Performance-intensity Functions Research Articles

Subjective Speech Intelligibility Drives Noise-Tolerance Domain Use During the Tracking of Noise-Tolerance Test.

Recently, the Noise-Tolerance Domains Test (NTDT) was applied to study the noise-tolerance domains used by young normal-hearing (NH) listeners during noise acceptance decisions. In this study, we examined how subjective speech intelligibility may drive noise acceptance decisions by applying the NTDT on NH and hearing-impaired (HI) listeners at the signal to noise ratios (SNRs) around the Tracking of Noise-Tolerance (TNT) thresholds. A single-blind, within-subjects design with 22 NH and 17 HI older adults was followed. Listeners completed the TNT to determine the average noise acceptance threshold (TNTAve). Then, listeners completed the NTDT at the SNRs of 0, ±3 dB (re: TNTAve) to estimate the weighted noise-tolerance domain ratings (WNTDRs) for each domain criterion. Listeners also completed the Objective and Subjective Intelligibility Difference (OSID) Test to establish the individual intelligibility performance-intensity (P-I) functions of the TNT materials. All test measures were conducted at 75 and 82 dB SPL speech input levels. NH and HI listeners were tested in the unaided mode. The HI listeners were also tested using a study hearing aid. The WNTDRs were plotted against subjective speech intelligibilities extrapolated from individual P-I of the OSID at the SNRs corresponding to NTDT test conditions. Listeners were grouped according to their most heavily weighed domain and a regression analysis was performed against listener demographics as well as TNT and OSID performances to determine which variable(s) affected listener grouping. Three linear mixed effects (LMEs) models were used to examine whether WNTDRs changed with subjective speech intelligibility. All three LMEs found significant fixed effects of domain criteria, subjective intelligibility, and speech input level on WNTDRs. In general, heavier weights were assigned to speech interference and loudness domains at poorer intelligibility levels (<50%) with reversals to distraction and annoyance at higher intelligibility levels (>80%). The comparison between NH and HI-unaided showed that NH listeners assigned greater weights to loudness than the HI-unaided listeners. The comparison between NH and HI-aided groups showed similar weights between groups. The comparison between HI-unaided and HI-aided found that HI listeners assigned lower weights to speech interference and greater weights to loudness when tested in aided compared with unaided modes. In all comparisons, loudness was weighed heavier at the 82 dB SPL input level than at the 75 dB SPL input level with greater weights to annoyance in the NH versus HI-unaided comparison and lower weights to distraction in the HI-aided versus HI-unaided comparison. A generalized linear model determined that listener grouping was best accounted for by subjective speech intelligibility estimated at TNTAve. The domain criteria used by listeners were driven by their subjective speech intelligibility regardless of their hearing status (i.e., NH versus HI). In general, when subjective intelligibility was poor, the domains of speech interference and loudness were weighed the heaviest. As subjective intelligibility improved, the weightings on annoyance and distraction increased. Furthermore, a listener's criterion for >90% subjective speech understanding at the TNTAve may allow one to profile the listener.

Chinese Emotional Speech Audiometry Project (CESAP): Establishment and Validation of a New Material Set With Emotionally Neutral Disyllabic Words.

The Chinese Emotional Speech Audiometry Project (CESAP) aims to establish a new material set for Chinese speech audiometry tests, which can be used in both neutral and emotional prosody settings. As the first endeavor of CESAP, this study demonstrates the development of the material foundation and reports its validation in neutral prosody. In the development step, 40 phonetically balanced word lists consisting of 30 Chinese disyllabic words with neutral valence were first generated. In a following affective rating experiment, 35 word lists were qualified for validation based on the familiarity and valence ratings from 30 normal-hearing (NH) participants. For validation, performance-intensity functions of each word list were fitted with responses from 60 NH subjects under six presentation levels (-1, 3, 5, 7, 11, and 20 dB HL). The final material set was determined by the intelligibility scores at each decibel level and the mean slopes. First, 35 lists satisfied the criteria of phonetic balance, limited repetitions, high familiarity, and neutral valence and were selected for validation. Second, 15 lists were compiled in the final material set based on the pairwise differences in intelligibility scores and the fitted 20%-80% slopes. The established material set had high reliability and validity and was sensitive to detect intelligibility changes (50% slope: 6.20%/dB; 20%-80% slope: 5.45%/dB), with small covariance of variation for thresholds (15%), 50% slope (12%), and 20%-80% slope (12%). Our final material set of 15 word lists takes the initiative to control the emotional aspect of audiometry tests, which enriches available Mandarin speech recognition materials and warrants future assessments in emotional prosody among populations with hearing impairments. https://doi.org/10.23641/asha.25742814.

Speech intelligibility and its relation to auditory temporal processing in Czech and Swiss German subjects with and without tinnitus.

Previous studies have shown that levels for 50% speech intelligibility in quiet and in noise differ for different languages. Here, we aimed to find out whether these differences may relate to different auditory processing of temporal sound features in different languages, and to determine the influence of tinnitus on speech comprehension in different languages. We measured speech intelligibility under various conditions (words in quiet, sentences in babble noise, interrupted sentences) along with tone detection thresholds in quiet [PTA] and in noise [PTAnoise], gap detection thresholds [GDT], and detection thresholds for frequency modulation [FMT], and compared them between Czech and Swiss subjects matched in mean age and PTA. The Swiss subjects exhibited higher speech reception thresholds in quiet, higher threshold speech-to-noise ratio, and shallower slope of performance-intensity function for the words in quiet. Importantly, the intelligibility of temporally gated speech was similar in the Czech and Swiss subjects. The PTAnoise, GDT, and FMT were similar in the two groups. The Czech subjects exhibited correlations of the speech tests with GDT and FMT, which was not the case in the Swiss group. Qualitatively, the results of comparisons between the Swiss and Czech populations were not influenced by presence of subjective tinnitus. The results support the notion of language-specific differences in speech comprehension which persists also in tinnitus subjects, and indicates different associations with the elementary measures of auditory temporal processing.

Development and evaluation of Tamil Matrix Sentence Test Performance in young adults.

The purpose of the study was to develop the Tamil Matrix Sentence Test (TMST) and evaluate the performance of a group of young adults with normal hearing on the developed test. The developed sentences were also administered at varying intensities to obtain a performance-intensity (PI) function. A base matrix with 10 sentences containing 5 words each with a total of 50 words was used to develop the TMST. The sentences had a fixed semantic sentence structure of Tamil language in the order of noun, number, adjective, object and verb. The developed test consisted of 30 lists with 10 sentences in each list. The performance of 60 young adults with normal hearing aged 18 to 24 years across the 30 lists were compared for list equivalency. To obtain the PI function the sentences were administered on 20 young adults with normal hearing at intensities from 20 dB HL to 100 dB HL in 10 dB increments. The performance across the intensity levels were compared. The 30 lists of TMST were found to be acoustically equivalent. However, few lists showed significant difference in the scores obtained on them compared to the rest of the lists. The PI function revealed a saturation in performance beyond 40 dB HL. From the results it was construed that TMST can be used to evaluate the speech identification abilities of Tamil speaking listeners. Multiple lists offer the advantage of retesting without the influence of practice or listeners memorizing the test material.

Amplitude Compression for Preventing Rollover at Above-Conversational Speech Levels.

Hearing aids provide nonlinear amplification to improve speech audibility and loudness perception. While more audibility typically increases speech intelligibility at low levels, the same is not true for above-conversational levels, where decreases in intelligibility ("rollover") can occur. In a previous study, we found rollover in speech intelligibility measurements made in quiet for 35 out of 74 test ears with a hearing loss. Furthermore, we found rollover occurrence in quiet to be associated with poorer speech intelligibility in noise as measured with linear amplification. Here, we retested 16 participants with rollover with three amplitude-compression settings. Two were designed to prevent rollover by applying slow- or fast-acting compression with a 5:1 compression ratio around the "sweet spot," that is, the area in an individual performance-intensity function with high intelligibility and listening comfort. The third, reference setting used gains and compression ratios prescribed by the "National Acoustic Laboratories Non-Linear 1" rule. Speech intelligibility was assessed in quiet and in noise. Pairwise preference judgments were also collected. For speech levels of 70 dB SPL and above, slow-acting sweet-spot compression gave better intelligibility in quiet and noise than the reference setting. Additionally, the participants clearly preferred slow-acting sweet-spot compression over the other settings. At lower levels, the three settings gave comparable speech intelligibility, and the participants preferred the reference setting over both sweet-spot settings. Overall, these results suggest that, for listeners with rollover, slow-acting sweet-spot compression is beneficial at 70 dB SPL and above, while at lower levels clinically established gain targets are more suited.

Development of Phonemically Balanced Word List in Tamil for Speech Audiometry and Evaluation of Its Effectiveness in Adults.

Speech audiometry has become an essential component of the audiological test battery. Various speech audiometry materials have been developed in different languages and also revised later to meet criteria such as familiarity of the words, phonetic/phonemic balance, number of test items, and dialectal variations. The current study focused on developing a PB word list in Tamil for adults. The study was carried out in two phases. Phase I involved the development of a PB word list in Tamil. Phase II included evaluating the effectiveness of the developed word lists on adults with normal hearing sensitivity and hearing impairment. A total of 500 bisyllabic words were used in creating a master list. The collected words were subjected to familiarity testing with 40 native Tamil speakers. From the master list of 500 words, 90% of the participants rated 320 words as most familiar, and those words were included in the study. The 320 words were validated by eight experts working in the fields of audiology, speech-language pathology, linguistics, and psychology. The disagreed-with words were excluded from the list, and only 270 words that were agreed upon by all the experts were included in the final list. The final lists comprised four-word lists with 25 phonetically balanced (PB) words per list. The final word lists were recorded and tested for goodness. These final words were then administered to find SIS scores for two groups. Group I consisted of adults with 120 normal hearing sensitivity, and Group II consisted of 130 adults with hearing impairment. The results were analysed using SPSS software. The mean SIS in adults with normal hearing sensitivity ranged from 99.4 to 99.8%. The SIS of adults with normal hearing sensitivity revealed no significant difference (p > .05) with respect to gender, ears, or across the four-word lists. All four-word lists provided similar scores, establishing the equivalency of word lists in individuals with normal hearing sensitivity as well as hearing impairment. A psychometric curve of performance intensity function in adults with normal hearing sensitivity revealed that the SIS score increased as the sensation level increased from 10 to 40dBSL. There is a linear increase in SIS scores from 10 to 20dBSL. A plateau was attained at 40dBSL with 100% SIS scores. Thus, the present study recommends the use of 40dB SL for SIS testing. Mean SIS scores for adults with mild, moderate, and severe hearing loss were found to be 90.1%, 65.4%, and 41.8%, respectively. A significant decrease in SIS was observed as the degree of hearing loss increased.

Measuring Objective and Subjective Intelligibility Using Speech Materials from the Tracking of Noise Tolerance (TNT) Test.

The results of tests measuring objective speech intelligibility are similar to those measuring subjective speech intelligibility using speech materials with minimal context. It is unclear if such is the case with contextual materials. This article compares objective and subjective intelligibility difference (OSID) between normal hearing (NH) and hearing impaired (HI) listeners in the unaided and aided modes using speech materials adapted from the Tracking of Noise Tolerance (TNT) test. Single-blind within-subjects design. Twenty-four NH and 17 HI older adults. Listeners completed the objective and subjective intelligibility measures at 75 and 82 dB sound pressure level (SPL) speech input levels. Five signal-to-noise ratios were tested to generate the objective and subjective speech intelligibility performance intensity (P-I) functions. Both NH and HI listeners were tested in the unaided mode. The HI listeners were also tested using their own hearing aids (HAs). Objective and subjective speech reception thresholds at a 50% criterion (SRT50s) were estimated from each individual P-I function. The difference between the objective SRT50 and subjective SRT50 was used to estimate OSID. Objective and subjective SRT50s were significantly better in NH than in HI listeners (chi-square(1) = 26.29, p < 0.001) at each speech input level in the unaided mode. However, there was a significant interaction between listener group and intelligibility type (chi-square(1) = 9.43, p = 0.002) where SRT50s were lower for subjective than objective P-I functions only in the HI group. The SRT50s of HI listeners were also affected by hearing mode, where both objective and subjective intelligibility was improved when HI listeners were tested while wearing their own HAs. In general, objective and subjective SRT50s showed moderate-to-strong correlations across most combinations of listener groups and test conditions (r = 0.59-0.86, p < 0.01) except for HI listeners tested with their own HAs (r = 0.39, p = 0.128). Similar objective and subjective intelligibility was observed in NH listeners but better subjective intelligibility than objective intelligibility was noted in HI listeners when tested in the unaided and aided modes.

The German hearing in noise test with a female talker: development and comparison with German male speech test

PurposeThe aim of the study was to develop the German Hearing in Noise Test (HINT) with female speaker by fulfilling the recommendations by International Collegium of Rehabilitative Audiology (ICRA) for using a female speaker to create new multilingual speech tests and to determine norms and to compare these norms with German male speech tests—the male speakers HINT and the Oldenburg Sentence Test (OLSA).MethodsThe HINT with a female speaker consists of the same speech material as the male speaking HINT. After recording the speech material, 10 normal hearing subjects were included to determine the performance–intensity function (PI function). 24 subjects were part of the measurements to determine the norms and compare them with the norms of male HINT and OLSA. Comparably, adaptive, open-set methods under headphones (HINT) and sound field (OLSA) were used.ResultsAcoustic phonetic analysis demonstrated significant difference in mean fundamental frequency, its range and mean speaking rate between both HINT speakers. The calculated norms by three of the tested four conditions of the HINT with a female speaker are not significantly different from the norms with a male speaker. No significant effect of the speaker’s gender of the first HINT measurement and no significant correlation between the threshold results of the HINT and the OLSA were determined.ConclusionsThe Norms for German HINT with a female speaker are comparable to the norms of the HINT with a male speaker. The speech intelligibility score of the HINT does not depend on the speakers’ gender despite significant difference of acoustic–phonetic parameters between the female and male HINT speaker’s voice. Instead, the speech intelligibility rating must be seen as a function of the used speech material.

Predicting Aided Outcome With Aided Word Recognition Scores Measured With Linear Amplification at Above-conversational Levels.

Many hearing aid (HA) users receive limited benefit from amplification, especially when trying to understand speech in noise, and they often report hearing-related residual activity limitations. Current HA fitting strategies are typically based on pure-tone hearing thresholds only, even though suprathreshold factors have been linked to aided outcomes. Furthermore, clinical measures of speech perception such as word recognition scores (WRSs) are performed without frequency-specific amplification, likely resulting in suboptimal speech audibility and thus inaccurate estimates of suprathreshold hearing abilities. Corresponding measures with frequency-specific amplification ("aided") would likely improve such estimates and enable more accurate aided outcome prediction. Here, we investigated potential links between either unaided WRSs or aided WRSs measured at several above-conversational levels and two established HA outcome measures: The Hearing-In-Noise Test (HINT) and the International Outcome Inventory for Hearing Aids (IOI-HA). Thirty-seven older individuals with bilateral hearing impairments participated. Two conditions were tested: unaided and aided, with all stimuli presented over headphones. In the unaided condition, the most comfortable level (MCL) for the presented speech stimuli, WRS at MCL+10 dB as well as uncomfortable levels (UCLs) for narrowband noise stimuli were measured. In the aided condition, all stimuli were individually amplified according to the "National Acoustic Laboratories-Revised, Profound" fitting rule. Aided WRSs were then measured using an Interacoustics Affinity system at three above-conversational levels, allowing for the maximum aided WRS as well as the presence of "rollover" in the performance-intensity function to be estimated. Multivariate data analyses were performed to examine the relations between the HINT (measured using a simulated HA with the NAL-RP amplification) or IOI-HA scores (for the participants' own HAs) and various potential predictors (age, pure-tone average hearing loss, unaided WRS, aided WRS, rollover presence [ROp], and UCL). Aided WRSs predicted the HINT scores better than any other predictor and were also the only significant predictor of the IOI-HA scores. In addition, UCL and ROp in the aided WRSs were significant predictors of the HINT scores and competed for variance in the statistical models. Neither age nor pure-tone average hearing loss could predict the two aided outcomes. Aided WRSs can predict HA outcome more effectively than unaided WRSs, age or pure-tone audiometry and could be relatively easily implemented in clinical settings. More research is necessary to better understand the relations between ROp, UCL and speech recognition at above-conversational levels.

Validation of Male Talker Recordings of the Spanish Pediatric Speech Recognition Threshold Test and the Spanish Pediatric Picture Identification Test.

The purpose of this study was to validate recordings of the Spanish Pediatric Speech Recognition Threshold (SPSRT) test and Spanish Pediatric Picture Identification Test (SPPIT) for Spanish-speaking children using a native, bilingual Spanish-English male talker of Castilian peninsular dialect from Spain. Seventy native Spanish-speaking children from a variety of countries participated. Fifty-eight participants had normal hearing, and the remaining 12 had mild hearing loss in at least one ear. Male talker recordings of the SPSRT and SPPIT were administered to obtain baseline validation data. Participants listened to the stimuli and pointed to the appropriate item on the picture boards that represented the word they heard. Mean SRTs were within 5 dB of mean pure-tone averages resulting in a positive correlation. Performance-intensity functions for the SPPIT showed minimal significant differences across the three test lists, and performance increased as the sensation level increased. The male talker recordings of the SPSRT and SPPIT are valid speech perception picture-pointing assessments that can be used with Spanish-speaking children. The recordings present the Spanish target word while simultaneously presenting the English interpretation for ease of scoring.

Phonemically Balanced Arabic Monosyllabic Word Lists for Speech Audiometry Testing in Jordan.

Many of the Arabic monosyllabic word lists that are currently available in the literature have some limitations and drawbacks. Some of these available lists include word structures that are not consonant-nucleus-consonant (CNC) such as cluster and disyllabic word structures. Other lists have poor phonetic or phonemic distribution balance and do not represent some phoneme appropriately in each list. The purpose of the present study is to create and validate eight digitally recorded lists of phonemically balanced CNC words that represent all Arabic phonemes, to be used in the evaluation of word recognition score (WRS) of Jordanian Arabic-speaking adults. These lists should be easily adapted by other Arab countries because of the simplicity of the words, and the balanced inclusion of all the Arabic phonemes. The present study is a prospective cross-sectional study. Thirty-one (23 females, 8 males) normal hearing and healthy young adults (18-29 years old) participated in the present study. All participants were native speakers of Jordanian Arabic and had no history of ear disease or surgery. The authors created all possible combinations of Arabic CNC words, and then created eight phonemically balanced lists with 26 words in each list. Each consonant was presented only once at the beginning of a word and once at the end of a word in each list. The lists were recorded using a Jordanian male voice and the intensity of each word was digitally calibrated. The pure tone average (PTA) of 0.5, 1, 2, 4 kHz was calculated for each participant, and the WRS was obtained for each intensity level in the range of -10 to 55 dB SL (ref. PTA) in 5 dB steps. No significant difference between right and left ear WRS was found at any intensity level. The WRSs from both ears were averaged and used in the repeated measure analysis of variance. Performance-intensity functions for all the lists showed some small but statistically significant differences between lists. However, none of these differences were clinically significant (<4%). All the lists showed WRS exceeding 96% at 40 dB SL, and none of the lists showed statistically significant improvement in WRS beyond 40 dB SL. The present study provides eight lists of recorded and calibrated CNC word lists. The obtained PI functions showed that these lists are suitable for Jordanian Arabic speaking adults. These lists can be easily generalized to other Arab countries after conducting the required follow-up research.

Development of the Mandarin Nonsense Word Identification Test

Objective This study aimed to develop a digitised Mandarin Nonsense Word Speech Perception Test for use in Malaysia, a multilingual country in Southeast Asia. Design In Phase I, 400 vowel-consonant-vowel (VCV) nonsense word samples containing 20 Mandarin consonants in /a/, /i/, or /u/ contexts were recorded from two speakers of different genders. Acoustic analyses, sound quality ratings, and item validations were used to guide selection of items to form two gender-specific test lists. In Phase II, performance-intensity functions and test-retest reliability for the lists were established. Study sample Native Mandarin-speaking adults with normal hearing participated in Phase I (n = 10) and Phase II (n = 69). Results Eighty-four of the 400 VCV words were selected to form two gender-specific test lists. A two-way repeated measure ANOVA revealed a significant interaction effect between speaker-gender and presentation level [F (4.88, 283.20) = 22.79, p < 0.001, ηp 2= 0.28]. Intraclass correlation scores of 0.75 and 0.87 were obtained for the female-speaker and male-speaker lists respectively. Conclusions The preliminary normative data of the Mandarin nonsense word test have been developed. It is recommended to use separate gender-specific norms when conducting the test. The test has good validity and reliability for testing Mandarin-speaking adults in Malaysia.

Comparison of real-ear insertion gains in Japanese-speaking individuals wearing hearing aids with DSLv5 and NAL-NL2

ObjectiveWe used real-ear insertion gain (REIG), with the international speech test signal (ISTS), to evaluate the amplifying characteristics of hearing aids, set for patients who have been wearing such aids for a long time in a stable manner. We further compared this to the target values of the DSLv5 and NAL-NL2 methods. MethodsThe subjects were adults with moderate sensorineural hearing loss. We examined 40 ears in 25 individuals (15 people wearing hearing aids in both ears and ten people wearing aid in only one ear). Fit assessments were performed based on the speech performance-intensity functions and tolerance of environmental noise, and the ears studied were categorized as either ears with sufficient benefit or ears with insufficient benefit. Additionally, we evaluated the REIG for international speech test signals at 65-dB and 80-dB sound pressure level (SPL). We compared the REIG and target values for voice input at 65-dB and 80-dB SPL, calculated from the DSLv5 and NAL-NL2 methods. ResultsAmong the 40 ears, 34 received sufficient benefit and six received an insufficient benefit from hearing aids. The REIG for ISTS at 65-dB in the sufficient benefit ears, at frequencies of 1,000 Hz and 2,000 Hz, were similar to the target values of NAL-NL2 and DSLv5 but were significantly lower at 250 Hz, 500 Hz, and 4,000 Hz frequencies. The compression ratio of REIG for sufficient benefit ears was similar to that of DSLv5. The REIG for ISTS at 65-dB in the insufficient benefit ears was smaller than that in the sufficient benefit ears at frequencies of 2,000 Hz and 4,000 Hz. ConclusionThis study suggested that the target values of NAL-NL2 and DSLv5 are appropriate, even for Japanese-speaking individuals, at mid-pitch sounds. Although it is necessary to investigate the necessity for low-pitch and high-pitch gains further in the future, this study provides meaningful data regarding the amplifying characteristics in Japanese-speaking individuals who have been wearing hearing aids in a stable manner.

Spanish Pediatric Picture Identification Test.

Purpose The purpose of this study was to construct and validate a recorded word recognition test for monolingual Spanish-speaking children utilizing a picture board and a picture-pointing task. Design The Spanish Pediatric Picture Identification Test was developed and validated in this study. Test construction steps included (a) producing new digital recordings of word lists created by Comstock and Martin (1984) using a bilingual Spanish-English female, (b) obtaining list equivalency, (c) creating digitally illustrated pictures representing the word lists, (d) validating the pictures using monolingual Spanish-speaking and bilingual Spanish-English children, and (e) re-establishing list equivalency and obtaining performance-intensity functions using a picture-pointing task with monolingual Spanish-speaking children and bilingual Spanish-English adults. Results Normative data for three Spanish word recognition lists were established. Performance-intensity functions at sensation levels from 0 to 40 dB SL in 8-dB steps were obtained, establishing list equivalency for Lists 1, 2, and 3. Conclusions The Spanish Pediatric Picture Identification Test was developed and validated as a picture-pointing task for word recognition with monolingual Spanish-speaking children. The two validated channel recordings include an English translation for ease of testing by clinicians lacking Spanish language skills. Future validation will be conducted with bilingual Spanish-English children with normal hearing and with hearing loss.

The characteristics of monosyllable recognition in Mandarin-speaking patients with auditory neuropathy

Background: A set of Chinese Mandarin monosyllable test lists has been widely used in clinical diagnosis, while the performance of the Mandarin-speaking patients with auditory neuropathy (AN) in the monosyllable tests was still unknown.Objectives: To analyze the characteristics of monosyllable recognition in Mandarin-speaking patients with AN.Materials and methods: Nineteen Mandarin-speaking patients diagnosed with AN were recruited to obtain the performance-intensity (P-I) functions. They were divided into two paired groups according to two conditions: (1) the rising-slope (RS) and the non-rising-slope pattern (NRS) group for the audiogram; or (2) the male and the female group for gender.Results: The performance at 20 and 30 dB SL showed negative correlation with the pure tone-averaged thresholds of 0.5, 1.0, 2.0 and 4.0 kHz (4FA). We found significant differences between the P-I functions of the RS and the NRS group, and surprisingly found that between the male and female as well although there was no difference in 4FA between the paired groups. A notable rollover phenomenon in P-I functions was detected in each group.Conclusions: The monosyllable recognition scores of Mandarin-speaking AN patients showed numerous particular characteristics reflected by P-I functions. Acquiring the complete P-I functions at multiple presentation levels and the rollover index may give us more information about the diagnosis and prognosis.

Performance-intensity functions of Mandarin fricative-affricate nonsense word test: preliminary findings

ABSTRACT Purpose: Mandarin speech perception tests are scarce in Malaysia. Speech perception tests developed in other Mandarin-speaking countries are not suitable for local use due to colloquial and cultural differences. A previous study developed a digitally recorded nonsense word test that emphasizes Mandarin sibilant fricatives and affricates. However, no performance-intensity function has been established for the test. This study aimed to establish and compare the baseline performance-intensity function of the nonsense word lists between speaker genders. Method: Native Mandarin-speaking young adults with normal hearing (n = 55) participated in this study. Test stimuli were two lists of nonsense words recorded from a male and a female speaker. Each list has 18 vowel-consonant-vowel nonsense words. During testing, each list was presented monaurally to participants via insert-earphones at seven intensity levels in 5 dB-step decrements. The sequence of speaker genders and the nonsense words within each list was randomized. The identification scores of participants were measured. Results: A two-way repeated-measure ANOVA revealed that there is a significant interaction effect between speaker genders and intensity levels. Pairwise comparisons showed significant differences in identification scores between 0, 5, 15, and 20 dB HL for nonsense words of both speaker genders. However, no significant difference was found between pairs of 20, 25, and 30 dB HL. Different speaker gender lists yielded similar results. Conclusion: Performance-intensity function was developed for the Mandarin fricative-affricate nonsense word test. The test has the potential to be used as a speech audiometry test in local clinics.

Frequency characteristics and speech recognition in cartilage conduction

ObjectiveCartilage conduction (CC) is a new transduction form, and hearing devices that utilize CC present a new option for patients with aural atresia. However, in occluded ears, low-tone sounds are transmitted very effectively, resulting in excessive low-tone sound emphasis and speech recognition reduction. This study aimed to clarify low-tone speech recognition for CC in occluded ears, and determine if excessive low-tone sound emphasis decreases maximum speech recognition scores. MethodsEight volunteers with normal hearing participated. The performance-intensity function and maximum speech recognition scores for CC with an earplug (i.e., occluded) and air conduction (AC) were measured under high- and low-pass filter (HPF and LPF) conditions, respectively. ResultsAn HPF improved the maximum speech recognition scores for CC in occluded ears. The scores for CC (occluded) under the conditions of the first- and second-order HPF did not differ from that for AC under the no-filter condition. Conversely, an LPF reduced the scores for AC. The scores and confusion matrices under the second-order LPF condition were similar to those for CC (occluded). ConclusionThe conditions under the second-order LPF resembled those of CC in occluded ears. An HPF can compensate excessive low-tone emphasis and improve speech recognition.

Using Microphone Technology to Improve Speech Perception in Noise in Children with Cochlear Implants.

Cochlear implant (CI) users are affected more than their normal hearing (NH) peers by the negative consequences of background noise on speech understanding. Research has shown that adult CI users can improve their speech recognition in challenging listening environments by using dual-microphone beamformers, such as adaptive directional microphones (ADMs) and wireless remote microphones (RMs). The suitability of these microphone technologies for use in children with CIs is not well-understood nor widely accepted. To assess the benefit of ADM or RM technology on speech perception in background noise in children and adolescents with cochlear implants (CIs) with no previous or current use of ADM or RM. Mixed, repeated measures design. Twenty (20) children, ten (10) CI users (mean age 14.3 yrs) who used Advanced Bionics HiRes90K implants with research Naida processors, and ten (10) NH age-matched controls participated in this prospective study. CI users listened with an ear-canal level microphone, T-Mic (TM), an ADM, and a wireless RM at different audio-mixing ratios. Speech understanding with five microphone settings (TM 100%, ADM, RM + TM 50/50, RM + TM 75/25, RM 100%) was evaluated in quiet and in noise. Speech perception ability was measured using children's spondee words to obtain a speech recognition threshold for 80% accuracy (SRT80%) in 20-talker babble where the listener sat in a sound booth 1 m (3.28') from the target speech (front) and noise (behind) to test five microphone settings (TM 100%, ADM, RM + TM 50/50, RM + TM 75/25, RM 100%). Group performance-intensity functions were computed for each listening condition to show the effects of microphone configuration with respect to signal-to-noise ratio (SNR). A difference score (CI Group minus NH Group) was computed to show the effect of microphone technology at different SNRs relative to NH. Statistical analysis using a repeated-measures analysis of variance evaluated the effects of the microphone configurations on SRT80% and performance at SNRs. Between-groups analysis of variance was used to compare the CI group with the NH group. The speech recognition was significantly poorer for children with CI than children with NH in quiet and in noise when using the TM alone. Adding the ADM or RM provided a significant improvement in speech recognition for the CI group over use of the TM alone in noise (mean dB advantage ranged from 5.8 for ADM to 16 for RM100). When children with CI used the RM75 or RM100 in background babble, speech recognition was not statistically different from the group with NH. Speech recognition in noise performance improved with the use of ADM and RM100 or RM75 over TM-only for children with CIs. Alhough children with CI remain at a disadvantage as compared with NH children in quiet and more favorable SNRs, microphone technology can enhance performance for some children with CI to match that of NH peers in contexts with negative SNRs.

Modernising speech audiometry: using a smartphone application to test word recognition

Objective: This study aimed to develop and assess a method to measure word recognition abilities using a smartphone application (App) connected to an audiometer.Design: Word lists were recorded in South African English and Afrikaans. Analyses were conducted to determine the effect of hardware used for presentation (computer, compact-disc player, or smartphone) on the frequency content of recordings. An Android App was developed to enable presentation of recorded materials via a smartphone connected to the auxiliary input of the audiometer. Experiments were performed to test feasibility and validity of the developed App and recordings.Study sample: Participants were 100 young adults (18–30 years) with pure tone thresholds ≤15 dB across the frequency spectrum (250–8000 Hz).Results: Hardware used for presentation had no significant effect on the frequency content of recordings. Listening experiments indicated good inter-list reliability for recordings in both languages, with no significant differences between scores on different lists at each of the tested intensities. Performance-intensity functions had slopes of 4.05%/dB for English and 4.75%/dB for Afrikaans lists at the 50% point.Conclusions: The developed smartphone App constitutes a feasible and valid method for measuring word recognition scores, and can support standardisation and accessibility of recorded speech audiometry.

Clinical Strategies for Sampling Word Recognition Performance

Computer simulation was used to estimate the statistical properties of searches for maximum word recognition ability (PB max). These involve presenting multiple lists and discarding all scores but that of the 1 list that produced the highest score. The simulations, which model limitations inherent in the precision of word recognition scores, were done to inform clinical protocols. A secondary consideration was a derivation of 95% confidence intervals for significant changes in score from phonemic scoring of a 50-word list. The PB max simulations were conducted on a "client" with flat performance intensity functions. The client's performance was assumed to be 60% initially and 40% for a second assessment. Thousands of estimates were obtained to examine the precision of (a) single lists and (b) multiple lists using a PB max procedure. This method permitted summarizing the precision for assessing a 20% drop in performance. A single 25-word list could identify only 58.4% of the cases in which performance fell from 60% to 40%. A single 125-word list identified 99.8% of the declines correctly. Presenting 3 or 5 lists to find PB max produced an undesirable finding: an increase in the word recognition score. A 25-word list produces unacceptably low precision for making clinical decisions. This finding holds in both single and multiple 25-word lists, as in a search for PB max. A table is provided, giving estimates of 95% critical ranges for successive presentations of a 50-word list analyzed by the number of phonemes correctly identified.