Mean Speech Recognition Threshold Research Articles

Infliximab for the Treatment of Inflammatory Labyrinthitis: A Retrospective Cohort Study.

Inflammatory labyrinthitis is defined as a fluctuant vestibulo-cochlear syndrome associated with an impairment of the blood-labyrinthine barrier (BLB) on delayed FLAIR MRI sequences. Systemic and intratympanic corticosteroids are the gold standard treatment but their effect is frequently insufficient. The objective is here to determine whether infliximab could be of value in the treatment of bilateral inflammatory labyrinthitis. A retrospective monocentric study was conducted between January 2013 and December 2021. All patients included in the study were affected with a bilateral vestibulo-cochlear syndrome associated with bilateral blood-labyrinthine barrier impairment. Patients were administered infliximab at the dose of 5 mg/kg every 6 weeks for 6 months. Audiometry, MRI with delayed FLAIR sequences on the labyrinth, and corticosteroid doses still required were assessed both before and after treatment with infliximab was completed. Pure-tone average (PTA) was the primary outcome. The secondary outcomes were the speech recognition threshold (SRT), the Dizziness Handicap Inventory (DHI) score, and the corticosteroid (CS) dose. A total of nine patients including five men and four women were enrolled in the study. Thirteen ears were analyzed. After a 6-month period of treatment, the mean PTA (54 ± 24 db versus 66 ± 22 db; p = 0.027), SRT (54 ± 37 db versus 66 ± 32 db; p = 0.041) and DHI score (27 ± 15 versus 9 ± 2; p = 0.032) significantly improved. After the 6-month treatment period, the mean CS dose decreased from 38 ± 33 to 6 ± 5 mg/day (p = 0.003). We conclude that infliximab substantially improves the vestibulo-cochlear function in patients with bilateral inflammatory labyrinthitis and could be of value in corticosteroid-dependent cases.

Functional consequences of extended high frequency hearing impairment: Evidence from the speech, spatial, and qualities of hearing scale.

Hearing loss in the extended high frequencies, despite a normal audiogram, could affect speech-in-noise recognition. However, it is not known if extended high frequency (EHF) hearing loss is associated with everyday listening and communication deficits. The present study aimed to determine the functional effects of impaired EHF hearing among adults using the Speech, Spatial, and Qualities of Hearing Scale (SSQ). A secondary objective was to evaluate the relationship between objective (speech-in-noise recognition) and subjective (SSQ) measures of hearing function. Listeners with EHF hearing loss provided lower SSQ ratings compared with their EHF-normal counterparts. The lower ratings could not be attributed to the age or standard audiogram of the listeners. Ratings from more than 50% of EHF-impaired listeners were below the 2 SD cutoff point obtained from EHF-normal listeners. The mean speech recognition threshold was poorer for EHF-impaired listeners, and a poorer speech recognition threshold was associated with lower SSQ ratings, i.e., poorer self-reported hearing ability. For some listeners, EHF hearing loss could be the missing link between self-reported hearing difficulty in the presence of a normal audiogram. These findings provide evidence for the functional deficits associated with EHF hearing loss and invoke the need for future investigations into the management of EHF loss.

Hearing Impairment in the Extended High Frequencies in Children Despite Clinically Normal Hearing.

Pediatric hearing impairment, regardless of degree and type, has a detrimental effect on speech perception, cognition, oral language development, academic outcomes, and literacy. Hearing assessment in the clinic is limited to 8 kHz although humans can hear up to 20 kHz. Hearing impairment in the extended high frequencies (EHFs > 8 kHz) can occur despite clinically normal hearing. However, to date, the nature and effects of EHF hearing impairment in children remain unknown. The goals of the present study were to determine the effects of EHF hearing impairment on speech-in-noise recognition in children and to examine whether hearing impairment in the EHFs is associated with altered cochlear functioning in the standard frequencies. A volunteer sample of 542 participants (4 to 19 years) with clinically normal audiograms were tested. Participants identified with EHF impairment were assigned as cases in a subsequent case-control study. EHF loss was defined as hearing thresholds greater than 20 dB in at least one EHFs (10, 12.5, or 16 kHz). Speech recognition thresholds in multi-talker babble were measured using the digit triplet test. Distortion product otoacoustic emissions ( f2 = 2, 3, 4, and 5 kHz) were measured to assess cochlear functioning. Thresholds in the EHFs were as reliable as those in the standard frequency range. Thirty-eight children had EHF hearing impairment regardless of a clinically normal audiogram. A linear mixed-effects model revealed that children with EHF hearing impairment had higher (poorer) mean speech recognition threshold than children with normal EHF sensitivity ( estimate = 2.14 dB, 95% CI: 1.36 to 3.92; effect size = small). The overall magnitude of distortion product otoacoustic emissions was lower for children with EHF impairment ( estimate = -2.47 dB, 95% CI: -4.60 to -0.73; effect size = medium). In addition, the pure-tone average for standard audiometric frequencies was relatively higher for EHF-impaired children ( estimate = 3.68 dB, 95% CI: 2.56 to 4.80; effect size = small). Hearing impairment in the EHFs is common in children despite clinically normal hearing and can occur without a history of otitis media. EHF impairment is associated with poorer speech-in-noise recognition and preclinical cochlear deficits in the lower frequencies where hearing thresholds are normal. This study highlights the clinical need to identify EHF impairments in children.

Digits-in-noise test in Brazilian Portuguese: how demographic and socioeconomic variables influence normal-hearing subjects.

Verify how demographic and socioeconomic variables on the in-noise speech recognition threshold (SRT) from the digits-in-noise test (DIN) in Brazilian Portuguese influence normal-hearing subjects. Cross-sectional, prospective study. The convenience sample had 151 normal-hearing subjects between 12 and 79 years (mean=34.66) who underwent pure tone audiometry and digits-in-noise test with white noise using a sequence of three numbers in diotic stimulus (in-phase) on the same day. The DIN was performed using a Motorola Z3 Play smartphone with internet access and in-ear headphones. In-noise digit speech recognition threshold (SRT) was analyzed for gender, age, educational levels, and socioeconomic status. We used the non-parametric version of the Kruskal-Wallis and Mann-Whitney U tests to compare independent samples adopting a significance level of 5%. The mean SRT was -8.47 dBNA (SD -3.89) with a median of -9.6 dBNA. The SRT was proportionally inverse to educational levels and socioeconomic status and more negative (better) with lower age groups. Gender did not influence the DIN SRT. Age, educational levels, and socioeconomic status influenced the DIN threshold. These variables must be considered when analyzing DIN performance in Brazilian Portuguese in normal-hearing subjects.

Multicentre cohort study of cochlear implantation outcomes in Thailand

ObjectivesTo report the status and outcomes of cochlear implantation in Thailand.DesignCohort study.SettingTertiary care and university hospitals.ParticipantsPatients who underwent cochlear implant surgery in Thailand.InterventionsThis project collected data from all government and...

Hearing rehabilitation with osseointegrated hearing implant in bilateral congenital external auditory canal atresia

Introduction and objectivesCongenital atresia of the external auditory canal (EAC) is a congenital defect present in one in every 10,000–20,000 births. It causes conductive hearing loss, with an air-bone gap of 50–60dB. Early amplification is essential in bilateral cases to ensure normal language development. The aim of this study is to present the osseointegrated hearing implant as a treatment for bilateral EAC atresia, reviewing the audiometric results and the rate of complications. Material and methodsRetrospective analysis of patients diagnosed with bilateral congenital EAC atresia under follow-up in the pediatric ENT clinic of the ENT and Head and Neck Surgery department of a Portuguese Tertiary Hospital, between 2003 and 2019. We reviewed the medical records and collected information on the assessment of the initial audiometric status. In the cases submitted for implantation with an osseointegrated hearing implant, we analyzed the details of follow-up, including immediate and long-term post-operative complications, as well as the audiometric results. ResultsWe present 8 pediatric patients, 6 girls and 2 boys, with a diagnosis of bilateral congenital EAC atresia. The audiometric assessment revealed moderate to severe bilateral conductive hearing loss with a mean speech recognition threshold (SRT) of 51dB. Six patients underwent osseointegrated hearing implantation. All 6 patients showed good audiometric results, with an average SRT of 20dB and closure of the air-bone gap. ConclusionsThe osseointegrated hearing implant was an effective treatment option in these patients, without significant morbidity or complications. Osseointegrated hearing implantation should be considered first line treatment for children with bilateral congenital EAC atresia, as it presents good functional results and a high level of patient satisfaction.

Subtotal Petrosectomy with Cochlear Implantation or Osseointegrated Hearing Rehabilitation: A Single Institutional Study.

To examine audiologic outcomes and operative considerations for patients undergoing subtotal petrosectomy (STP) followed by implantable hearing restoration. Retrospective review. Tertiary academic referral hospital. All patients who underwent STP and implantable hearing restoration from 2014 to 2020. Single or staged STP with cochlear implantation (CI) or placement of an osseointegrated hearing implant (OHI). Indications for STP and CI or OHI; postoperative complication and reoperation rates; audiologic outcomes through speech recognition thresholds, AzBio sentence scores, and consonant-nucleus-consonant scores. Twenty-six adults (age 33-85) and six children (age 1-17) underwent 37 STP procedures with 33 CIs and four OHI. Thirty-one cases were planned single-stage, but six (16%) cases required revision surgery postoperatively due to refractory postauricular infection and breakdown of wound closure. Therefore, 25 cases were single procedures and 12 were staged. Indications for staged procedures included extensive cholesteatoma (n = 5, 42%), chronic middle ear inflammation (n = 5, 42%), and osteoradionecrosis (n = 2, 17%). No patients with OHI required revision surgery. For patients undergoing CI, the mean speech recognition thresholds improved from 80 ± 21 dB to 31 ± 9 dB (p < 0.001), mean aided AzBio scores improved from 11% to 43% (p = 0.002) and aided consonant-nucleus-consonant word scores improved from 6% to 47% (p < 0.001) in quiet. Subtotal petrosectomy is effective for creating a safe, dry ear in patients with chronic inflammation or anatomically challenging ears. Rehabilitative hearing options following STP can be achieved safely, restoring hearing to an acceptable level with CI. Careful consideration should be undertaken to approach as a single or staged procedure.

Development of SC-10: A psychometrically equivalent Singapore Mandarin disyllabic word list for clinical speech audiometry use.

ObjectiveThe aim of this study is to develop and evaluate a set of psychometrically equivalent disyllabic wordlist (SC-10) in Singapore Mandarin for clinical use.Study designA preliminary set of 1000 words were obtained from a dictionary of frequently used words by Singapore students. Ten native judges rate the familiarity level of each word. This is followed by a face-to-face public survey to rank the shortlisted word set from most to least familiar. The final 108 disyllabic words were recorded by a native female talker. 20 normal hearing subjects were used to obtain the percentage of correct word recognition at 24 intensity levels (−10 dB HL to 26 dB HL in 2 dB increment). Psychometric function slopes were calculated for each word. 100 words were eventually chosen and assigned into ten 10-word lists based on a psychometric balancing protocol. Minor digital adjustments were made to the intensity of each wordlist to improve their auditory homogeneity.The developed SC-10 wordlists were validated by a separate group of 25 normal hearing subjects. Test-retest reliability was carried out on 20 out of 25 participants at the selected intensity levels (SRT-5, SRT, SRT+5).ResultsThe calculated regression slopes in the psychometric functions for the ten lists are between 8.0 and 9.8%/dB. Single factor ANOVA analysis showed no significant difference in both the mean intensity required to obtain 50% recognition score (f = 0.109, df = 9, p = 0.999) and the slopes of the psychometric functions (f = 0.078, df = 9, p = 0.999) between the ten word lists. List validation on 25 normal hearing participants (PTA = 11.0 dB HL, SD = 4.3) showed a mean speech recognition threshold (SRT) of 9.3 dB HL (SD = 3.5)and regression slope of 8.395%/dB. Quadratic regression analysis showed a positive correlation (r2 = 0.923) between presentation level and word recognition score (WRS). The difference between PTA and SRT of each subject all fall within the clinically acceptable difference of 10 dB HL. Test-retest reliability, carried out on 20 subjects at three levels (SRT-5, SRT, and SRT+5 dB), showed no significance difference between word recognition score when the same participant is tested again at the same intensity level using a different wordlist.ConclusionAll in all, it shows that the SC-10 speech materials are valid for clinical use for Mandarin speech audiometry in Singapore.

Hearing rehabilitation with osseointegrated hearing implant in bilateral congenital external auditory canal atresia

Introduction and objectivesCongenital atresia of the external auditory canal (EAC) is a congenital defect present in one in every 10,000–20,000 births. It causes conductive hearing loss, with an air-bone gap of 50–60dB. Early amplification is essential in bilateral cases to ensure normal language development. The aim of this study is to present the osseointegrated hearing implant as a treatment for bilateral EAC atresia, reviewing the audiometric results and the rate of complications. Material and methodsRetrospective analysis of patients diagnosed with bilateral congenital EAC atresia under follow-up in the pediatric ENT clinic of the ENT and Head and Neck Surgery department of a Portuguese Tertiary Hospital, between 2003 and 2019. We reviewed the medical records and collected information on the assessment of the initial audiometric status. In the cases submitted for implantation with an osseointegrated hearing implant, we analyzed the details of follow-up, including immediate and long-term post-operative complications, as well as the audiometric results. ResultsWe present 8 pediatric patients, 6 girls and 2 boys, with a diagnosis of bilateral congenital EAC atresia. The audiometric assessment revealed moderate to severe bilateral conductive hearing loss with a mean speech recognition threshold (SRT) of 51dB. Six patients underwent osseointegrated hearing implantation. All 6 patients showed good audiometric results, with an average SRT of 20dB and closure of the air-bone gap. ConclusionsThe osseointegrated hearing implant was an effective treatment option in these patients, without significant morbidity or complications. Osseointegrated hearing implantation should be considered first line treatment for children with bilateral congenital EAC atresia, as it presents good functional results and a high level of patient satisfaction.

Effects of Monaural Asymmetry and Target-Masker Similarity on Binaural Advantage in Children and Adults With Normal Hearing.

Purpose For colocated targets and maskers, binaural listening typically offers a small but significant advantage over monaural listening. This study investigated how monaural asymmetry and target-masker similarity may limit binaural advantage in adults and children. Method Ten Mandarin-speaking Chinese adults (aged 22-27 years) and 12 children (aged 7-14 years) with normal hearing participated in the study. Monaural and binaural speech recognition thresholds (SRTs) were adaptively measured for colocated competing speech. The target-masker sex was the same or different. Performance was measured using headphones for three listening conditions: left ear, right ear, and both ears. Binaural advantage was calculated relative to the poorer or better ear. Results Mean SRTs were significantly lower for adults than children. When the target-masker sex was the same, SRTs were significantly lower with the better ear than with the poorer ear or both ears (p < .05). When the target-masker sex was different, SRTs were significantly lower with the better ear or both ears than with the poorer ear (p < .05). Children and adults similarly benefitted from target-masker sex differences. Substantial monaural asymmetry was observed, but the effects of asymmetry on binaural advantage were similar between adults and children. Monaural asymmetry was significantly correlated with binaural advantage relative to the poorer ear (p = .004), but not to the better ear (p = .056). Conclusions Binaural listening may offer little advantage (or even a disadvantage) over monaural listening with the better ear, especially when competing talkers have similar vocal characteristics. Monaural asymmetry appears to limit binaural advantage in listeners with normal hearing, similar to observations in listeners with hearing impairment. While language development may limit perception of competing speech, it does not appear to limit the effects of monaural asymmetry or target-masker sex on binaural advantage.

Development of a Smartphone-Based Digits-in-Noise Test in Korean: a Hearing Screening Tool for Speech Perception in Noise.

BackgroundThe digits-in-noise (DiN) test is a speech-in-noise test to measure speech recognition threshold in noise adaptively. Herein, we aimed to develop the Korean version of the DiN test to provide a useful hearing screening tool for clinical as well as research purposes.MethodSpoken monosyllabic digits from 0 to 9 were recorded by a female speaker. The test list was constructed such that each digit was placed in three different positions. An optimization procedure was conducted to equate the audibility of each digit. After the optimization, the smartphone application for the Korean DiN (K-DiN) test was developed. For the adaptive measurement procedure, 180 new DiN triplets separated into six lists of 30 were created. Mean speech recognition threshold values for each list and session were measured to examine the test-retest and training effects of the test materials. In addition, speech recognition threshold values measured by different devices were compared to determine whether the speech recognition threshold levels differed.ResultsOptimization results showed that the mean speech recognition threshold and slope were −11.55 dB signal-to-noise ratio and 10.21%/dB, respectively, which are comparable to levels shown in different-language versions of the DiN test. The results of the test-retest and training effects revealed no significant differences among the test sessions and lists. Additionally, the mean speech recognition threshold values measured by four different devices were not different, indicating the reliability of the test materials.ConclusionWe believe this study is the first to attempt to develop a K-DiN test. Our results indicate that this test can be used as a potentially reliable hearing screening tool.

Masking Effects in the Perception of Multiple Simultaneous Talkers in Normal-Hearing and Cochlear Implant Listeners.

For normal-hearing (NH) listeners, monaural factors, such as voice pitch cues, may play an important role in the segregation of speech signals in multitalker environments. However, cochlear implant (CI) users experience difficulties in segregating speech signals in multitalker environments in part due to the coarse spectral resolution. The present study examined how the vocal characteristics of the target and masking talkers influence listeners’ ability to extract information from a target phrase in a multitalker environment. Speech recognition thresholds (SRTs) were measured with one, two, or four masker talkers for different combinations of target-masker vocal characteristics in 10 adult Mandarin-speaking NH listeners and 12 adult Mandarin-speaking CI users. The results showed that CI users performed significantly poorer than NH listeners in the presence of competing talkers. As the number of masker talkers increased, the mean SRTs significantly worsened from –22.0 dB to –5.2 dB for NH listeners but significantly improved from 5.9 dB to 2.8 dB for CI users. The results suggest that the flattened peaks and valleys with increased numbers of competing talkers may reduce NH listeners’ ability to use dips in the spectral and temporal envelopes that allow for “glimpses” of the target speech. However, the flattened temporal envelope of the resultant masker signals may be less disruptive to the amplitude contour of the target speech, which is important for Mandarin-speaking CI users’ lexical tone recognition. The amount of masking release was further estimated by comparing SRTs between the same-sex maskers and the different-sex maskers. There was a large amount of masking release in NH adults (12 dB) and a small but significant amount of masking release in CI adults (2 dB). These results suggest that adult CI users may significantly benefit from voice pitch differences between target and masker speech.

Audiological benefit and subjective satisfaction of children with the ADHEAR audio processor and adhesive adapter

ObjectivesThe main objective of this study was to evaluate the audiological benefit of the ADHEAR system in a group of children with a uni- or bilateral conductive hearing loss (CHL) during a short-term exposure of three weeks, and to compare it to a conventional bone conduction hearing aid (BCHA) on a softband. The secondary aim was to assess the quality of life improvement and patient satisfaction with the ADHEAR system. Methods and materialsThe study was designed as a prospective study with repeated measures, where each subject served as his/her own control. Ten children (4–17 y/o) with a uni- or bilateral congenital or acquired CHL were included in this study. Pure tone audiometry and speech audiometry in quiet, both unaided and aided, were performed initially with the ADHEAR system and a BCHA on a softband, and after three weeks with the ADHEAR alone. Furthermore, patient satisfaction and quality of life were assessed using the SSQ12 and the ADHEAR questionnaire. ResultsThe mean unaided free field hearing threshold of 50 dB HL (with 95%CI between 41.7 and 57.5 dB HL) expressed in ‘Bureau International d’Audiophonologie’ (BIAP), improved significantly by 22 dB (13.0–29.9) with the ADHEAR and by 23 dB (13.6–32.9) with the BCHA (p < 0.001). Furthermore, the mean unaided speech recognition threshold (SRT) in quiet improved significantly by 19 dB (10.3–28.1) with the ADHEAR and by 21 dB (12.6–29.4) with the BCHA (p < 0.001). For both audiological tests, there were no significant differences between the ADHEAR and the BCHA.After three weeks of use, the mean pure tone threshold of 28 dB HL (20.0–36.5) and the mean SRT of 47 dB SPL (41.9–51.5) with the ADHEAR system were comparable and not significantly different than the outcomes during the first visit.Speech understanding in noise and in multiple streams, sound localization and sound quality were rated significantly better with the ADHEAR, compared to the ratings without the ADHEAR system (p < 0.001). None of the children reported skin irritations or pain. ConclusionsThe children included in our study had significantly improved hearing thresholds, speech perception in quiet and quality of life with the ADHEAR. The device can be an effective treatment method and a valuable alternative to other BCHA for children with a CHL, although the subjective experience of each child has to be taken into account. Clinical trial registration numberNCT03327194.

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 influence of female versus male speakers' voice on speech recognition thresholds in noise: Effects of low- and high-frequency hearing impairment

PurposeTo investigate the effect of female versus male speakers' voice on the ability to recognize speech in noise in two groups of sensorineural hearing-impaired listeners, one group with impairment at low frequencies and the other at high frequencies.MethodEight participants with high-frequency hearing impairments (Hf-HI) and seven with low-frequency hearing impairments (Lf-HI) participated. Sixteen normal hearing (NH) participants served as reference. The sentences from the hearing in noise test, read by a female or a male speaker, were presented monaurally with a background noise. In an adaptive procedure, the mean speech recognition threshold, for 50% correctly recognized sentences, was calculated for the female and male voice and each test subject.ResultsThe Hf-HI group had significantly greater difference in signal-to-noise ratio (SNR) results between female and male voices. Irrespective of hearing impairment, the female voice required 2.1 dB better SNR. In addition, the NH group showed a small but significant difference in favor of the male voice.ConclusionsResults indicate that speaker gender matters for hearing impaired and NH individuals' ability to recognize speech in noise.

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.

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

Received March 6, 2012 Revised May 2, 2012 Accepted May 10, 2012 Address for correspondence Jung-Hak Lee, AuD, PhD Department of Audiology, Hallym University of Graduate Studies, 405 Yeoksam-ro, Gangnam-gu, Seoul 135-841, Korea Tel +82-2-2051-4950 Fax +82-2-3453-6618 E-mail leejh@hallym.ac.kr Background and ObjectivesZZThe 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 MethodZZTwelve 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. ResultsZZThe 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. ConclusionZZThese 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. Korean J Otorhinolaryngol-Head Neck Surg 2012;55:350-4

Reference sound pressure level for Korean speech audiometry

Objective: The purpose of this study was to examine the reference sound pressure level (RSPL) for Korean speech audiometry which was defined as the reference speech recognition threshold level (RSRTL) equivalent to 0 dB HL at the audiometer. Study sample: Subjects consisted of 20 adults (40 ears) with normal hearing sensitivity. Design: Puretone thresholds (PTs) were obtained in 2 dB steps at each octave band. The newly developed Korean bisyllabic words were used to establish the speech recognition thresholds (SRTs). The SRT was the level at 50% correct responses based on the psychometric function performed from -8 dB HL (12 dB SPL) up to the level at or above 90% correct responses in 2 dB steps. Results Conclusions: The mean SRT was 23.44 dB SPL for sets comprised of 36 Korean bisyllabic words. Thus, the difference between English and Korean RSRTLs was about 3.44 dB. We recommend further study to recalculate the RSRTL for Korean speech audiometry with more subjects.SumarioObjetivo: El propósito de este estudio fue examinar el nivel de presión sonora de referencia (RSPL) para la logoaudiometría en coreano, que fue definido como el nivel umbral de referencia para el reconocimiento del lenguaje (RSRTL), equivalente a 0 dB HL en el audiómetro. Muestra Del Estudio: Los sujetos de estudio fueron 20 adultos (40 oídos) con sensibilidad auditiva normal. Diseño: Se obtuvieron umbrales tonales puros (PT) en pasos de 2 dB para cada banda de octava. Se usaron las recientemente desarrolladas palabras bisilábicas coreanas para establecer los umbrales de reconocimiento del lenguaje (SRT). El SRT fue el nivel donde se obtuvo un 50% de respuestas correctas, con base en la función psicométrica realizada desde −8 dB HL (12 dB SPL) hasta un nivel ubicado donde se logra un 90% o mayor de respuestas correctas, en pasos de 2 dB. Resultados Y Conclusiones: La mediana del SRT fue de 23.44 dB SPL para listas de 36 palabras bisilábicas coreanas. Por tanto, la diferencia entre el SRT en coreano y en inglés fue de 3.44 dB. Recomendamos estudios adicionales para recalcular el RSRTL para la logoaudiometría en coreano con más sujetos.

Automatic scoring of responses to the hearing in noise test using utterance verification based on hidden Markov models.

The hearing in noise test (HINT) is widely used in clinical settings to measure patients’ speech recognition thresholds (SRTs). The patient must repeat 20 sentences presented at signal-to-noise ratios (SNRs) that change adaptively throughout the test. HINT varies the SNR of the sentences according to the patient’s responses, so each response must be scored by a human judge before the next sentence is presented. An utterance verification engine (UVE) would remove both the need for a human judge and the subjectivity of human judgments. 2000 HINT responses were used from 25 listeners to develop a UVE based on hidden Markov models (HMMs), a lexicon of observed and likely words, and a grammar that generates utterances classifiable as correct or incorrect. An evaluation study is in progress with a planned enrollment of 25 normal-hearing listeners. HMMs, lexicon, and grammar are updated after every five listeners. In results with ten listeners tested to date, scoring accuracy averaged 88% per subject (range 81%–95%). The mean SRT determined by the UVE differed from the mean SRT determined by human scorers by an average of 0.56 dB (range 0.04–1.91). Complete results will be presented at the conference. [Work supported by NIDCD Grant R43DC008212.]

Noise susceptibility of cochlear implant users: the role of spectral resolution and smearing.

The latest-generation cochlear implant devices provide many deaf patients with good speech recognition in quiet listening conditions. However, speech recognition deteriorates rapidly as the level of background noise increases. Previous studies have shown that, for cochlear implant users, the absence of fine spectro-temporal cues may contribute to poorer performance in noise, especially when the noise is dynamic (e.g., competing speaker or modulated noise). Here we report on sentence recognition by cochlear implant users and by normal-hearing subjects listening to an acoustic simulation of a cochlear implant, in the presence of steady or square-wave modulated speech-shaped noise. Implant users were tested using their everyday, clinically assigned speech processors. In the acoustic simulation, normal-hearing listeners were tested for different degrees of spectral resolution (16, eight, or four channels) and spectral smearing (carrier filter slopes of -24 or -6 dB/octave). For modulated noise, normal-hearing listeners experienced significant release from masking when the original, unprocessed speech was presented (which preserved the spectro-temporal fine structure), while cochlear implant users experienced no release from masking. As the spectral resolution was reduced, normal-hearing listeners' release from masking gradually diminished. Release from masking was further reduced as the degree of spectral smearing increased. Interestingly, the mean speech recognition thresholds of implant users were very close to those of normal-hearing subjects listening to four-channel spectrally smeared noise-band speech. Also, the best cochlear implant listeners performed like normal-hearing subjects listening to eight- to 16-channel spectrally smeared noise-band speech. These findings suggest that implant users' susceptibility to noise may be caused by the reduced spectral resolution and the high degree of spectral smearing associated with channel interaction. Efforts to improve the effective number of spectral channels as well as reduce channel interactions may improve implant performance in noise, especially for temporally modulated noise.