out with binaural headphones, and a statistically significant difference was observed between the ATMST scores of individuals with symmetrical hearing loss. A significant difference was found between the ATMST score averages for individuals with symmetrical hearing loss (S0 N90 and S0 N270) and asymmetric hearing loss (S0 N0 and S0 N270) in the free area. A significant difference was found between abbreviated profile of hearing aid benefit satisfaction questionnaires before and after hearing aid use in all groups. DISCUSSION: The Turkish matrix sentence test (TMST) in noise can be used routinely in clinics in order to evaluate the possible hearing loss from the daily environment and the hearing aid effectiveness.

Neuropsychiatric and sleep study in autosomal dominant dopa-responsive dystonia.

Introduction: Although the diurnal fluctuation of motor dysfunction, reversible with small doses of dopamine, is a cornerstone for the phenotype of the autosomal dominant Segawa syndrome, the non-motor symptoms of this neurotransmitter deficiency have still received limited attention. Objective: This study aims to evaluate non-motor symptoms of this dopa-responsive dystonia through an intrafamilial comparative cross-sectional study. Methods: Seventeen individuals with a c.IVS5 + 3insT (c.626 + 3insT) variation in the GTP cyclohydrolase-1 gene (GCH1, HGNC: 4193) and 34 intrafamilial controls were studied using the Beck Depression Inventory-II, the Wiener Matrizen Test 2, the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the MINI/MINI PLUS Questionnaires, the World Health Organization Quality of Life - BREF Instrument and a drug use assessment questionnaire. Results: No significant difference was found between the groups in the prevalence of sleep disorders and in cognitive function. Nevertheless, generalized anxiety disorder (p = 0.050) and attention-deficit/hyperactivity disorder in childhood (p = 0.011) were observed only in individuals without the molecular variation. The group with the GCH1 variation presented a worse perception about how safe they feel in their daily lives (p = 0.034), less satisfaction with themselves (p = 0.049) and with their relationships (p = 0.029), and a higher prevalence of past major depressive episodes before use of L-Dopa (p = 0.046). Conclusion: Low dopamine could have been protective against generalized anxiety disorder and attention-deficit/hyperactivity disorder in childhood in Segawa group individuals. The prevalence of depression was higher in individuals with the molecular variant prior to the L-Dopa treatment. Considering it, the penetrance estimates for the variant carriers increased from 58.8% to up to 88% in this large studied family. Additionally, neuropsychiatric tests of all individuals with a molecular diagnosis in an affected family are a valuable instrument for its clinical management.

Power output and hearing performance in osseointegrated auditory devices.

BACKGROUND AND OBJECTIVE: Osseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve. MATERIALS Y METHODS: 44 patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient. The direct bone conduction thresholds and the power output values from the processors were also obtained. RESULTS: The pure tone average threshold in free field was 39.29 dB (SD = 9.15), so that the mean gain was 29.18 dB (SD = 10.13) with the device. This involved an air-bone gap closure in 63.64% of patients. The pure tone average threshold in direct bone conduction was 27.6 dB (SD = 10.91), which was 8.4 dB better than the pure tone average threshold via bone conduction. The mean gain in speech recognition was 39.15% (SD = 23.98) at 40 dB and 36.66% (SD = 26.76) at 60 dB. The mean gain in the signal-to-noise ratio was -5.9 dB (SD = 4.32). On the other hand, the mean power output values were 27.95 dB µN (SD = 6.51) in G40 and 26.22 dB µN (SD = 6.49) in G60. When analysing the relationship between bone conduction thresholds and G40 and G60 values, a correlation from the frequency of 1000 Hz was observed. However, no statistically significant association between power output, functional gain or speech recognition gain was found. CONCLUSIONS: The osseointegrated auditory devices generate hearing improvement in tonal thresholds and speech recognition, even in noise. Most patients closed the air-bone gap with the device. There is a direct relationship between the bone conduction threshold and the power output values from the processor, but only in mid and high frequencies. However, the relationship between power output and gain in speech recognition is weaker. Further investigation of contributing factors is necessary.

Power output and hearing performance in osseointegrated auditory devices. / Análisis de la potencia de salida y del rendimiento auditivo de los dispositivos auditivos osteointegrados.

BACKGROUND AND OBJECTIVE: Osseointegrated auditory devices are hearing gadgets that use the bone conduction of sound to produce hearing improvement. The mechanisms and factors that contribute to this sound transmission have been widely studied, however, there are other aspects that remain unknown, for instance, the influence of the processor power output. The aim of this study was to know if there is any relationship between the power output created by the devices and the hearing improvement that they achieve. MATERIALS AND METHODS: Forty-four patients were implanted with a percutaneous Baha® 5 model. Hearing thresholds in pure tone audiometry, free-field audiometry, and speech recognition (in quiet and in noise) were measured pre and postoperatively in each patient .The direct bone conduction thresholds and the power output values from the processors were also obtained. RESULTS: The pure tone average threshold in free field was 39.29dB (SD 9.15), so that the mean gain was 29.18dB (SD 10.13) with the device. This involved an air-bone gap closure in 63.64% of patients. The pure tone average threshold in direct bone conduction was 27.6dB (SD 10.91), which was 8.4dB better than the pure tone average threshold via bone conduction. The mean gain in speech recognition was 39.15% (SD 23.98) at 40dB and 36.66% (SD 26.76) at 60dB. The mean gain in the signal-to-noise ratio was -5.9dB (SD 4.32). On the other hand, the mean power output values were 27.95dB µN (SD 6.51) in G40 and 26.22dB µN (SD 6.49) in G60. When analysing the relationship between bone conduction thresholds and G40 and G60 values, a correlation from the frequency of 1,000Hz was observed. However, no statistically significant association between power output, functional gain or speech recognition gain was found. CONCLUSIONS: The osseointegrated auditory devices generate hearing improvement in tonal thresholds and speech recognition, even in noise. Most patients closed the air-bone gap with the device. There is a direct relationship between the bone conduction threshold and the power output values from the processor, but only in mid and high frequencies. However, the relationship between power output and gain in speech recognition is weaker. Further investigation of contributing factors is necessary.

Clinical validation of the Russian Matrix test - effect of hearing loss, age, and noise level.

OBJECTIVE: To validate the Russian matrix sentence test (RUMatrix) for the assessment of speech recognition in quiet and in noise in clinical praxis. The effect of hearing impairment, age, and masking-noise level on speech recognition was examined. DESIGN: All participants underwent pure tone audiometry, a monosyllabic speech test in quiet, and speech recognition measurements with RUMatrix in quiet (SRTQ) and in noise (SRTN). STUDY SAMPLE: One hundred and forty-two listeners divided into four groups: 1. Young normal-hearing listeners, 2. Older normal-hearing listeners, 3. Young hearing-impaired listeners, and 4. Older hearing-impaired listeners. RESULTS: Significant differences between groups of listeners were found in the SRTQ and SRTN. A strong correlation between hearing threshold and SRTQ (R2=0.88, p < 0.001) indicates a strong link between speech recognition in quiet and audibility. The pure-tone average explained less variance in SRTN (R2=0.67, p < 0.001), pointing out an additional influence of suprathreshold distortion. A high test sensitivity of 0.99 was found for SRTN and SRTQ. The monosyllabic test had a low sensitivity (0.21), indicating that the test is not suitable for separating normal-hearing and hearing-impaired listeners. CONCLUSIONS: RuMatrix is a reliable speech recognition assessment tool with a high sensitivity and validity for the main aspects of hearing impairment.

[Application of the matrix sentence test Russian version in children]. / Primenenie russkoiazychnoi versii matriksnogo frazovogo testa u detei.

The Russian version of the matrix sentence test (RUMatrix test) has been shown to be suitable for accurate assessment of speech intelligibility in adults. AIM: To approve the RUMatrix for measurements in children and to evaluate its simplified version (Simplified RUMatrix). MATERIAL AND METHODS: 20 normal-hearing adults and 81 normal-hearing children aged from 5 to 10 years were involved into the study. Both versions of the test were developed by the University of Oldenburg, Germany. The tests contain syntactically homogeneous, semantically unpredictable sentences/phrases presented under the background noise. Each test list is composed of 20 sentences of 5 words for RUMatrix and of 14 speech phrases of 3 words for Simplified RUMatrix. RESULTS: A limitation in the use of the RUMatrix test in children under 10 years of age has been revealed. Evaluation of Simplified RUMatrix test in adults confirmed the perceptual homogeneity of the test list. The results of the RUMatrix test and the Simplified RUMatrix test in children were lower than in adults; they were improving with age and reach adult values by 10 years. One training track of Simplified RUMatrix test should be carried out before the assessment. CONCLUSION: The RUMatrix can be used for children of 10 years and older. The normative data of Simplified RUMatrix both for adults and children of the different ages have been obtained.

IQ estimation by means of EEG-fNIRS recordings during a logical-mathematical intelligence test.

Intelligence differences of individuals are attributed to the structural and functional differences of the brain. Neural processing operations of the human brain vary according to the difficulty level of the problem and the intelligence level of individuals. In this study, we used a bimodal system consisting of functional Near-Infrared Spectroscopy (fNIRS) and Electroencephalogram (EEG) to investigate these inter-individual differences. A continuous wave 32-channel fNIRS from OxyMonfNIRS device (Artinis) and 19-channel EEG from (g.tec's company) were utilized to study the oxygenation procedure as well as the electrical activity of the brain when doing the problems of Raven's Progressive Matrix (RPM) intelligence test. We used this information to estimate the Intelligence Quotient (IQ) of the individual without performing a complete logical-mathematical intelligence test in a long-time period and examining the answers of people to the questions. After EEG preprocessing, different features including Higuchi's fractal dimension, Shannon entropy values from wavelet transform coefficients, and average power of frequency sub-bands were extracted. Clean fNIRS signals were also used to compute features such as slope, mean, variance, kurtosis, skewness, and peak. Then dimension reduction algorithms such as Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) were applied to select an effective feature set from fNIRS and EEG in order to improve the IQ estimation process. We utilized two regression methods, i.e., Linear Regression (LR) and Support Vector Regression (SVR), to extract optimum models for the IQ determination. The best regression models based on fNIRS-EEG and fNIRS presented 3.093% and 3.690% relative error for 11 subjects, respectively.

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

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.

Development and evaluation of a mixed gender, multi-talker matrix sentence test in Australian English.

OBJECTIVE: To develop, in Australian English, the first mixed-gender, multi-talker matrix sentence test. DESIGN: Speech material consisted of a 50-word base matrix whose elements can be combined to form sentences of identical syntax but unpredictable content. Ten voices (five female and five male) were recorded for editing and preliminary level equalization. Elements were presented as single-talker sentences-in-noise during two perceptual tests: an optimization phase that provided the basis for further level correction, and an evaluation phase that perceptually validated those changes. STUDY SAMPLE: Ten listeners participated in the optimization phase; these and an additional 32 naïve listeners completed the evaluation test. All were fluent in English and all but one had lived in Australia for >2 years. RESULTS: Optimization reduced the standard deviation (SD) and speech reception threshold (SRT) range across all speech material (grand mean SRT = -10.6 dB signal-to-noise ratio, median = -10.8, SD =1.4, range =13.7, slope =19.3%/dB), yielding data consistent with cross-validated matrix tests in other languages. Intelligibility differences between experienced and naïve listeners were minimal. CONCLUSIONS: The Australian matrix corpus provides a robust set of test materials suitable for both clinical assessment and research into the dynamics of active listening in multi-talker environments.

Assessment of the Speech Intelligibility Performance of Post Lingual Cochlear Implant Users at Different Signal-to-Noise Ratios Using the Turkish Matrix Test.

BACKGROUND: Spoken word recognition and speech perception tests in quiet are being used as a routine in assessment of the benefit which children and adult cochlear implant users receive from their devices. Cochlear implant users generally demonstrate high level performances in these test materials as they are able to achieve high level speech perception ability in quiet situations. Although these test materials provide valuable information regarding Cochlear Implant (CI) users' performances in optimal listening conditions, they do not give realistic information regarding performances in adverse listening conditions, which is the case in the everyday environment. AIMS: The aim of this study was to assess the speech intelligibility performance of post lingual CI users in the presence of noise at different signal-to-noise ratio with the Matrix Test developed for Turkish language. STUDY DESIGN: Cross-sectional study. METHODS: The thirty post lingual implant user adult subjects, who had been using implants for a minimum of one year, were evaluated with Turkish Matrix test. Subjects' speech intelligibility was measured using the adaptive and non-adaptive Matrix Test in quiet and noisy environments. RESULTS: The results of the study show a correlation between Pure Tone Average (PTA) values of the subjects and Matrix test Speech Reception Threshold (SRT) values in the quiet. Hence, it is possible to asses PTA values of CI users using the Matrix Test also. However, no correlations were found between Matrix SRT values in the quiet and Matrix SRT values in noise. Similarly, the correlation between PTA values and intelligibility scores in noise was also not significant. Therefore, it may not be possible to assess the intelligibility performance of CI users using test batteries performed in quiet conditions. CONCLUSION: The Matrix Test can be used to assess the benefit of CI users from their systems in everyday life, since it is possible to perform intelligibility test with the Matrix test using a material that CI users experience in their everyday life and it is possible to assess their difficulty in speech discrimination in noisy conditions they have to cope with.

Matrix sentence intelligibility prediction using an automatic speech recognition system.

OBJECTIVE: The feasibility of predicting the outcome of the German matrix sentence test for different types of stationary background noise using an automatic speech recognition (ASR) system was studied. DESIGN: Speech reception thresholds (SRT) of 50% intelligibility were predicted in seven noise conditions. The ASR system used Mel-frequency cepstral coefficients as a front-end and employed whole-word Hidden Markov models on the back-end side. The ASR system was trained and tested with noisy matrix sentences on a broad range of signal-to-noise ratios. STUDY SAMPLE: The ASR-based predictions were compared to data from the literature ( Hochmuth et al, 2015 ) obtained with 10 native German listeners with normal hearing and predictions of the speech intelligibility index (SII). RESULTS: The ASR-based predictions showed a high and significant correlation (R² = 0.95, p < 0.001) with the empirical data across different noise conditions, outperforming the SII-based predictions which showed no correlation with the empirical data (R² = 0.00, p = 0.987). CONCLUSIONS: The SRTs for the German matrix test for listeners with normal hearing in different stationary noise conditions could well be predicted based on the acoustical properties of the speech and noise signals. Minimum assumptions were made about human speech processing already incorporated in a reference-free ordinary ASR system.

Optimization of the Dutch matrix test by random selection of sentences from a preselected subset.

Matrix tests are available for speech recognition testing in many languages. For an accurate measurement, a steep psychometric function of the speech materials is required. For existing tests, it would be beneficial if it were possible to further optimize the available materials by increasing the function's steepness. The objective is to show if the steepness of the psychometric function of an existing matrix test can be increased by selecting a homogeneous subset of recordings with the steepest sentence-based psychometric functions. We took data from a previous multicenter evaluation of the Dutch matrix test (45 normal-hearing listeners). Based on half of the data set, first the sentences (140 out of 311) with a similar speech reception threshold and with the steepest psychometric function (≥9.7%/dB) were selected. Subsequently, the steepness of the psychometric function for this selection was calculated from the remaining (unused) second half of the data set. The calculation showed that the slope increased from 10.2%/dB to 13.7%/dB. The resulting subset did not allow the construction of enough balanced test lists. Therefore, the measurement procedure was changed to randomly select the sentences during testing. Random selection may interfere with a representative occurrence of phonemes. However, in our material, the median phonemic occurrence remained close to that of the original test. This finding indicates that phonemic occurrence is not a critical factor. The work highlights the possibility that existing speech tests might be improved by selecting sentences with a steep psychometric function.

Investigation into the applicability and optimization of the Dutch matrix sentence test for use with cochlear implant users.

OBJECTIVE: Matrix sentence tests use words from a fixed word matrix to compose syntactically equivalent, but semantically unpredictable sentences. These tests are suitable for monitoring performance of cochlear implant (CI) users by repeated speech intelligibility testing. This study evaluates the Dutch matrix sentence test in CI users in quiet and in noise. It then investigates the possibility to improve the test-retest reliability for CI users by selecting subsets of sentences. DESIGN: Repeated speech intelligibility testing was performed in quiet and in noise. The effect of sentence selection on the test-retest reliability was predicted by computer simulations and experimentally evaluated using a cross-over design. STUDY SAMPLE: Fifteen post-lingually deafened CI users, of which eleven participated in the cross-over study. RESULTS: The test-retest reliability equaled 2.3 dB in quiet and 1.3 dB in noise. The simulations predicted an improvement in test-retest reliability, especially in quiet. The cross-over study did not confirm the predictions. CONCLUSIONS: The results of the study suggest that the homogeneity of the sentences is not the prime component underlying the test-retest reliability. The Dutch matrix speech material and the selected subsets of sentences were equally suitable for speech intelligibility testing in CI users.

The development and evaluation of the Finnish Matrix Sentence Test for speech intelligibility assessment.

CONCLUSION: The Finnish Matrix Test is the first sentence test in noise for the Finnish language. It was developed according to the HearCom standards and provides reliable speech intelligibility measurements with highly comparable results with the other international matrix tests. OBJECTIVES: The aim of the study was to develop an accurate speech intelligibility test in noise for the Finnish language that is comparable across different languages. METHODS: We chose a matrix sentence test, which comprises a base matrix of 10 names, verbs, numerals, adjectives and nouns. Test lists were formed from this matrix quasi randomly, providing test sentences of the same syntactical structure. The speech material corresponds to everyday spoken language and the phoneme distribution is representative of the Finnish language. The test was optimized by determining the speech recognition thresholds of the individual words and subsequently by applying level corrections of up to ±3 dB. Evaluation measurements were performed to check the equivalence of the different test lists with respect to speech intelligibility and to provide reference values for further clinical applications. RESULTS: After training, the mean speech recognition threshold (SRT) and the slope of the final test lists were -10.1 ± 0.1 dB signal-to-noise-ratio (SNR)and 16.7 ± 1.2%/dB, respectively (measurements at constant level; inter-list variability). The mean SRT and the slope of the test subjects were -10.1 ± 0.7 dB SNR and 17.5 ± 2.2%/dB (measurements at constant level; inter-subject variability). The expected SRT range for normal-hearing young adults for adaptive measurements is -9.7 ± 0.7 dB SNR.

Speech-in-noise tests for multilingual hearing screening and diagnostics1.

PURPOSE: New complementary multilingual speech-in-noise tests in Russian, Turkish, and Spanish for hearing self-screening purposes and follow-up hearing diagnostics are compared to the speech tests of the European project, HearCom (Hearing in the Communication Society). METHOD: The tests consist of spoken numbers (Digit Triplet Test; Smits, Kapteyn, & Houtgast, 2004) or sentences (Matrix Test; e.g., Hagerman, 1982) presented in a background noise and estimate the speech reception threshold, which is the signal-to-noise ratio that yields 50% speech intelligibility. All tests were developed according to the HearCom minimum quality standards for speech intelligibility tests. This report presents a cross-language comparison of reference speech intelligibility functions for monaural headphone measurements with normal-hearing listeners. The same model function was employed to describe the speech intelligibility functions for all of the tests. RESULTS: Reference speech intelligibility functions of the new versions of the Digit Triplet Test and Matrix Test show high comparability to the HearCom tests. In order to achieve the highest possible comparability across languages, language- and speaker-dependent factors in speech intelligibility should be compensated for. CONCLUSION: To date, several complementary tests for screening and diagnostics have been developed in several languages. Adhering to the HearCom standards, the tests are highly comparable across languages. For the Matrix Test, equal syntax and linguistic complexity were maintained across languages due to common methodological standards.