Speech Perception Research Articles

Segmentation window of speech information processing in the human auditory cortex

Humans perceive continuous speech signals as discrete sequences. To clarify the temporal segmentation window of speech information processing in the human auditory cortex, the relationship between speech perception and cortical responses was investigated using auditory evoked magnetic fields (AEFs). AEFs were measured while participants heard synthetic Japanese words /atataka/. There were eight types of /atataka/ with different speech rates. The durations of the words ranged from 75 to 600 ms. The results revealed a clear correlation between the AEFs and syllables. Specifically, when the durations of the words were between 375 and 600 ms, the evoked responses exhibited four clear responses from the superior temporal area, M100, that corresponded not only to the onset of speech but also to each group of consonant/vowel syllable units. The number of evoked M100 responses was correlated to the duration of the stimulus as well as the number of perceived syllables. The approximate range of the temporal segmentation window limit of speech perception was considered to be between 75 and 94 ms. This finding may contribute to optimizing the temporal performance of high-speed synthesized speech generation systems.

Audiological and Subjective Benefits in a Child with Microtia and Atresia After Sequential Bilateral Implantation with Active Bone Conduction Devices: A Case Study

Background: With bilateral hearing loss, the main problems for the patient are speech understanding in noise and, especially in asymmetrical hearing loss, an inability to correctly localize sound sources. There are multiple methods of treatment and rehabilitation for people with conductive hearing loss, and one of them is to use an active bone conduction implant. This case study is designed to evaluate the auditory benefits and sound localization accuracy with active bilateral bone conduction implants—in comparison to unilateral ones—in a patient with congenital bilateral conductive hearing loss caused by a congenital malformation. We assess subjective and audiological benefits (functional, directional hearing, speech comprehension in quiet and noise). Case report: This study describes the results in a 15-year-old patient with bilateral congenital malformation of the outer ears and associated conductive hearing loss who was treated with two Bonebridge active bone conduction implants. Speech recognition ability, hearing thresholds, and sound localization were tested under three conditions: unaided, unilateral on the right-side, and bilateral on both sides. The patient filled in an Abbreviated Profile of Hearing Aid Benefit questionnaire (APHAB) to evaluate limitations in daily life caused by hearing impairment. The results show an improvement in free-field hearing thresholds and the ability to discriminate speech, both in quiet and in noise after implantation. Subjectively, the patient had significantly fewer problems with two implants than with one (or with no implant) in terms of hearing in everyday situations. Conclusions: Unilateral use of the Bonebridge device in a patient with congenital bilateral conductive hearing loss did not provide full benefits. However, bilateral implantation improved speech understanding in noise and sound localization.

A comparison of Heritage vs Homeland Taiwanese Mandarin speaker attitudes towards sajiao

This study investigates the language attitudes and perceptions of Taiwanese Mandarin heritage and homeland listeners towards the use of sajiao, a stylized speech type, in two varieties of Mandarin. A matched guise experiment was conducted via Qualtrics with heritage listeners from the United States (n = 6) and homeland listeners from Taiwan (n = 7). Participants listened to a recording and rated their perceived social constructions of the speakers in terms of their cuteness, pleasantness, femininity, masculinity, and professionalism on a scale from one to seven. In total, participants listened to 130 recordings, 64 target and 66 filler, of 4 different sentences with both sajiao and non-sajiao forms. We find that heritage speakers pattern similarly to homeland speakers, although not to the same extent. This positions heritage speakers in their own category, where they have acquired the social associations with this specialized speech style, but not to the same degree as homeland speakers. This research sheds new light on heritage language socialization and perceptions of language variation, namely regarding two varieties of Mandarin and speech style. Further research is needed to investigate how Beijing Mandarin heritage speakers would perform in this same task.

Cortical Tracking of Speech Is Reduced in Adults Who Stutter When Listening for Speaking.

The purpose of this study was to investigate cortical tracking of speech (CTS) in adults who stutter (AWS) compared to typically fluent adults (TFAs) to test the involvement of the speech-motor network in tracking rhythmic speech information. Participants' electroencephalogram was recorded while they simply listened to sentences (listening only) or completed them by naming a picture (listening for speaking), thus manipulating the upcoming involvement of speech production. We analyzed speech-brain coherence and brain connectivity during listening. During the listening-for-speaking task, AWS exhibited reduced CTS in the 3- to 5-Hz range (theta), corresponding to the syllabic rhythm. The effect was localized in the left inferior parietal and right pre/supplementary motor regions. Connectivity analyses revealed that TFAs had stronger information transfer in the theta range in both tasks in fronto-temporo-parietal regions. When considering the whole sample of participants, increased connectivity from the right superior temporal cortex to the left sensorimotor cortex was correlated with faster naming times in the listening-for-speaking task. Atypical speech-motor functioning in stuttering impacts speech perception, especially in situations requiring articulatory alertness. The involvement of frontal and (pre)motor regions in CTS in TFAs is highlighted. Further investigation is needed into speech perception in individuals with speech-motor deficits, especially when smooth transitioning between listening and speaking is required, such as in real-life conversational settings. https://doi.org/10.23641/asha.27234885.

Neuroimaging Findings for the Overnight Consolidation of Learned Non-native Speech Sounds

Abstract Research over the past two decades has documented the importance of sleep to language learning. Sleep has been suggested to play a role in establishing new speech representations as well; however, the neural mechanisms corresponding to sleep-mediated effects on speech perception behavior are unknown. In this study, we trained monolingual English-speaking adults to perceive differences between the Hindi dental vs. retroflex speech contrast in the evening. We examined the blood oxygen level dependent signal using functional magnetic resonance imaging during perceptual tasks on both the trained talker and on an untrained talker shortly after training, and again the next morning. We also employed diffusion tensor imaging to determine if individual differences in white matter structure could predict variability in overnight consolidation. We found greater activity in cortical regions associated with language processing (e.g., left insula) on the second day. Fractional anisotropy values in the anterior thalamic radiation and the uncinate fasciculus was associated with the magnitude of overnight change in perceptual behavior on the generalization (untrained) talker, after controlling for differences in sleep duration and initial learning. Our findings suggest that speech-perceptual information is subject to an overnight transfer of information to the cortex. Moreover, neural structure appears to be linked to individual differences in efficiency of overnight consolidation.

Community Perspectives on Psychological Assessment Reports for Autistic Young Adults.

Clinicians rarely solicit community feedback on psychological assessment reports. This study addresses this knowledge gap to: (1) improve the usefulness of reports for patients and families, (2) increase access to needed services, and (3) make reports accessible for autistic people and their families. An autistic researcher and a non-autistic researcher jointly conducted qualitative interviews with autistic young adults, caregivers, and a service provider. Participants read a de-identified psychological assessment report about an autistic young adult with intellectual disability seeking resources for his transition to adulthood. Participants provided feedback about (1) how easy the report was to read, (2) how useful the report seemed, and (3) perceptions of language (i.e., empowering/offensive/neutral). Autistic young adults, caregivers, and the service provider all expressed a desire for short and clear reports in bulleted format. Caregivers stressed the importance of (1) using simple language to describe diagnostic testing and (2) including comprehensive resources, and autistic young adults expressed the importance of (1) including information about daily routines, habits, and interests and (2) giving patients' long-term goals the same consideration as caregivers' long-term goals. We highlight that standard psychological assessment reports have not effectively met the needs of autistic people and family members. Autistic people and caregivers prefer brief reports written in plain language that include more information about the patients' interests, routines, and preferences and less detailed information about psychological tests. Our findings identify ways to improve the usefulness and readability of psychological assessment reports for autistic people.

Clinical Outcomes for Adult Single-Sided Deafness Cochlear Implantees Exceeding the 5% Candidacy Criterion

Objectives: While single-sided deafness cochlear implants (SSD-CIs) have now received regulatory approval in the United States, candidate-ear candidacy criteria (no better than 5% word-recognition score) are stricter than for traditional CI candidates (50 to 60% speech recognition, best-aided condition). SSD implantation in our center began before regulatory approval, using a criterion derived from traditional candidacy: 50% consonant-nucleus-consonant (CNC) word-identification score in the candidate ear. A retrospective analysis investigated whether SSD patients exceeding the 5% CNC criterion nevertheless benefitted from a CI as assessed by spatial-hearing tests (speech understanding in noise [SIN] and localization) and by a patient-reported outcome measure quality-of-life instrument validated for patients with CIs. Design: A retrospective chart review assessed the clinical experience of a single CI center. Subjects consisted of 27 adult CI recipients with SSD (N = 21) or asymmetric hearing loss (AHL; N = 6) implanted since September 2019 with at least 3 months of postoperative follow-up. Patients with revision surgery or simultaneous labyrinthectomy and CI surgery were excluded from the sample. Subjects were divided into 2 groups based on preoperative CNC scores measured under best-aided conditions with a behind-the-ear hearing aid in the sound field at 0.9 m from a front loudspeaker, and the better ear masked using an insert earphone with 45 dB HL speech-weighted noise. The “MEETS” group had preoperative CNC word scores <5%; the “EXCEEDS” group had scores >5%. The clinical protocol also included intelligibility tests using AzBio sentences in the same test conditions as CNC; binaural spatial testing (broadband-noise sound localization, and matrix-sentence speech-reception thresholds in spatially separated noise) using a custom-built 7-speaker array; and the CI Quality of Life (CIQOL) instrument. To evaluate CI benefit, preoperative unaided performance was compared with postoperative binaural (acoustic ear + CI ear) performance at a clinic visit closest to 6 months postsurgery. Results: Of 27 SSD-CI recipients, 11 subjects exceeded the 5% preoperative CNC candidacy criterion. Both the MEETS and EXCEEDS groups improved significantly on all 5 primary study outcome measures (CI-alone CNC and AzBio, binaural SIN and sound localization, and CIQOL). The only statistically significant differences observed between the MEETS and EXCEEDS groups were that preoperative CNC and AzBio scores were significantly higher for the EXCEEDS group, as expected given that the groups were defined based on preoperative speech-perception scores in quiet. There were no statistically significant differences between the MEETS and EXCEEDS groups in postoperative scores in any test or in the magnitude of the improvement from preoperative to postoperative assessment. Conclusions: SSD- and AHL-CI recipients exceeding the 5% CNC preoperative candidacy criterion significantly improved in CI-alone speech perception, spatial hearing, and subjectively reported CIQOL outcomes and the observed benefits were indistinguishable from SSD- and AHL-CI recipients who met the 5% criterion. A less-restrictive SSD-CI and AHL-CI candidacy criterion should be considered, and larger-scale clinical trials to evaluate CI efficacy using a less-stringent candidate-ear criterion are warranted.

Investigation of mothers' elicited infant-directed speech and singing for preterm infants.

Mother's voice is a salient auditory stimulus commonly experienced during early development; after birth, characteristic acoustic modulations of mothers' infant-directed speech (IDSpeech) and singing (IDSinging) contribute to neurodevelopment. For preterm infants, early separation leads to decreased exposure to mother's voice; the impact on maternal ability to produce IDSpeech/IDSinging and infant perception of mother's voice is unknown. Fifty mother/preterm-infant dyads were enrolled in this prospective cohort study. Forty-four mothers recorded Twinkle, Twinkle Little Star in coached adult-directed speech (ADSpeech), IDSpeech, and IDSinging. Between 34.0-36.9w CGA, infants underwent high-density EEG during exposure to their mother's voice recordings. Acoustic features of mothers' voice and infant cortical response were analyzed and correlated. Acoustic features of recorded maternal ADSpeech, IDSpeech, and IDSinging were significantly different. In 33 infants with EEG, mean fundamental frequency and speech production rate (SPR) variability correlated with infant responses to ADSpeech; SPR and SPR variability correlated with IDSpeech; SPR correlated with IDSinging. Correlations were found at differing scalp locations for speech versus singing. Mothers of hospitalized preterm infants differentially modulate their voice during coached recorded language; features can then be differentiated by their preterm infants thus presenting opportunities for targeted interventions when parents cannot be present. Mothers of preterm infants can record their voice with acoustically quantifiable characteristics of infant-directed singing and speech, even when not at their infant's bedside. Recorded adult- and infant-directed speech stimuli are differentially processed in the brains of hospitalized preterm infants. The ability for mothers to create acoustically-distinct infant-directed speech in the absence of their infant may be driven by coaching to achieve an approximated sense of connection with their infant.

Effects of automatic auditory scene classification on speech perception in noise and real-world functional communication in children using cochlear implants

Objectives To investigate the effects of automatic scene classification (SCAN) on speech perception in noise and real-world functional performance in children using cochlear implants (CIs). Methods We used a within-subjects repeated measures design in two studies. The first study assessed speech perception in noise with or without SCAN enabled in 25 school-aged children. The second study evaluated functional auditory performance in real life. Parents of 18 children provided ratings using the Parents’ Evaluation of Aural/oral Performance of Children (PEACH) questionnaire; and children provided ratings using the Self Evaluation of Listening Function (SELF) questionnaire. Analyses of variance with repeated measures were used to examine the effect of SCAN. Results On average, speech perception in noise was significantly better with SCAN enabled (mean SRT: −4.1 dB; SD: 4.0), compared to SCAN disabled (mean SRT: 0.5 dB; SD: 3.5). Children’s functional performance in real life was similar between the two device settings. Conclusion Automatic auditory scene classification provides significant benefits for speech perception in noise (4.6 dB improvement). On average, there were no perceived detrimental or beneficial effects in real life. These findings support the use of SCAN in CIs for young children.

Active Models in Speech Perception: A Critical Review in Phonetics

This critical review examines four prominent active models of speech perception: quantal theory, motor theory, hyper-hypo-articulation theory, and exemplar theory. Each of these models offers distinctive insights into how listeners perceive, interpret, and categorize speech sounds. Quantal theory explores the non-linear relationship between articulation and acoustic output, emphasizing stable and unstable regions in speech production. Motor theory posits that speech perception is grounded in articulatory gestures, suggesting a direct link between production and perception. The hyper-hypo-articulation theory focuses on the speaker’s adaptive articulation, which ranges from hyper- to hypo-articulation depending on the listener's needs and the communicative context. Exemplar theory, rooted in cognitive psychology, highlights the role of memory and experience, with individual speech sounds compared to stored exemplars in memory to aid perception. Despite their contributions, none of these models offers a comprehensive solution to all speech perception challenges. Each theory is suited to specific contexts, speech features, or tasks, making it crucial for researchers to understand their limitations. Furthermore, the review underscores the importance of selecting the appropriate model for particular research or practical applications, given the variability in their functionality. Finally, it calls for future research to delve deeper into passive models of speech perception and suggests that comparative studies between active and passive models could yield valuable insights.

State-of-the-Art on the Impact of Bimodal Acoustic Stimulation on Speech Perception in Noise in Adults: A Systematic Review.

Bimodal stimulation (BS), which combines the use of a cochlear implant (CI) in one ear and a hearing aid (HA) in the opposite ear, is an established strategy to treat hearing loss by exploiting the unique capabilities of each device. CIs stimulate the auditory nerve by bypassing damaged hair cells, while HAs amplify sounds by requiring a functional hearing residual. The aim of this systematic review is to investigate the advantages and disadvantages of BS such as speech perception in noise. We examined clinical studies published from October 2020 to July 2024, following the PRISMA guidelines, focusing on the advantages and disadvantages of BS on speech perception in noise in adulthood. BS in adult patients significantly improves speech perception in quiet and noisy environments, especially for those with increased residual hearing. Unilateral CIs and BS perform similarly in quiet conditions, but BS significantly improves speech discrimination in noisy environments if loudness between the two devices is appropriately balanced. Directional microphones and programming software are new technologies that succeed in reducing environmental noise and improving verbal perception outcomes, although their features in the literature are controversial. In addition, the individuals using BS may face temporal mismatches mainly due to differing device latencies, affecting sound localization. Compensating for these mismatches can enhance localization accuracy. However, modulated noise remains a significant obstacle to verbal perception in noise. Valuable assessment tools such as music tests provide further information on hearing performance and quality of life. More research is needed to define certain selection criteria.

Increased listening effort and cochlear neural degeneration underlie behavioral deficits in speech perception in noise in normal hearing middle-aged adults.

Middle-age is a critical period of rapid changes in brain function that presents an opportunity for early diagnostics and intervention for neurodegenerative conditions later in life. Hearing loss is one such early indicator linked to many comorbidities later in life. However, current clinical tests fail to capture hearing difficulties for ∼10% of middle-aged adults seeking help at hearing clinics. Cochlear neural degeneration (CND) could play a role in these hearing deficits, but our current understanding is limited by the lack of objective diagnostics and uncertainty regarding its perceptual consequences. Here, using a cross-species approach, we measured envelope following responses (EFRs) - neural ensemble responses to sound originating from the peripheral auditory pathway - in young and middle-aged adults with normal audiometric thresholds, and compared these responses to young and middle-aged Mongolian gerbils, where CND was histologically confirmed. We observed near identical changes in EFRs across species that were associated with CND. Perceptual effects measured as behavioral readouts showed deficits in the most challenging listening conditions and were associated with CND. Additionally, pupil-indexed listening effort increased even at moderate task difficulties where behavioral outcomes were matched. Our results reveal perceptual deficits in middle-aged adults driven by CND and increases in listening effort, which may result in increased listening fatigue and conversational disengagement.

Inflammation biomarkers and neurobehavioral performance in rural adolescents.

Systemic inflammation has been associated with lower neurobehavioral performance in diverse populations, yet the evidence in adolescents remains lacking. Cytokines can alter neural network activity to induce neurocognitive changes. This work seeks to investigate the association between inflammation and neurobehavior in adolescents living in a rural region of Ecuador. We examined 535 adolescents in rural communities of Ecuador (ESPINA study), 508 of which had neurobehavioral assessments (NEPSY-II) and circulating plasma levels of inflammatory markers (CRP, IL-6, TNF-⍺, sICAM-1, sVCAM-1, SAA, and sCD14). Associations between inflammatory biomarker concentrations and neurobehavioral scores were examined using adjusted bivariate semi-parametric models with generalized estimating equations. A partial least square regression approach was used to create composite variables from multiple inflammation biomarkers and model their association with cognitive outcomes. Higher sCD14 and TNF-α concentrations were significantly associated with lower social perception scores, by -0.47 units (95% CI: -0.80, -0.13) and -0.42 (-0.72, -0.12) for every 50% increase in inflammatory marker concentration, respectively. Similarly, every 50% increase in the inflammation summary score was associated with a significantly lower Social Perception score by -0.11 units (-0.19, -0.03). A unit increase in inflammatory composites of seven markers were associated with lower scores in language (-0.11 units, p=0.04), visuospatial processing (-0.15, p= 0.09), and social perception (-0.22, p=0.005) domains. Higher levels of inflammation were associated with lower neurobehavioral performance in adolescents, especially with social perception. In addition, using a robust analytic method to examine an association between a composite inflammatory variable integrating seven markers led to additional findings, including the domains of language and visuospatial processing. A longitudinal follow-up of such investigations could unveil potential changes in inflammation-neurobehavior performance links through developmental stages and intervention opportunities.

Investigating the Effect of Blurring and Focusing Current in Cochlear Implant Users with the Panoramic ECAP Method.

For some cochlear implants (CIs), it is possible to focus electrical stimulation by partially returning current from the active electrode to nearby, intra-cochlear electrodes (partial tripolar (pTP) stimulation). Another method achieves the opposite: "blurring" by stimulating multiple electrodes simultaneously. The Panoramic ECAP (PECAP) method provides a platform to investigate their effects in detail by measuring electrically evoked compound action potentials and estimating current spread and neural responsiveness along the length of the CI electrode array. We investigate how sharpening and broadening the electrical current spread are reflected in PECAP estimates. PECAP measurements were recorded at most comfortable level in 12 ears of Advanced Bionics CI users. Focused thresholds were also determined. For the electrodes with the highest and lowest focused thresholds, additional PECAP measurements were recorded while stimulating in pTP mode and in "blurred" mode with 3 or 5 adjacent electrodes simultaneously stimulated. Current spread and neural responsiveness were then estimated along the electrode array using PECAP. PECAP revealed increased current spread estimates across participants for blurred stimulation of the targeted electrodes towards the apex of the cochlea. Variable results for pTP stimulation were found, with two of eight ears appearing to drive a small group-level effect of increased current spread. When stimulating multiple electrodes simultaneously, PECAP detected localized increases in current spread towards the apex (but not the base) of the cochlea. pTP stimulation showed mixed effects on PECAP current spread estimates. These findings are in line with behavioral speech perception studies and have implications for cochlear implant optimization.

Computational Architecture of Speech Comprehension in the Human Brain

Understanding the computational algorithm that gives rise to human language is a shared endeavor among neuroscience, linguistics, and machine learning. We propose a conceptual framework for making measurable progress toward this goal by studying the subcomponents of the processing system: its underlying representations, operations, and information flow. We review evidence from neurophysiology, neuropsychology, linguistic theory, and computational modeling and suggest future directions to push the field forward in developing a precise characterization of spoken language understanding. Overall, we claim that representations of speech properties, and the operations that generate and manipulate those representations, exist within a highly parallel, highly redundant spatiotemporal regime.

Contrastive learning of shared spatiotemporal EEG representations across individuals for naturalistic neuroscience

Neural representations induced by naturalistic stimuli offer insights into how humans respond to stimuli in daily life. Understanding neural mechanisms underlying naturalistic stimuli processing hinges on the precise identification and extraction of the shared neural patterns that are consistently present across individuals. Targeting the Electroencephalogram (EEG) technique, known for its rich spatial and temporal information, this study presents a framework for Contrastive Learning of Shared SpatioTemporal EEG Representations across individuals (CL-SSTER). CL-SSTER utilizes contrastive learning to maximize the similarity of EEG representations across individuals for identical stimuli, contrasting with those for varied stimuli. The network employs spatial and temporal convolutions to simultaneously learn the spatial and temporal patterns inherent in EEG. The versatility of CL-SSTER was demonstrated on three EEG datasets, including a synthetic dataset, a natural speech comprehension EEG dataset, and an emotional video watching EEG dataset. CL-SSTER attained the highest inter-subject correlation (ISC) values compared to the state-of-the-art ISC methods. The latent representations generated by CL-SSTER exhibited reliable spatiotemporal EEG patterns, which can be explained by properties of the naturalistic stimuli. CL-SSTER serves as an interpretable and scalable framework for the identification of inter-subject shared neural representations in naturalistic neuroscience.

Auditory and vestibular function in mitochondrial patients harbouring the m.3243A>G variant.

Hearing impairment is a frequent clinical feature in patients with mitochondrial disease harbouring the pathogenic variant, m.3243A>G. However, auditory neural dysfunction, its perceptual consequences and implications for patient management are not established. Similarly, the association with vestibular impairment has not yet been explored. This case-control study investigated in 12 adults with genetically confirmed m.3243A>G adults [9 females; 45.5 ± 16.3 years (range 18-66); 47.1 ± 21.5 hearing level, dB] compared with 12 age, sex and hearing level-matched controls with sensory (cochlear level) hearing loss [9 females; 46.6 ± 11.8 years (range 23-59); 47.7 ± 25.4 hearing level, dB]. Participants underwent a battery of electroacoustic, electrophysiologic and perceptual tests, which included pure tone audiometry, otoacoustic emissions, auditory brainstem responses, auditory temporal processing measures, monaural/binaural speech perception, balance and vestibular testing and self-reported questionnaires (dizziness and hearing disability). Our findings showed evidence of auditory neural abnormality and perceptual deficits greater than expected for cochlear pathology. Compared with matched controls with sensory hearing loss, adults with mitochondrial disease harbouring m.3243A>G had abnormal electrophysiologic responses from the VIII nerve and auditory brainstem (P = 0.005), an impaired capacity to encode rapidly occurring acoustic signal changes (P = 0.005), a reduced ability to localize sound sources (P = 0.028) and impaired speech perception in background noise (P = 0.008). Additionally, vestibular dysfunction (P = 0.011), greater perceived dizziness (P = 0.001) and reduced stance time (balance, P = 0.009) were also seen in participants with m.3243A>G mitochondrial disease when compared with matched counterparts. This pilot study revealed that auditory evaluation including evoked potential responses from the auditory nerve/brainstem and speech perception in noise tests should form an important part of the management for individuals with m.3243A>G-related mitochondrial disease. Those presenting with hearing impairment and symptoms concerning balance and dizziness should undergo vestibular testing and appropriate management.

Contrastive adaptation effects along a voice-nonvoice continuum.

Adaptation to the environment is a universal property of perception across all sensory modalities. It can enhance the salience of new events in an ongoing background and helps maintain perceptual constancy in the face of variable sensory input. Several contrastive adaptation effects have been identified using sounds within the categories of human voice and musical instruments. The present study investigated whether such contrast effects can occur between voice and nonvoice stimulus categories. A 10-step continuum between "voice" (/a/, /o/, or /u/ vowels) and "instrument" (bassoon, horn, or viola) sounds was generated for each of the nine possible pairs. In each trial, an adaptor, either a voice or instrument, was played four times and was followed by a target from along the appropriate continuum. When trials with voice and instrumental adaptors were grouped into separate blocks, strong contrastive adaptation effects were observed, with the target more likely to be identified as a voice following instrumental adaptors and vice versa (Experiment 1). The effects were not observed for visual image adaptors (Experiment 2). The effects were somewhat larger when the adaptors and the target were presented to the same than to different ears, but significant adaptation was observed in both conditions, suggesting contributions of central mechanisms, following binaural integration (Experiment 3). The effect accumulated when the same type of adaptor was presented consecutively and persisted following the end of the adaptors (Experiment 4). The discovery of voice-nonvoice contrastive pairs opens the possibility of studying perceptual or neuronal voice selectivity while keeping acoustic features constant. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The Effect of Root-Mean-Square and Loudness-Based Calibration Approach on the Acceptable Noise Level

environment contains many background noises in everyday conversations, it is necessary to evaluate the noise tolerance. The Acceptable Noise Level (ANL) provides an approach to quantifying the maximum amount of background noise a listener is willing to put up with while listening to a target story without becoming tense. Exploring noise tolerance in speech perception, the study investigates how different calibration methods impact normal hearing participants’ monotic and dichotic ANL results. Methods: This investigation utilizes a pared-sample t-test for statistical analysis, adopting a comparative observational approach. This study applied the Persian version of the typical ANL test. Two approaches have equalized the target and background stimuli: Root Mean Squared (RMS) and loudness match calibration via Adobe Audition. Using these modified materials the Most Comfortable Level (MCL), the Background Noise Level (BNL), and ANL were compared in terms of RMS and loudness match calibration. Fifty normal persons aged (18–39), under the conditions of monotic and dichotic listening, participated in this study. Results: The statistical analysis using a paired-sample t-test revealed no significant differences in the outcomes of the ANL test between the calibrations of RMS and loudness matching under both monotic and dichotic listening conditions (p=0.31 and p=0.67, respectively). Conclusion: The study suggests that calibration procedures, namely RMS and Loudness matching, do not affect ANL in either monotic or dichotic conditions. Keywords: Loudness; calibration; acceptable noise level; root mean square

A Non-Surgical Wearable Option for Bone Conduction Hearing Implants: A Comparative Study with Conventional Bone Conduction Hearing Aids Mounted on Eyeglasses.

This study aimed to compare the audiological benefits of a non-implantable wearable option for a bone conduction (BC) implant mounted on an arch (SoundArc) to those of traditional BC hearing aids (HAs) mounted on eyeglasses (BCHAs) in patients with moderate to severe conductive or mixed hearing loss. A preliminary cross-sectional observational prospective cohort study was conducted in the Tertiary Audiological Department, University Hospital. Fourteen adults with conductive or mixed hearing loss (PTA at 0.5-1-2-4 KHz = 67 ± 15 dB HL) who had been wearing conventional BCHAs mounted on eyeglasses for at least 3 years and had declined surgical implantation of a bone conduction hearing implant (BCHI) were included in the study. Unaided and aided pure-tone air conduction (AC) and bone conduction (BC) thresholds, as well as speech tests in quiet and noise, were recorded at baseline and in two different settings: with a BCHI mounted on SoundArc® and with their own BCHAs mounted on eyeglasses using two couplers. Participants completed questionnaires in both conditions, including the International Inventory for Hearing Aids (IOI-HA), the Hearing Handicap Inventory for Adults/Elderly (HHIA/E), the Speech, Spatial, and Qualities of Hearing Scale (SSQ), a 10-point visual analog scale (VAS), and the Fatigue Impact Scale (FIS). A significant functional gain was observed in both settings (p = 0.0001). Better speech perception in quiet and noise was observed with SoundArc compared to conventional BCHAs on eyeglasses (improvements in word repetition scores in noise: +19.3 at SNR +10 dB, p = 0.002; +12.1 at SNR 0 dB, p = 0.006; and +11.4 at SNR -10 dB, p = 0.002). No significant differences were found in IOI-HA, FIS, and HHIA/E scores. However, significantly better SSQ scores were reported for SoundArc in all domains (p = 0.0038). Although patients were accustomed to using BCHAs mounted on eyeglasses, the bone conduction wearable option of the BCHI (SoundArc) proved to be a viable alternative for adult patients with conductive or mixed hearing loss who are unable or unwilling to undergo BCHI surgery.