Spatial Release From Masking With Bilateral Bone Conduction Stimulation at Mastoid for Normal Hearing Subjects.

This study investigates the effect of spatial release from masking (SRM) in bilateral bone conduction (BC) stimulation at the mastoid. Nine adults with normal hearing were tested to determine SRM based on speech recognition thresholds (SRTs) in simulated spatial configurations ranging from 0 to 180 degrees. These configurations were based on nonindividualized head-related transfer functions. The participants were subjected to sound stimulation through either air conduction (AC) via headphones or BC. The results indicated that both the angular separation between the target and the masker, and the modality of sound stimulation, significantly influenced speech recognition performance. As the angular separation between the target and the masker increased up to 150°, both BC and AC SRTs decreased, indicating improved performance. However, performance slightly deteriorated when the angular separation exceeded 150°. For spatial separations less than 75°, BC stimulation provided greater spatial benefits than AC, although this difference was not statistically significant. For separations greater than 75°, AC stimulation offered significantly more spatial benefits than BC. When speech and noise originated from the same side of the head, the "better ear effect" did not significantly contribute to SRM. However, when speech and noise were located on opposite sides of the head, this effect became dominant in SRM.

Sensitivity of the antiphasic digits-in-noise test to simulated unilateral and bilateral conductive hearing loss.

OBJECTIVES: The objective of this study is (1) to assess whether the presentation level of the antiphasic digits-in-noise (DIN) test affects the speech recognition threshold (SRT), (2) to evaluate how accurately simulated unilateral and bilateral conductive hearing loss is detected (CHL) and (3) to determine whether increasing the presentation level normalises the antiphasic DIN SRT. DESIGN: Participants performed antiphasic and diotic DINs at different presentation levels with unilateral, bilateral or no earplugs. STUDY SAMPLE: Twenty-four and twelve normal hearing adults. RESULTS: Without earplugs, antiphasic DIN SRTs did not differ between 60 and 80 dB SPL. At 60 dB SPL, the antiphasic DIN correctly classified 92% of the unilateral earplug cases; the diotic DIN 25%. The binaural intelligibility level difference did not differ between the no-earplug condition and the condition with bilateral earplugs when the presentation was increased with the attenuation level. CONCLUSIONS: In normal hearing participants, diotic and antiphasic DIN SRTs are independent of presentation level above a minimum level of 60 dB SPL. The antiphasic DIN is more sensitive than the diotic DIN for detecting unilateral CHL; not for bilateral CHL. The effect of CHL on DIN SRTs can be largely compensated by increasing the presentation level. Audibility plays an important role in the antiphasic and diotic DIN.

Effect of face masks on speech understanding: A clinical perspective during speech audiometry.

The objective was to measure the effect of various face masks on speech recognition threshold and the word recognition score in the presence of varying background noise levels. 20 normal-hearing adult subjects (a total of 40 ears) participated. Pure tone audiometry followed by speech recognition threshold and word recognition score at the most comfortable level in varying signal-to-noise ratios (SNR0, SNR10, and SNR15) using surgical, pleated cloth, and N95 masks. Using surgical, cloth, and N95 masks, speech recognition thresholds increased by 1.8 dB, 4.4 dB, and 5.05 dB, respectively. Word recognition scores decreased by 32% without a mask, 43.7% in a surgical mask, 46.3% in a cloth mask, and 46.7% in N95 mask conditions, between SNR15 and SNR0. The speech recognition threshold was negatively affected with cloth and N95 masks. Surgical masks do not affect the word recognition scores at lower background noise levels. However, as the signal-to-noise ratio decreased, even the surgical, cloth, and N95 masks significantly impacted the word recognition score even in normal-hearing individuals.

Pure-tone audiometry without bone-conduction thresholds: using the digits-in-noise test to detect conductive hearing loss.

Objective: COVID-19 has been prohibitive to traditional audiological services. No- or low-touch audiological assessment outside a sound-booth precludes test batteries including bone conduction audiometry. This study investigated whether conductive hearing loss (CHL) can be differentiated from sensorineural hearing loss (SNHL) using pure-tone air conduction audiometry and a digits-in-noise (DIN) test.Design: A retrospective sample was analysed using binomial logistic regressions, which determined the effects of pure tone thresholds or averages, speech recognition threshold (SRT), and age on the likelihood that participants had CHL or bilateral SNHL.Study sample: Data of 158 adults with bilateral SNHL (n = 122; PTA0.5-4 kHz > 25 dB HL bilaterally) or CHL (n = 36; air conduction PTA0.5-4 kHz > 25 dB HL and ≥20 dB air bone gap in the affected ears) were included.Results: The model which best discriminated between CHL and bilateral SNHL used low-frequency pure-tone average (PTA), diotic DIN SRT, and age with an area under the ROC curve of 0.98 and sensitivity and specificity of 97.2 and 93.4%, respectively.Conclusion: CHL can be accurately distinguished from SNHL using pure-tone air conduction audiometry and a diotic DIN. Restrictions on traditional audiological assessment due to COVID-19 require lower touch audiological care which reduces infection risk.

The effect of an active transcutaneous bone conduction device on spatial release from masking.

Objective: The aim was to quantify the effect of the experimental active transcutaneous Bone Conduction Implant (BCI) on spatial release from masking (SRM) in subjects with bilateral or unilateral conductive and mixed hearing loss.Design: Measurements were performed in a sound booth with five loudspeakers at 0°, +/-30° and +/-150° azimuth. Target speech was presented frontally, and interfering speech from either the front (co-located) or surrounding (separated) loudspeakers. SRM was calculated as the difference between the separated and the co-located speech recognition threshold (SRT).Study Sample: Twelve patients (aged 22-76 years) unilaterally implanted with the BCI were included.Results: A positive SRM, reflecting a benefit of spatially separating interferers from target speech, existed for all subjects in unaided condition, and for nine subjects (75%) in aided condition. Aided SRM was lower compared to unaided in nine of the subjects. There was no difference in SRM between patients with bilateral and unilateral hearing loss. In aided situation, SRT improved only for patients with bilateral hearing loss.Conclusions: The BCI fitted unilaterally in patients with bilateral or unilateral conductive/mixed hearing loss seems to reduce SRM. However, data indicates that SRT is improved or maintained for patients with bilateral and unilateral hearing loss, respectively.

A Comparison of Surgical Auditory Nerve Response and Speech Outcomes in Patients with Post-meningitic Deafness and Without Cochlear Osteogenesis Who Underwent Cochlear Implantation.

Objective Patients with post-meningitis deafness remain challenging candidates for cochlear implantation (CI) which can be difficult due to fibrosis or ossification of the inner ear, and their outcomes remain doubtful. We assessed the surgical and audiological outcomes of CI in patients with profound sensorineural hearing loss caused by meningitis and compared those outcomes to patients without cochlear ossification. Methods This retrospective cross-sectional study was carried out at King Fahad General Hospital, Jeddah, Saudi Arabia. Among 246 patients who underwent cochlear implantation, 13 patients with post-meningitic deafness were identified (Group 1). A matched control group, including patients with deafness due to other causes who did not have cochlea osteogenesis, was selected (Group 2). For all patients, data were collected from medical records, including surgical and audiological outcomes. Results Sclerosis of the cochlea was high in Group 1 (46.2%). There were no postoperative surgical complications in either group. Responses of the auditory nerve action potential obtained through auditory response telemetry (ART) or the neural response telemetry (NRT) were recorded. There was no significant difference between the two groups regarding the intraoperative and the postoperative ART or NRT at selected electrodes representing the entire cochlea. Likewise, no significant difference regarding the speech recognition test (SRT) was detected. Conclusions Cochlear implantation is a safe procedure without surgical complications in post-meningitis patients. Furthermore, early CI in children was associated with favorable outcomes in terms of preservation of the auditory nerve response, restoration of speech discrimination, and recognition to levels comparable to patients with deafness due to other causes. Early audiological assessment in meningitis patients is recommended to identify hearing loss and eventually to offer CI.

Psychometrically equivalent bisyllabic words for speech recognition threshold testing in Vietnamese.

OBJECTIVE: This study identified, digitally recorded, edited and evaluated 89 bisyllabic Vietnamese words with the goal of identifying homogeneous words that could be used to measure the speech recognition threshold (SRT) in native talkers of Vietnamese. DESIGN: Native male and female talker productions of 89 Vietnamese bisyllabic words were recorded, edited and then presented at intensities ranging from -10 to 20 dBHL. Logistic regression was used to identify the best words for measuring the SRT. Forty-eight words were selected and digitally edited to have 50% intelligibility at a level equal to the mean pure-tone average (PTA) for normally hearing participants (5.2 dBHL). STUDY SAMPLE: Twenty normally hearing native Vietnamese participants listened to and repeated bisyllabic Vietnamese words at intensities ranging from -10 to 20 dBHL. RESULTS: A total of 48 male and female talker recordings of bisyllabic words with steep psychometric functions (>9.0%/dB) were chosen for the final bisyllabic SRT list. Only words homogeneous with respect to threshold audibility with steep psychometric function slopes were chosen for the final list. CONCLUSIONS: Digital recordings of bisyllabic Vietnamese words are now available for use in measuring the SRT for patients whose native language is Vietnamese.

Cochlear function tests in estimation of speech dynamic range.

OBJECTIVES: The loss of active cochlear mechanics causes elevated thresholds, loudness recruitment, and reduced frequency selectivity. The problems faced by hearing-impaired listeners are largely related with reduced dynamic range (DR). The aim of this study was to determine which index of the cochlear function tests correlates best with the DR to speech stimuli. METHODS: Audiological data on 516 ears with pure tone average (PTA) of ≤55 dB and word recognition score of ≥70% were analyzed. PTA, speech recognition threshold (SRT), uncomfortable loudness (UCL), and distortion product otoacoustic emission (DPOAE) were explored as the indices of cochlear function. Audiometric configurations were classified. Correlation between each index and the DR was assessed and multiple regression analysis was done. RESULTS: PTA and SRT demonstrated strong negative correlations with the DR (r = -0.788 and -0.860, respectively), while DPOAE sum was moderately correlated (r = 0.587). UCLs remained quite constant for the total range of the DR. The regression equation was Y (DR) = 75.238 - 0.719 × SRT (R(2 )=( )0.721, p < 0.001). The other variables such as audiometric configurations and DPOAE sum were excluded from the final model. CONCLUSION: SRT was the most predictive of the DR among the indices of the cochlear function tests. A reduced DR in cochlear hearing loss was the product of an elevated audiometric threshold and a relatively constant UCL level. The results enable prediction of the DR from SRT and possibly PTA using the suggested regression equation.

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 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.

Comparison of Manual and Automatic Evaluation of Speech Recognition Threshold Using Mandarin Disyllabic Test / 听力学及言语疾病杂志

Objective To compare the results of manually -tested speech recognition threshold (SRT ) with automatically software -recorded SRT in the trial of Mandarin disyllabic test ,exploring the significance to the clini-cal applying .Methods 128 normal people of different ages without hearing loss and 57 workers exposed to noise in an automobile manufacturing was selected .These two group of volunteers speak mainly Mandarin in their daily life . MADSEN Conera (Danmark) clinical audiometr was applied .A group of double syllable word list with the same dif-ficulty of equivalence was used as test material .The initial presentation level was 20 dB HL higher than PTA .Then compared the results of manually -tested SRT with automatically software -recorded SRT .Results In the normal group ,the automatic value SRT was 7 .84 ± 3 .98 dB HL ,the manual value was 9 .19 ± 4 .47 dB HL ,and the average value of speech frequency threshold was 7 .63 ± 5 .78 dB HL .In the noise group ,the automatic value SRT was 6 .10 ± 8 .40 dB HL ,the manual value was 18 .81 ± 9 .52 dB HL ,and the average value of language frequency threshold was 27 .18 ± 19 .13 dB HL .There was significant difference between the values of SRT tested manually and recorded automatically (P<0 .01) .Conclusion There are differences between SRT valued manually and automatically .The SRT in people with normal hearing can be tested using automatic -recorded method .This method is convenient for screening in people without hearing loss .To exam in people with hearing loss ,the manual test is more appropriate .

Reliability of Speech Recognition Threshold Test Using the Korean Standard Bisyllabic Word List for Adults in Comparison with Conventional Hahm's List / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The purpose of this study was to compare a newly developed Korean standard bisyllabic word list for adults (KS-BWL-A) against the conventional Hahm's List based on the reliability in speech recognition threshold (SRT) test. SUBJECTS AND METHOD: Twelve adults with normal hearing and 11 hearing-impaired patients participated in this study. After excluding 10 words that are common in both lists, 26 bisyllabic words from each list were used for comparison in this study. SRTs were obtained using the modified ascending method. RESULTS: The mean SRTs measured by KS-BWL-A were 1.9 dB lower for the normal hearing group and 2.7 dB lower for the hearing-impaired group than those measured by the conventional Hahm's list with statistical significance (p=0.025 and p=0.045). In both groups, the pure tone averages (PTAs) were highly correlated (correlation coefficient >0.7, p<0.001) with SRTs measured using old and new lists, and the differences between PTA and SRT were within 3 dB for both lists. CONCLUSION: These results suggest that both KS-BWL-A and the conventional list are reliable methods as adult SRT tests and that two lists are not considerably different. However, speech recognition was slightly easier by the new list than it was by the conventional list. Authors propose the KS-BWL-A as a standard word list for SRT measurement in Korea.