Speech Reception Threshold Test Research Articles

Effects of hearing acuity on psychophysiological responses to effortful speech perception

In recent studies, psychophysiological measures have been used as markers of listening effort, but there is limited research on the effect of hearing loss on such measures. The aim of the current study was to investigate the effect of hearing acuity on physiological responses and subjective measures acquired during different levels of listening demand, and to investigate the relationship between these measures. A total of 125 participants (37 males and 88 females, age range 37-72 years, pure-tone average hearing thresholds at the best ear between -5.0 to 68.8 dB HL and asymmetry between ears between 0.0 and 87.5 dB) completed a listening task. A speech reception threshold (SRT) test was used with target sentences spoken by a female voice masked by male speech. Listening demand was manipulated using three levels of intelligibility: 20% correct speech recognition, 50%, and 80% (IL20%, IL50%, IL80%, respectively). During the task, peak pupil dilation (PPD), heart rate (HR), pre-ejection period (PEP), respiratory sinus arrhythmia (RSA), and skin conductance level (SCL) were measured. For each condition, subjective ratings of effort, performance, difficulty, and tendency to give up were also collected. Linear mixed effects models tested the effect of intelligibility level, hearing acuity, hearing asymmetry, and tinnitus complaints on the physiological reactivity (compared to baseline) and subjective measures. PPD and PEP reactivity showed a non-monotonic relationship with intelligibility level, but no such effects were found for HR, RSA, or SCL reactivity. Participants with worse hearing acuity had lower PPD at all intelligibility levels and showed lower PEP baseline levels. Additionally, PPD and SCL reactivity were lower for participants who reported suffering from tinnitus complaints. For IL80%, but not IL50% or IL20%, participants with worse hearing acuity rated their listening effort to be relatively high compared to participants with better hearing. The reactivity of the different physiological measures were not or only weakly correlated with each other. Together, the results suggest that hearing acuity may be associated with altered sympathetic nervous system (re)activity. Research using psychophysiological measures as markers of listening effort to study the effect of hearing acuity on such measures are best served by the use of the PPD and PEP.

A novel approach for estimating initial sound level for speech reception threshold test.

The speech reception threshold (SRT), synonymous with the speech recognition threshold, denotes the minimum hearing level required for an individual to discern 50% of presented speech material. This threshold is measured independently in each ear with a repetitive up-down adjustment of stimulus level starting from the initial SRT value derived from pure tone thresholds (PTTs), measured via pure-tone audiometry (PTA). However, repetitive adjustments in the test contributes to increased fatigue for both patients and audiologists, compromising the reliability of the hearing tests. Determining the first (initial) sound level closer to the finally determined SRT value, is important to reduce the number of repetitions. The existing method to determine the initial sound level is to average the PTTs called pure tone average (PTAv). We propose a novel method using a machine learning approach to estimate a more optimal initial sound level for the SRT test. Specifically, a convolutional neural network with 1-dimensional filters (1D CNN) was implemented to predict a superior initial level than the conventional methods. Our approach produced a reduction of 37.92% in the difference between the initial stimulus level and the final SRT value. This outcome substantiates that our approach can reduce the repetitions for finding the final SRT, and, as the result, the hearing test time can be reduced.

Italian Fast Speech Reception Threshold Test: A New Method to Investigate Adult Auditory Impairment in Noise.

Purpose of our study was to compare two competing methods of performing bisyllabic word speech audiometry for the detection of the 50% speech reception threshold in noise (SRT50). Classic method is performed submitting multiple word lists at a fixed signal-to-noise ratio. A newer Fast method - Italian Fast Speech Reception Threshold 50 (IFastSRT50) - is performed by means of program software with a single list of bisyllabic words and noise intensity shifting. Means comparison between SRT50 Classic and IFastSRT50 shows a slight significant correlation (r = 0.263; p = 0.044) and a wide significant difference: SRT50 Classic = -2.763 dB (SD = 4.1) and IFastSRT50 = -7.803 dB (SD = 2.1) (p < 0.0001). There is a high difference between the test execution time means (SRT50 Classic = 11 min, IFastSRT50 = 2 min; p < 0.0001). The correlation between test results and execution times was higher for SRT50 Classic than IFastSRT50. IFastSRT50 test is a reliable method to quickly investigate signal-to-noise ratio needed to obtain 50% of recognition scores with bisyllabic words; it allows less execution time than SRT50 Classic method and can avoid patient fatigue and other limitations of different speech discrimination tests in noise as sentences based ones.

Development of Singapore English speech audiometry test materials

Background Speech audiometry is utilised for diagnostic and rehabilitative purposes. Speech audiometry involves materials linguistic in nature. The ideal protocol is to have a tester who is a native or at least a fluent speaker of that language to conduct the test on a native listener. Except for a set of psychometrically equivalent word recordings that have yet to be validated, no other existing speech audiometry materials have been developed in Singapore English. Objective This study aims to develop and validate a local set of phonemically balanced English word lists for use on Singaporeans. Methods The first phase encompassed the development of spondaic and phonemically-balanced monosyllabic word lists for Speech Reception Threshold (SRT) and Word Recognition Score (WRS) testing. The second phase established perceptual equivalence across the monosyllabic word lists. The third phase encompassed the validation of these materials on 72 normal-hearing and hearing-impaired Singaporeans between 21 to 80 years old. Participants were tested with two spondaic and six monosyllabic word lists. Participants’ SRT and WRS values were analysed. Results The mean SRT and pure tone audiometry (PTA) average difference was 5.79 dB. All 43 normal-hearing participants achieved a maximum WRS of 100%, at an average presentation level of 28.1 dB above their PTA average. Test-retest analysis revealed clinically insignificant differences across all word lists. Conclusion The test materials are validated to be suitable for testing on Singaporean English speakers. Normative SRT and WRS data for Singaporeans have also been established.

Cortical deafness as a sequel of recurrent stroke in patient with prosthetic heart valves and atrial fibrillation: a case report

BackgroundCortical deafness is an unusual occurrence caused by injury to the central auditory pathway but not to the hearing organ. This paper reports the first case of cortical deafness as a sequel of recurrent stroke in a patient with prosthetic heart valves and atrial fibrillation in Asia.Case presentationA 40-year-old man with a history of atrial fibrillation and valvular heart disease comes with weakness on the right side of the body and slurred speech. Examination showed hemiplegia with increased d-dimer and activated partial thromboplastin time. (APTT). Brain MRI showed multiple subacute infarctions in the temporal lobe. Diffusion Tensor Imaging (DTI) tractography showed no visible auditory tract. Pure tone audiogram and brainstem auditory evoked potential test was normal, but speech reception threshold test was very poor. The patient has been diagnosed with recurrent ischemic stroke with sequel cortical deafness and received anticoagulant therapy and speech therapy. The patient reported minimal subjective impairment 1 month later with no further neurological deterioration.ConclusionsA multidisciplinary clinical approach is needed in patients with cortical deafness, especially distinguishing it from other central hearing losses.

Can Auditory and Vestibular Findings Differentiate Vestibular Migraine and Meniere's Disease?

Besides evaluating the auditory and vestibular systems of patients with vestibular migraine (VM) and Meniere's disease (MD), this study aimed to examine the clinical overlaps between these two conditions by detailed evaluation of the patient's symptoms. Subjects and. The ears of the patients with VM and MD were evaluated and patients' vestibular and auditory complaints were questioned particularly. Pure tone audiometry, vestibular evoked myogenic potential (VEMP) responses, and caloric test results were evaluated for objective measurements. The VM group had better air-conduction and boneconduction threshold and speech reception threshold and speech discrimination score test values (p<0.05). Regarding the interaural N1-P1 asymmetry ratio, the cervical VEMP between the groups had significant differences (p=0.019). The MD group had more unilateral tinnitus and ear fullness complaints and canal paresis results (p<0.01). The VM group had more motion sickness complaints (p<0.01). If only ears with hearing loss are evaluated; there was no significant difference between VM and MD, but regardless of hearing level or only the patients with normal hearing were evaluated, the VM group had better hearing levels. It should be considered that patients with VM may have VM-independent hearing loss, and patient complaints should be sufficiently detailed to make an accurate distinction from MD.

Prevalence of hearing loss among patients with type 2 diabetes.

The auditory pathway is the main target for high levels of blood sugar. Increased glucose in diabetic patients can disrupt the auditory system physiologically and anatomically. The present study aimed to examine the prevalence of hearing loss in patients with type 2 diabetes. A total of 94 patients with type 2 diabetes, aged from 40 to 80 years, were selected randomly in the present descriptive cross-sectional study for pure tone audiometry (PTA), speech discrimination score (SDS), and speech reception threshold (SRT) tests. Accordingly, patients with a hearing threshold larger than or equal to 25 dB were considered hearing-impaired according to the PTA test. In addition, the patients' speech discrimination score was measured using a list of monosyllabic words with an intensity of 40 dB or more than the SDS test. However, in the SRT test, the patients' superficial speech comprehension threshold was measured using a list of two-syllable words. Most diabetic patients had hearing loss in both right and left ears based on the PTA and SRT tests. However, they did not have hearing loss in both ears according to the SDS test. There was no correlation between the PTA, SRT, and SDS tests and blood creatinine levels in both ears (p>0.05). Nevertheless, the right ear had a positive correlation with systolic blood pressure only in the PTA test (p<0.05). The difference between the two groups of men and women with type 2 diabetes in the hearing level in the right and left ears was not statistically significant. Hearing loss is a common deficiency in diabetic patients. In addition, it seems that diabetes is an independent risk factor for the hearing loss level.

Cochlear implantation in patients with asymmetric hearing loss: reporting and discussing the benefits in speech perception, speech reception threshold, squelch abilities, and patients' reported outcomes.

This study presents the results obtained in a group of patients with asymmetric hearing loss undergoing cochlear implantation at our institution. Prognostic factors are discussed in relation to different rehabilitative approaches for asymmetric hearing loss remediation. The current literature is also discussed. Nineteen adult patients with post-verbal asymmetric hearing loss were enrolled. The results were assessed by means of a speech perception test, completed in silence and with background noise, and a speech reception threshold test (Oldenburg Sentence Test). The subjectively perceived benefits were assessed using the Speech, Spatial and Qualities of Hearing Scale. Statistically significant improvements were achieved by all patients in terms of speech perception and speech reception threshold, and in subjective benefits. The results confirm the literature findings which suggest that patients with asymmetric hearing loss generally gain substantial benefit from cochlear implantation because of the binaural input, with significant improvement in speech perception abilities in noise, speech reception threshold, and squelch abilities.

Investigating Real-World Benefits of High-Frequency Gain in Bone-Anchored Users with Ecological Momentary Assessment and Real-Time Data Logging.

Purpose: To compare listening ability (speech reception thresholds) and real-life listening experience in users with a percutaneous bone conduction device (BCD) with two listening programs differing only in high-frequency gain. In situ real-life experiences were recorded with ecological momentary assessment (EMA) techniques combined with real-time acoustical data logging and standard retrospective questionnaires. Methods: Nineteen experienced BCD users participated in this study. They all used a Ponto 4 BCD from Oticon Medical during a 4-week trial period. Environmental data and device parameters (i.e., device usage and volume control) were logged in real-time on an iPhone via a custom iOS research app. At the end of the trial period, subjects filled in APHAB, SSQ, and preference questionnaires. Listening abilities with the two programs were evaluated with speech reception threshold tests. Results: The APHAB and SSQ questionnaires did not reveal any differences between the two listening programs. The EMAs revealed group-level effects, indicating that in speech and noisy listening environments, subjects preferred the default listening program, and found the program with additional high-frequency gain too loud. This finding was corroborated by the volume log—subjects avoided the higher volume control setting and reacted more to changes in environmental sound pressure levels when using the high-frequency gain program. Finally, day-to-day changes in EMAs revealed acclimatization effects in the listening experience for ratings of “sound quality” and “program suitability” of the BCD, but not for ratings of “loudness perception” and “speech understanding”. The acclimatization effect did not differ among the listening programs. Conclusion: Adding custom high-frequency amplification to the BCD target-gain prescription improves speech reception in laboratory tests under quiet conditions, but results in poorer real-life listening experiences due to loudness.

Test-Retest Differences of the Speech Discrimination Score in Patients with Hearing Loss

Background and Objectives The diagnosis of hearing impairment is based on repeated audiometry, including pure tone audiometry (PTA), speech reception threshold test (SRT), and speech discrimination test (SDT). SDT results particularly show a wide discrepancy upon repeated testing, while malingering is suspected when having more than 12% difference between 3 individual SDT results. Therefore, in this study, we compared the proportion of malingering found in repeated SDT with that found in other audiometric tests and analyzed the characteristics of malingering group in order to reevaluate the current criteria of defining malingering.Subjects and Method We retrospectively assessed the audiometry results of 113 patients (226 ears) with hearing impairment. Each ear was divided into a malingering group and a true hearing loss group. The proportion of ears corresponding to each malingering criterion was compared using a chi-square test. An independent sample t-test was performed to identify the differences between the characteristics between the two groups.Results The number of ears that met the malingering criteria were 19 (8.41%) in PTA, 15 (6.64%) in SRT, and 75 (33.19%) in SDT. There was a significant difference in the proportion of malingering between the 3 hearing test modalities (p&lt;0.001). There was no significant difference in auditory brainstem response, mean age and sex distribution between the malingering group and the true hearing loss group.Conclusion When conducting repeated SDT, there is a risk of misdiagnosing an actual hearing loss patient as a malingering patient under the current malingering criteria. Therefore, the current criteria on SDT requires reevaluation.

Speech Reception Threshold Testing in Iraqi-Speaking Adults

Speech Reception Threshold Testing in Iraqi-Speaking Adults

Investigation on Chinese speech reception threshold of the elderly in noise and reverberation

The elderly is more vulnerable to the detrimental effects of noise and reverberation. In the study, five simulated binaural room impulse responses with different reverberation time (RT) were convolved with test speech signals and background noise. Speech reception threshold (SRT) test was conducted on 22 elderly with different hearing levels (HLs) under different RT and background noise level (BNL) conditions. The results show that the SRT increases with the increase of age and deterioration of HL. The elderly have higher SRT than young adults. There is a high linear correlation between SRT and RT in different age groups and HL groups. Under 40 dBA and 55 dBA BNL conditions, the slope of linear fitting relationship between SRT and RT increases with the increase of age, and increases with the increase of pure tone average auditory. It also shows that the difference between different groups increases with the increase of RT. Under the same RT condition, the SRT in 40 dBA BNL is higher than that in 55 dBA BNL. However, the actual needed speech sound pressure level in 40 dBA BNL to obtain the same speech intelligibility is lower than that in 55 dBA BNL. It is more beneficial to improve the speech intelligibility of the elderly under a lower BNL condition with a sufficient sound pressure level. The architects should take reasonable acoustical measures to reduce the BNL and RT to improve the speech communication of the elderly in rooms.

The effect of monetary reward on listening effort and sentence recognition

Recently we showed that higher reward results in increased pupil dilation during listening (listening effort). Remarkably, this effect was not accompanied with improved speech reception. Still, increased listening effort may reflect more in-depth processing, potentially resulting in a better memory representation of speech. Here, we investigated this hypothesis by also testing the effect of monetary reward on recognition memory performance. Twenty-four young adults performed speech reception threshold (SRT) tests, either hard or easy, in which they repeated sentences uttered by a female talker masked by a male talker. We recorded the pupil dilation response during listening. Participants could earn a high or low reward and the four conditions were presented in a blocked fashion. After each SRT block, participants performed a visual sentence recognition task. In this task, the sentences that were presented in the preceding SRT task were visually presented in random order and intermixed with unfamiliar sentences. Participants had to indicate whether they had previously heard the sentence or not. The SRT and sentence recognition were affected by task difficulty but not by reward. Contrary to our previous results, peak pupil dilation did not reflect effects of reward. However, post-hoc time course analysis (GAMMs) revealed that in the hard SRT task, the pupil response was larger for high than low reward. We did not observe an effect of reward on visual sentence recognition. Hence, the current results provide no conclusive evidence that the effect of monetary reward on the pupil response relates to the memory encoding of speech.

The validity of an isiZulu speech reception threshold test for use with adult isiZulu speakers.

BackgroundThis study continued the development of an isiZulu speech reception threshold (zSRT) test for use with first language, adult speakers of isiZulu.ObjectivesThe objective of this study was to determine the convergent and concurrent validity of the zSRT test.MethodsOne hundred adult isiZulu first-language speakers with normal hearing and 76 first-language, adult isiZulu speakers with conductive or sensorineural hearing losses ranging from mild to severe were assessed on pure tone audiometry and a newly developed isiZulu SRT test. Convergent validity was established through agreement of the zSRT scores with pure tone average (PTA) scores. Concurrent validity was assessed by examining the steepness of the psychometric curve for each word in the zSRT test for each type and degree of hearing loss.ResultsIntraclass correlation coefficient analyses showed zSRT scores were in substantial to very high agreement with PTA scores for the normal hearing and hearing loss groups (NH – right ear ICC consistency = 0.78, left ear ICC = 0.67; HL – right ear ICC consistency = 0.97, left ear ICC consistency = 0.95). The mean psychometric slope (%/dB) at 50% correct perception for all words in the zSRT test was 4.92%/dB for the mild conductive hearing loss group, 5.26%/dB for the moderate conductive hearing loss group, 2.85%/dB for the moderately severe sensorineural hearing loss group and 2.47%/dB for the severe sensorineural hearing loss group. These slopes were appropriate for the degree of hearing loss observed in each group.ConclusionThe zSRT test showed convergent and concurrent validity for assessing SRT in first language, adult speakers of isiZulu.

Testes de fala no ruído na clínica audiológica – Uma Revisão Integrativa

Introdução: A audiometria convencional não é suficientemente confiável para prever a compreensão de uma pessoa num ambiente ruidoso e, desta forma, inserir testes de fala no ruído na rotina clínica audiológica pode ser uma ferramenta útil para detectar possíveis problemas da função auditiva central. Objetivo: Realizar uma revisão integrativa da literatura sobre testes de fala no ruído disponíveis para uso na clínica audiológica. Método: Busca de publicações sem delimitação temporal nos bancos de dados Lilacs, PubMed, Medline, IBCS e SciELO, utilizando-se como descritores: teste de fala no ruído, percepção auditiva, testes de discriminação auditiva, distúrbios auditivos, padronização, desenvolvimento, validação, testes do limiar de recepção da fala, percepção auditiva e perda auditiva. Não houve exclusão por período de publicação. Os artigos foram pesquisados nos meses de junho e julho de 2017. Resultados: Foram localizados um total de 1200 artigos e 39 foram inseridos nesta revisão integrativa por satisfazerem os critérios de inclusão. Nos artigos selecionados, foram localizados 25 materiais diferentes que utilizaram para avaliação de fala no ruído: sílabas, palavras, sentenças, dígitos e associação de palavras e tonalidade e palavras e sentenças. Os tipos de ruídos empregados foram: espectro de fala, ruído tipo babble, ruído branco e ruído estacionário e tais materiais foram desenvolvidos para uso em adultos e/ou crianças e sujeitos com e/ou sem perda auditiva. Conclusão: Todos os autores relataram a importância de inserir testes de fala no ruído na rotina clínica, já que só a audiometria convencional não prevê a compreensão de fala em ambiente ruidoso.

Audiological correlates of cone beam computed tomography (CBCT) in cochlear implant recipients

Objectives: To evaluate the role of Cone beam CT (CBCT) regarding the intracochlear electrode position, the exact localization of the electrode in either the Scala tympani or Scala vestibuli and any accompanying inner ear trauma to the delicate intracochlear structures and furthermore correlate these findings with the hearing thresholds and speech tests in patients with unilateral cochlear implant (CI).Method: A total number of 20 subjects were examined in this study, 6 males and 14 females, their ages ranged from 3 to 10 years who underwent cochlear implantation. CBCT was done to the entire study group 3 months after surgery. After one year, audio logical evaluation was done in the form of aided warble tone response, aided speech reception threshold and early speech perception test (ESP) both in quiet and in noise. The study group was subdivided according to the degree of inner ear trauma into four groups: grade 0 trauma (9 subjects), grade I trauma (3 subjects), grade II trauma (3 subjects), grade III trauma (5 subjects).Results: There was a significant difference among no trauma patients and trauma patients regarding the insertion angle, aided threshold at 250 Hz, percentage of working electrodes and ESP in noise test. Moreover, significant inverse correlation was present between the grade of trauma and both ESP in noise and the percentage of working electrodes.Conclusions: The optimal image quality and the small radiation dose renders CBCT as an optimal and secure imaging tool for the assessment of the CI electrode location and evaluation of inner ear trauma as it affects postoperative programing and hearing perspectives.

Please try harder! The influence of hearing status and evaluative feedback during listening on the pupil dilation response, saliva-cortisol and saliva alpha-amylase levels

The pupil dilation response is sensitive both to listening effort and the emotional significance of a task. We aimed to assess the influence of evaluative feedback on the pupil dilation response using a speech reception threshold (SRT) task. Besides the pupil dilation response, we acquired subjective ratings and two physiological biomarkers sensitive to stress: cortisol and alpha-amylase levels as determined in saliva samples.We included 34 participants with normal hearing (mean age = 52 years, age range 25–67 years) and 29 age-matched participants with mild-to-moderate hearing loss (mean age = 52 years, age range 23–64 years). Half of the participants performed a standard SRT test without feedback, and the other half performed an SRT test in which they did receive feedback and were urged to perform better. The SRT conditions targeted 50% and 71% correct reception of the sentences. Pupil size was recorded and saliva samples were obtained and participants rated their experience of the task.Participants with hearing loss performed more poorly on the SRT test than participants with normal hearing participants receiving feedback had better SRTs in the 71% intelligibility condition and higher peak pupil dilation in both intelligibility conditions than participants who did not receive feedback, irrespective of hearing status. Saliva cortisol level and alpha-amylase activity reflected the usual diurnal patterns but showed no effects of hearing status or feedback. Finally, participants who received feedback experienced more difficulties than those who did not receive feedback, irrespective of hearing status.This study underlines the importance of taking into account the influence of task instructions and feedback in a speech perception task as these factors may influence the experienced difficulties, listening effort, and task performance.

Cochlear implantation for single-sided deafness in children and adolescents

ObjectiveTo evaluate outcomes in pediatric and adolescent patients with single-sided deafness (SSD) undergoing cochlear implantation. MethodsA retrospective cohort design at two tertiary level academic cochlear implant centers. The subjects included nine children ages 1.5 to 15 years-old with single-sided deafness (SSD) who had undergone cochlear implantation in the affected ear. Objective outcome measures included were speech reception testing in quiet and noise, bimodal speech reception threshold testing in noise, tinnitus suppression, and device usage. ResultsNine pediatric and adolescent patients with SSD were implanted between 2011 and 2017. The median age at implantation was 8.9 years (range, 1.5–15.1) and the children had a median duration of deafness 2.9 years (range, 0.8–9.5). There was variability in testing measures due to patient age. Median pre-operative aided word recognition scores on the affected side were <30% regardless of the testing paradigm used. Six patients had pre-operative word testing (4 CNC, median score 25%; 2 MLNT, 8% and 17%). Four patients had pre-operative sentence testing (3 AzBio, median score 44%; 1 HINT-C, 57%). Median post-implantation follow-up interval was 12.3 months (range, 3–27.6 months). Six subjects had post-operative word recognition testing (CNC median, 70%; MLNT 50%, 92%) with a median improvement of 45.5% points. Five subjects had post-operative sentence testing (AzBio, median 82%; HINT, median 76%), with a median improvement of 40.5% points. Eight patients are full time users of their device. Tinnitus and bimodal speech reception thresholds in noise were improved. ConclusionPediatric subjects with SSD benefit substantially from cochlear implantation. Objective speech outcome measures are improved in both quiet and noise, and bimodal speech reception thresholds in noise are greatly improved. There is a low rate of device non-use.

Anatomical and Functional MRI Changes after One Year of Auditory Rehabilitation with Hearing Aids.

Hearing aids (HAs) are an effective strategy for auditory rehabilitation in patients with peripheral hearing deficits. Yet, the neurophysiological mechanisms behind HA use are still unclear. Thus far, most studies have focused on changes in the auditory system, although it is expected that hearing deficits affect a number of cognitive systems, notably speech. In the present study, we used audiometric evaluations in 14 patients with bilateral hearing loss before and after one year of continuous HA use and functional magnetic resonance imaging (fMRI) and cortical thickness analysis in 12 and 10 of them compared with a normal hearing control group. Prior to HA fitting, fMRI activity was found reduced in the auditory and language systems and increased in visual and frontal areas, expanding to multimodal integration cortices, such as the superior temporal gyrus, intraparietal sulcus, and insula. One year after rehabilitation with HA, significant audiometric improvement was observed, especially in free-field Speech Reception Threshold (SRT) test and functional gain, a measure of HA efficiency. HA use increased fMRI activity in the auditory and language cortices and multimodal integration areas. Individual fMRI signal changes from all these areas were positively correlated with individual SRT changes. Before rehabilitation, cortical thickness was increased in parts of the prefrontal cortex, precuneus, fusiform gyrus, and middle temporal gyrus. It was reduced in the insula, supramarginal gyrus, medial temporal gyrus, occipital cortex, posterior cingulate cortex, and claustrum. After HA use, increased cortical thickness was observed in multimodal integration regions, particularly the very caudal end of the superior temporal sulcus, the angular gyrus, and the inferior parietal gyrus/superior temporal gyrus/insula. Our data provide the first evidence that one year of HA use is related to functional and anatomical brain changes, notably in auditory and language systems, extending to multimodal cortices.

The internal and external consistency of a speech reception threshold test for isiZulu speakers with normal hearing sensitivity.

Background and objectivesThis study investigated reliability, particularly the internal and external consistency, of a new isiZulu speech reception threshold (SRT) test.MethodsTo examine internal consistency, 21 adult isiZulu speakers with normal hearing sensitivity completed the SRT test using the first and second halves of the SRT wordlist in the same test session. To examine external consistency, a separate 23 adult isiZulu speakers with normal hearing sensitivity completed the SRT test, using the whole word list on two occasions 4 weeks apart. Consistency of SRT test scores in these test conditions was measured using intraclass correlation coefficient analyses (a measure of the consistency or reproducibility of different observations of the same quantity) and Bland and Altman analyses of agreement (a comparison of measurement error with the expected variation amongst subjects).ResultsIntraclass correlation coefficient values ranged from 0.69 to 0.79, showing the isiZulu test scores were highly consistent between the test and retest conditions used in this study. Bland and Altman analyses showed that isiZulu speakers with normal hearing sensitivity can be expected to return isiZulu SRT test scores that differ by no more than 7.5 dB HL – 8.7 dB HL between original and repeat assessments.ConclusionThe isiZulu SRT test was reliable, showing high internal and external consistency, when used to assess first-language speakers of isiZulu with normal hearing sensitivity. These findings warrant continued development of the isiZulu SRT test for eventual clinical use. This development should include validating this test on first-language speakers of isiZulu with and without hearing loss.