Infants gradually attune to the consonants of their native language throughout the first year of life. This study investigated the role of auditory temporal processing in this early perceptual attunement. We used electrophysiological measures to investigate the processing of temporal modulations, the amplitude modulation (AM) and frequency modulation (FM) in speech. Cortical auditory evoked potentials (CAEPs) were measured for native (voiced /b/ and unvoiced unaspirated /p/) and nonnative (unvoiced aspirated English /p/) consonants in French-learning 6-month-old and 10-month-old infants. We also included a group of young adult listeners to serve as a reference group for qualitative comparisons with infants, as there were no prior studies on the effects of temporal degradation on adults' CAEPs. The three consonants were presented under three conditions where AM and FM were differentially degraded or preserved: (a) original FM and AM preserved (no stimulus degradation), (b) fast AM (degrading FM and preserving the original AM), and (c) slow AM only (degrading FM and faster AM fluctuations). Temporal degradation affected CAEPs differently across infant age groups, suggesting ongoing development of auditory processing mechanisms for FM and AM cues. Six-month-olds exhibited heightened sensitivity to the reduction of fast AM cues, whereas 10-month-olds were more sensitive to FM degradation. Age significantly shapes cortical auditory responses to speech temporal cues. Six-month-olds' neural responses were primarily influenced by fast AM reduction (> 8 Hz), whereas 10-month-olds' responses were more susceptible to FM degradation. Adults did not show either pattern, indicating that the perceptual weighting of temporal modulations in speech continues to develop beyond infancy. https://doi.org/10.23641/asha.32030250.

Considerable variability in auditory and speech outcomes among pediatric cochlear implant (CI) recipients has raised ongoing debate regarding whether early auditory perception directly determines later speech intelligibility, particularly in tonal language environments where pitch cues are critical for communication. This longitudinal study evaluated 64 prelingually deaf children aged 1-5 years over 12 months following unilateral implantation, integrating four standardized behavioral scales-the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS), Categories of Auditory Performance (CAP), Monosyllabic-Trochee-Polysyllabic Word Test (MESP), and Speech Intelligibility Rating (SIR)-together with cortical auditory evoked potentials (CAEP). All measures demonstrated significant time-dependent improvement (p < 0.001): IT-MAIS and CAP increased rapidly within 3 months post-activation, followed by progressive gains in MESP and SIR reflecting enhanced speech perception and intelligibility. Multiple regression analysis showed that CAP at 3 months was significantly associated with SIR outcomes at 12 months (β = 0.201, p = 0.010), explaining 26.6% of the variance, supporting a hierarchical relationship between early auditory comprehension and later expressive language development. Furthermore, P1 latency shortening on CAEP correlated with higher SIR scores (r = 0.275, p = 0.028), supporting cortical plasticity as a neural mechanism underlying behavioral recovery. No significant between-group differences were observed for most auditory and speech perception measures. However, SIR scores at 12 months were modestly higher in children with normal cochlear anatomy. Overall developmental trajectories remained comparable between groups, suggesting that functional auditory experience plays a major role in rehabilitation outcomes. These findings provide longitudinal behavioral and electrophysiological evidence suggesting that early auditory integration is associated with later speech production outcomes. The proposed multimodal framework offers a reproducible, evidence-based approach for monitoring auditory-speech trajectories and guiding individualized rehabilitation in pediatric CI users.

Decoding selective attention in cochlear implant users with ipsilateral residual hearing.

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological syndrome resulting from increased cerebrospinal fluid volume without significant increase in intracranial pressure. The diagnosis is difficult and investigating other tools that can assist in this process is essential. Auditory Evoked Potentials (AEPs) can be used to assess the auditory pathway integrity and monitor cognitive auditory functions. The objective of this study was to investigate the applicability of the AEPs as a potential monitoring tool for detecting clinical improvements associated with cerebrospinal fluid removal by lumbar puncture and VPS placement in patients with iNPH. This longitudinal study, evaluated 17 individuals with iNPH, aged over 60years who underwent the ventriculoperitoneal shunt, by Auditory Brainstem Response (ABR) and Cortical Auditory Evoked Potentials (CAEP) at three different times: before the lumbar puncture during the Tap test, two to four hours after the lumbar puncture, and after the ventriculoperitoneal shunt. A decrease in P3 latency was observed after lumbar puncture during Tap test. No statistically significant differences were observed between assessments for P1, N1 P2, N2 latencies or P1-N1, P2-N2 and N2-P3 amplitudes of the CAEP, as well as for the absolute and interpeaks latencies of the ABR. After the removal of significant volumes of cerebrospinal fluid in patients with iNPH, lower P3 latency values were found, suggesting an increase in the speed of acoustic information processing, during the Tap test. This result brings an insight on the applicability of this procedure as an auxiliary method for monitoring clinical improvements associated with cerebrospinal fluid removal in iNPH.

Effect of noise on T-complex responses: an evoked-related potential study.

Objectives: This study aimed to evaluate auditory cortical maturation in pediatric cochlear implant (CI) users using speech-evoked cortical auditory evoked potentials (CAEPs) and to compare P1 latency responses with age-matched normal-hearing (NH) peers. Secondary objectives included examining the relationship between P1 latency, age, and duration of implant use to assess experience-dependent cortical plasticity. Materials and Methods: Seventy children were enrolled, including 40 prelingually deaf CI users and 30 NH controls matched for age and sex. CAEPs were recorded using the HEARLab system with three speech tokens representing low (/m/), mid (/g/), and high (/t/) frequencies, presented at 55 dB SPL in a free-field setup. The P1 component was identified as the first positive deflection between 50 and 150 ms after stimulus onset. Group comparisons were performed using Student's t-test, and correlations between P1 latency, age, and implant-use duration were analyzed using the Pearson correlation test (p < 0.05). Results: Mean P1 latencies were significantly longer in CI users than in NH peers for the /m/ and /t/ stimuli (p = 0.036 and p = 0.045, respectively), while no significant difference was found for /g/ (p = 0.542). In NH children, P1 latency negatively correlated with age (r = -0.44, p < 0.05), indicating maturation-related shortening. Among CI users, longer implant-use duration was associated with shorter P1 latencies across all speech tokens (/m/: r = -0.37; /g/: r = -0.49; /t/: r = -0.43; p < 0.05 for all). Conclusions: Speech-evoked CAEPs provide a sensitive and objective measure of auditory cortical development in children with cochlear implants. P1 latency reflects both chronological and hearing-age-related maturation, supporting its clinical use as a biomarker for cortical plasticity and rehabilitation progress in pediatric CI care.

Cortical processing of speech sounds in individuals with cochlear hearing loss and auditory neuropathy.

Background/Objectives: Speech processing engages both hemispheres of the brain but exhibits a degree of hemispheric asymmetry. This asymmetry, however, is not fixed and can be shaped by stimulus-related and listener-related factors. The present study examined how background noise and attention influence hemispheric differences in speech processing using high-density cortical auditory evoked potentials (CAEPs). Methods: Twenty-five young adults with clinically normal hearing listened to meaningful bisyllabic Kannada words under two background conditions (quiet, speech-shaped noise) and two attentional conditions (active, passive). N1 peak amplitudes were compared between the left and right hemispheres across conditions using linear mixed-effects modeling. Results: Results revealed significantly larger N1 amplitudes in the left hemisphere and during active compared to passive listening, confirming left-hemisphere dominance for speech processing and robust attentional modulation. In contrast, background noise did not significantly modulate N1 amplitude or hemispheric asymmetry. Importantly, a significant Hemisphere × Attention interaction indicated that hemispheric asymmetry depended on attentional state, with clear left-hemisphere dominance being observed during active listening in both quiet and noise conditions, whereas hemispheric differences were reduced or absent during passive listening, irrespective of background. Conclusions: Together, these findings demonstrate that attentional engagement, rather than background noise, plays a critical role in modulating hemispheric specialization during early cortical speech processing, highlighting the adaptive nature of auditory cortical mechanisms in challenging listening environments.

Objective evaluation of hearing aids fitting efficacy in pediatric populations using cortical auditory evoked potentials.

The central auditory system and its maturational aspects have been a topic of interest on the raise in recent times. Cortical auditory evoked potentials (CAEP) might be a promising electrophysiological tool, applicable both in the diagnosis of central auditory processing disorders and other conditions, as well as in clinical evaluation of amplification and cochlear implantation effectiveness in children. Of this study was to perform a scoping review on CAEP as biomarkers of cortical maturation in children and infants with normal and impaired hearing. A keyword search was performed across the PubMed, Scopus, Web of Science, and Elibrary.ru databases. 86 sources were included in the review according to the criteria. In children with normal hearing, the latency of CAEP components decreases with age. An increase in latency and a change in the morphology of CAEP are observed in cases of hearing impairment, prematurity, speech, and certain neurological disorders. CAEP might serve as a reliable biomarker for assessing the maturation of the central auditory system in both children with normal hearing and those with hearing impairment.

Background: Speech perception requires a balanced interplay between the bottom-up sensory and top-down cognitive processes. The differential impact of aging on the bottom-up and top-down processes in the auditory system has been debated.&lt;br&gt; Purpose: The primary aim of this study was to use auditory event-related potentials (ERPs) including the cortical auditory evoked potential (CAEP), mismatch negativity (MMN), and the P300 in young and upper-middle-aged adults to determine early effects of aging on auditory processing at the preattentive and attentive levels. The secondary aim of this study was to determine the correlations between ERPs and subjective evaluation of hearing as well as cognitive function.Research Design: ERPs were recorded in response to an oddball stimulus paradigm under passiveand attentive listening conditions, respectively. The frequency discrimination (FD) test, the five-itemSpeech Spatial and Qualities of Hearing Scale (SSQ) questionnaire, and computerized cognitive testswere also administered.&lt;br&gt; Study Sample: A total of 20 young adults (Young group aged 20–30 years; mean ¼ 23.01 6 1.43 years) and 10 upper-middle-age adults (Upper-middle-age group aged 50–60 years; mean ¼ 53.67 6 2.83 years) without hearing impairment participated in the study. They were recruited in the Greater Cincinnati area through advertisements for this study.&lt;br&gt; Data Collection and Analysis: The amplitude and latency of ERP peaks (N1 and P2 of the CAEP, MMN, and P300), the FD threshold, reaction time of cognitive tests, and SSQ scores were collected from each participant. Statistical analyses were performed to investigate the effects of aging on all these outcomes and the correlations between ERPs and other measures.&lt;br&gt; Results: Compared to the Young group, the Upper-middle-aged group showed a larger amplitude and shorter latency in the CAEP peak components and a smaller amplitude and longer latency in the MMN and P300 peaks. Despite the fact that the Upper-Middle-aged group had poorer averaged hearing thresholds, different ERP measures, and poorer cognitive performance, their FD threshold did not differ from that of the Young group.&lt;br&gt;Conclusions: Early signs of aging in the auditory system can be shown in preattentive and attentive ERPs. &lt;br&gt; Clinical Relevance Statement: ERPs provide objective measures of early signs of age-related changes in auditory function.

Speech perception in noise (SPiN) is a critical challenge for individuals with sensorineural hearing loss (SNHL), and current behavioral assessments can be unreliable in populations with language barriers or cognitive impairment. Cortical auditory evoked potentials (CAEPs) can serve as a supplementary measurement as they often show strong correlations with SPiN outcomes across diverse hearing profiles. Following PRISMA and SWiM guidelines, this systematic review includes studies from PubMed, Web of Science, and Scopus databases that examined the relationship between non-task related CAEPs and SPiN outcomes in adults with normal hearing, SNHL, or cochlear implants. Sixteen studies were included, encompassing 238 participants with SNHL and 204 participants with normal hearing. Across studies, N1 latency, P2 latency, and N1-P2 amplitude of the onset CAEP and acoustic change complex (ACC) are most consistently correlated with SPiN performance, particularly in sentence-based tests. The mismatch negativity (MMN) showed limited predictive value, as findings varied by age and hearing status. A meta-analysis was not conducted due to methodological heterogeneity. Onset CAEP and ACC N1 and P2 latencies together with N1-P2 amplitudes particularly demonstrate potential as electrophysiological indicators of SPiN performance. Their clinical utility is promising for populations where behavioral testing can be unreliable, such as CI users or individuals with cognitive or language barriers. However, standardization of protocols and further longitudinal research are needed to validate their application in clinical settings. https://www.crd.york.ac.uk/PROSPERO/view/CRD42023404158, identifier PROSPERO (CRD42023404158).

To evaluate and monitor, through electrophysiological assessment of hearing, the integrity of the peripheral and central auditory pathways in infants with Peri-intraventricular hemorrhage and/or Periventricular Leukomalacia (PIVH/PVL) who stayed in a Neonatal Intensive Care Unit (NICU), aiming to verify the occurrence of possible neural dysfunctions in this system. This prospective longitudinal study evaluated preterm Newborns (NBs) and infants at the time of hospital discharge and after 3- and 6-months. The Study Group (SG) had 12 females and 11 males, with gestational age between 25- and 33-weeks, and a mean gestational age of 29.82-weeks at birth. The Control Group (CG) had 26 healthy NBs, distributed in 13 females and 13 males, with gestational age between 27- and 33-weeks and a mean of 30.67-weeks of gestational age at birth. All participants underwent Auditory Brainstem Response (ABR) and Cortical Auditory Evoked Potentials (CAEP) P1, N1, P2, at the time of hospital discharge, and 3- and 6-months after discharge. Each group's results were compared using statistical tests. Evolutionary study of mean ABR and CAEP latencies in infants in the study and control group showed a similar pattern over the six months after hospital discharge. The comparison of brainstem and cortical potentials showed that auditory function is symmetrical in the peripheral and central portions of the auditory pathway in both groups. The maturation of the ABR and CAEP waves in both groups developed in a very similar way over the six months after hospital discharge.

Abstract Background Misophonia, also known as selective sound sensitivity syndrome, is a persistent condition characterized by adverse emotional reactions and autonomic arousal triggered by particular sounds. The purpose of this study is to investigate the auditory pathway processing in persons with misophonia using click auditory brainstem response (ABR) and cortical auditory evoked potentials (CAEPs). This study included 20 healthy controls and 20 patients with misophonia diagnosed according to the misophonia diagnostic criteria of Schroder et al. (2013). All subjects were subjected to a full audiological evaluation including pure tone audiometry (PTA) with detection of uncomfortable loudness level (UCLL) and most comfortable loudness level (MCLL), immitancemetry, cortical auditory evoked potentials (CAEPs) and auditory brainstem response (ABR). Results Both UCLL and MCLL were higher in patients with misophonia than the healthy controls and CAEPs results had earlier P1 and N1 waves and larger P1 and P2 amplitudes in frequencies 500, 1000, 2000, and 4000 Hz in the misophonia group. Conclusion Misophonia patients have significant findings in CAEPs waves’ amplitudes and latencies together with MCLL and UCLL.

ABSTRACT Age-related declines in speech recognition are consistently linked to several interrelated factors – auditory acuity (peripheral and/or central), cognition, linguistic processing, neurophysiological efficiency, etc. These declines become more apparent in adverse listening conditions, such as informational masking, the additional masking effects that occur due to linguistic and/or cognitive confusions between the target sound and masker. In this study, we evaluated the age-related changes in the cortical representation of speech under different masking (informational vs energetic) and attention (active vs passive) conditions. We measured high-density cortical auditory evoked potentials (CAEPs) in 60 participants (30 young adults and 30 older adults) with clinically normal hearing (pure tone average <15 dB HL). CAEPs were recorded in the presence of informational and energetic (no linguistic information) maskers, while the participants either attended (active attention) or ignored (passive attention) the stimuli. Results showed that informational maskers caused significantly greater N1 latency delays than energetic maskers, with older adults showing significantly greater delays than younger adults. Active attention resulted in significantly larger N1 amplitudes compared to passive attention, with minimal age-related differences, possibly due to the strict criteria of auditory acuity in the older adult group. Further, microstate segmentation analyses, in addition to confirming the age-related delays in cortical responses (similar to N1 latencies), revealed longer engagement of fronto-central cortical regions under informational maskers, regardless of the presence of lexical-semantic information in the maskers. These findings, therefore, highlight the systematic effects of aging, attention, and linguistic complexity on the cortical representation of masked speech.

Hearing performance among cochlear implant (CI) users is associated with the degree of experience with using the device, but different measures of experience are available. Here, we compared 3 different measures of experience: the duration of time elapsed since activation (CI duration), the hours of device use per day (median datalogging hours), and the total cumulative device use (TDU). A retrospective analysis of 119 adult CI users (53 female) who underwent postoperative electrophysiological testing for cortical auditory evoked potentials (CAEPs). CI experience was compared between users with present and absent CAEP responses. We also examined associations between CAEP latencies and amplitudes and the degree of CI experience. For a subset of users, postoperative speech perception test scores were available, and associations with CI experience were also investigated. Significant associations were found between the presence of CAEP responses and both median datalogging hours and TDU, but not CI duration. No significant correlations were observed between CI experience and the amplitudes or latencies of CAEP waveform components. A significant correlation was observed between both median datalogging hours and TDU with speech perception in quiet test scores. These findings suggest that with respect to central auditory processing and hearing outcomes, median datalogging hours and TDU are superior measures of the degree of experience compared with CI duration.

Auditory evoked potentials (AEPs), including the auditory brainstem response (ABR) and cortical auditory evoked potential (CAEP), are widely used to estimate hearing thresholds in individuals unable to provide behavioral responses. However, it remains unclear whether brainstem or cortical activity better reflects perceptual thresholds, and how stimulus characteristics influence this relationship. This study investigated the agreement between evoked potentials and behavioral thresholds using different stimuli and presentation rates. Two experiments examined agreement between AEPs and behavioral thresholds. Experiment 1 (n = 8 ears) used LS CE-Chirp stimuli at 33.3 stimuli/second. Experiment 2 (n = 12 ears) used 1 kHz tone burst stimuli and examined three conditions: behavioral thresholds at 33.3 stimuli/second (Experiment 2a), behavioral thresholds at 1.0 stimuli/second (Experiment 2b), and standard 1 kHz pure tone audiometry (Experiment 2c). Different adult groups (≥18 years) were recruited for each experiment. Behavioral thresholds were obtained via the Hughson-Westlake method. Thresholds were compared using Wilcoxon signed-rank tests. Agreement patterns varied systematically with stimulus characteristics. For LS CE-Chirp stimuli at 33.3 stimuli/second, ABR thresholds showed significantly better agreement with behavioral thresholds than CAEP thresholds (p < 0.05). For 1 kHz tone burst stimuli at 33.3 stimuli/second, no significant difference was observed between ABR and CAEP agreement with behavioral thresholds (p > 0.05). However, at 1.0 stimuli/second, CAEP thresholds demonstrated significantly better agreement with behavioral thresholds than ABR thresholds (p < 0.05). Both ABR and CAEP thresholds showed comparable agreement with clinical 1 kHz pure tone audiometry thresholds (p > 0.05). These preliminary findings demonstrate that both stimulus type and presentation rate influence threshold estimation, with slower rates favoring cortical-behavioral agreement and faster rates favoring brainstem-behavioral agreement. These context-dependent patterns may guide measurement strategies and support their use in the identification of auditory dysfunction. Further research with larger samples is needed to validate these findings and establish their clinical applicability.

ABSTRACTObjectiveTo test the hypothesis that auditory central inhibition is reduced in tinnitus patients and explore whether improving this inhibitory function could alleviate tinnitus severity.MethodsWe recruited 16 chronic tinnitus patients and 14 age‐matched healthy controls, all of whom exhibited clinically normal audiometric thresholds. Electroacoustic measures, cortical auditory evoked potentials (CAEP), were used to assess neural activity. Contralateral noise stimulation was employed to evaluate contralateral suppression (CS) of CAEP amplitude.ResultsSignificant differences in CS of N100 and P300 amplitude were observed between tinnitus patients and healthy controls, indicating impaired central inhibition in tinnitus. After 3 months of tinnitus masking therapy, patients showed significant improvements in CS of N100 and P300 amplitudes, which correlated with a reduction in tinnitus handicap inventory scores. Receiver operating characteristic curve analysis confirmed that changes in CS, especially in the P300 amplitude, reliably reflect treatment efficacy.ConclusionsThis study highlights the critical role of central auditory inhibition in tinnitus pathophysiology and suggests that neurophysiological markers, particularly changes in CS of P300 amplitude, could serve as reliable biomarkers for evaluating treatment outcomes.SignificanceThese findings pave the way for developing targeted therapies aimed at restoring central auditory inhibition, offering more effective and personalized treatment strategies for tinnitus patients.

This study investigated the applicability of speech-induced binaural beats (SBBs), a phase modulation procedure that can be applied to arbitrary speech signals to generate cortical auditory evoked potentials (CAEPs) as an objective marker of binaural interaction when presented dichotically, in a free-field environment. Furthermore, the effect of speech-shaped masking noise on CAEPs was investigated. Nineteen normal-hearing participants listened to sentences from a sentence matrix test. Sentences were presented from two loudspeakers situated 1 m away to the left and right of the participant. Each sentence contained one SBB and was presented in silence and in three different variations of masking noise: (a) identical noise from the same loudspeakers as the speech signals, (b) modified/phase-modulated noise from the same loudspeakers as the speech signals, and (c) noise presented from a separate loudspeaker placed behind the participants. Additionally, five participants listened to the sentences without noise, with and without one ear occluded, to ascertain the possibility of acoustic interference. CAEPs were successfully recorded in all participants, in the no noise condition and all noise conditions. The presentation of noise from a separate loudspeaker significantly reduced the N1 amplitude. No CAEPs were recorded when one ear was occluded, indicating no contribution of acoustic interference. SBBs can be used to reliably evoke CAEPs as an objective marker of binaural interaction in the free field with masking noise. The advantage of this method is the use of speech material and the possible integration with existing behavioral tests for binaural interaction that utilize speech signals. https://doi.org/10.23641/asha.30063004.

Purpose: This study aimed to assess the effectiveness of the cortical auditory evoked potential (CAEP) test for estimating hearing thresholds with a clinical auditory evoked potential (AEP) system. Method: Thirty individuals whose hearing thresholds were not ≥ 25 dB HL (aged 20–53 years) and 20 individuals who are hard of hearing (aged 22–80 years) participated in this study. Behavioral hearing thresholds were obtained from participants in both groups. CAEPs for 500-, 1000-, 2000-, and 4000-Hz tone bursts were recorded using a two-channel clinical AEP system. Results: The mean CAEP and behavioral threshold difference for participants whose hearing thresholds are within 25 dB HL was ≤ 15 dB, and for individuals who are hard of hearing, it was ≤ 10 dB. There was no significant effect of test frequency in CAEP and behavioral threshold differences. Similar findings have been reported in the literature. Conclusions: The CAEP thresholds closely match behavioral thresholds in adults with and without hearing loss. The findings of our study suggest that using a clinical AEP system may allow for the estimation of hearing thresholds using the CAEP test in adults.