OBJECTIVE: Tinnitus is a condition that causes people to hear sounds without an external source. One significant issue arising from this condition is the difficulty in communicating, especially in the presence of noisy backgrounds. The process of understanding speech in challenging situations requires both cognitive and auditory abilities. Since tinnitus presents unique challenges, it is important to investigate how it affects speech perception in noise.
METHODS: In this review, 32 articles were investigated to determine the effect of tinnitus on the effect of speech in noise perception performance. Based on the meta-analysis performed using a random-effects model, meta-regression was used to explore the moderating effects of age and hearing acuity.
RESULTS: A total of 32 studies were reviewed, and the results of the meta-analysis revealed that tinnitus significantly impacts speech in terms of noise perception performance. Additionally, the regression analysis revealed that age and hearing acuity are not significant predictors of speech in noise perception.
CONCLUSIONS: Our findings suggest that tinnitus affects speech perception in noisy environments due to cognitive impairments and central auditory processing deficits. Hearing loss and aging also contribute to reduced speech in noise performance. Interventions and further research are necessary to address individual challenges associated with continuous subjective tinnitus.

UNASSIGNED: Difficulty understanding speech following concussion is likely caused by auditory processing impairments. We hypothesized that concussion disrupts pitch and phonetic processing of a sound, cues in understanding a talker.
UNASSIGNED: We obtained frequency following responses to a syllable from 120 concussed and 120 control. Encoding of the fundamental frequency (F0), a pitch cue and the first formant (F1), a phonetic cue, was poorer in concussed children. The F0 reduction was greater in the children assessed within 2 weeks of their injuries.
UNASSIGNED: Concussions affect auditory processing. Results strengthen evidence of reduced F0 encoding in children with concussion and call for longitudinal study aimed at monitoring the recovery course with respect to the auditory system.

BACKGROUND: Identification of auditory processing disorders is achieved using questionnaires along with linguistic, non-linguistic, and auditory processing tests. Notably, the questionnaires \"Children\'s Auditory Performance Scale\" (CHAPS) and \"Auditory Processing Domain Questionnaire\" (APDQ) are widely recognized and used. The current study investigated the psychometric properties of the CHAPS and APDQ in Greek Cypriot children.
METHODS: The CHAPS and APDQ questionnaires were completed by parents of 40 Greek Cypriot children, 16 typically developing (TD) children, and 24 children with a history of Speech Sound Disorders (SSDs).
RESULTS: There were significant differences between the two groups on both questionnaires. Cronbach\'s alpha was calculated at α = 0.922 for the CHAPS total score and α = 0.926 for the APDQ total score. The Receiver Operating Curve (ROC) analysis provided a cut-off point equal to -0.30 (AUC 0.849, p < 0.001) for CHAPS and a cut-off point equal to 90.00 (AUC 0.820, p < 0.001) for APDQ. Significant positive Spearman ρ correlations were observed between the CHAPS and APDQ (ρ = 0.639, p = 0.001).
CONCLUSIONS: The CHAPS and APDQ can identify distinct auditory processing characteristics between in children with SSDs and TD children.

UNASSIGNED: Research indicates that people with Parkinson\'s disease (PwPs) may experience challenges in both peripheral and central auditory processing, although findings are inconsistent across studies. Due to the diversity of auditory measures used, there is a need for standardized, replicable hearing assessments to clarify which aspects of audition are impacted in PWPs and whether they are linked to motor and non-motor symptoms.
UNASSIGNED: To characterize auditory processes and their possible alteration in PwPs. To address this, we collected a comprehensive set of standardized measures of audition using PART, a digital testing platform designed to facilitate replication. Additionally, we examined the relationship between auditory, cognitive, and clinical variables in PwPs.
UNASSIGNED: We included 44 PwPs and 54 age and education matched healthy controls. Assessments included detection of diotic and dichotic frequency modulation, temporal gaps, spectro-temporal broad-band modulation, and speech-on-speech masking.
UNASSIGNED: We found no statistically significant differences in auditory processing measures between PwPs and the comparison group (ps > 0.07). In PwPs, an auditory processing composite score showed significant medium size correlations with cognitive measures (0.39 < r<0.41, ps < 0.02) and clinical variables of motor symptom severity, quality of life, depression, and caretaker burden (0.33 < r<0.52, ps < 0.03).
UNASSIGNED: While larger datasets are needed to clarify whether PwPs experience more auditory difficulties than healthy controls, our results underscore the importance of considering auditory processing on the symptomatic spectrum of Parkinson\'s disease using standardized replicable methodologies.
It is unknown whether there exists a relationship between Parkinson’s disease (PD) and hearing ability. While some studies have found hearing difficulties to be associated with PD, other studies failed to replicate these effects. We suggest that a possible reason for these differing findings are differences in how hearing is measured. To clarify the literature, we tested a group of people with Parkinson’s (PwPs) on several aspects of hearing using a freely available tablet-based app. We compared PwPs hearing tests to those of an age and education matched group of people without PD. While we found no clear differences among the groups, we did find better hearing abilities were related to less motor symptom severity and depression, better reported quality of life, and less reported burden of the disease experienced by the caretaker. We conclude that while there is no solid evidence showing the hearing is necessarily impaired in PD, that measuring hearing in PwPs can provide valuable clinical information. This can inform new approaches to treatment for people living with PD such as those related with improving hearing.

Sensory experience during development has lasting effects on perception and neural processing. Exposing animals to artificial stimuli early in life influences the tuning and functional organization of the auditory cortex, but less is known about how the rich acoustical environments experienced by vocal communicators affect the processing of complex vocalizations. Here, we show that in zebra finches (Taeniopygia guttata), a colonial-breeding songbird species, exposure to a naturalistic social-acoustical environment during development has a profound impact on cortical-level auditory responses to conspecific song. Compared to birds raised by pairs in acoustic isolation, birds raised in a breeding colony had higher average firing rates, selectivity, and discriminability, especially in the narrow-spiking, putatively inhibitory neurons of a higher-order auditory area, the caudomedial nidopallium (NCM). Neurons in colony-reared birds were also less correlated in their tuning and more efficient at encoding the spectrotemporal structure of conspecific song. These results suggest that the auditory cortex adapts to noisy, complex acoustical environments by strengthening inhibitory circuitry, functionally decoupling excitatory neurons while maintaining overall excitatory-inhibitory balance.

Introduction  The limited access to temporal fine structure (TFS) cues is a reason for reduced speech-in-noise recognition in cochlear implant (CI) users. The CI signal processing schemes like electroacoustic stimulation (EAS) and fine structure processing (FSP) encode TFS in the low frequency whereas theoretical strategies such as frequency amplitude modulation encoder (FAME) encode TFS in all the bands. Objective  The present study compared the effect of simulated CI signal processing schemes that either encode no TFS, TFS information in all bands, or TFS only in low-frequency bands on concurrent vowel identification (CVI) and Zebra speech perception (ZSP). Methods  Temporal fine structure information was systematically manipulated using a 30-band sine-wave (SV) vocoder. The TFS was either absent (SV) or presented in all the bands as frequency modulations simulating the FAME algorithm or only in bands below 525 Hz to simulate EAS. Concurrent vowel identification and ZSP were measured under each condition in 15 adults with normal hearing. Results  The CVI scores did not differ between the 3 schemes (F (2, 28)  = 0.62, p  = 0.55, η 2 p  = 0.04). The effect of encoding TFS was observed for ZSP (F (2, 28)  = 5.73, p  = 0.008, η 2 p  = 0.29). Perception of Zebra speech was significantly better with EAS and FAME than with SV. There was no significant difference in ZSP scores obtained with EAS and FAME ( p  = 1.00) Conclusion  For ZSP, the TFS cues from FAME and EAS resulted in equivalent improvements in performance compared to the SV scheme. The presence or absence of TFS did not affect the CVI scores.

Introduction  In clinical practice, patients with the same degree and configuration of hearing loss, or even with normal audiometric thresholds, present substantially different performances in terms of speech perception. This probably happens because other factors, in addition to auditory sensitivity, interfere with speech perception. Thus, studies are needed to investigate the performance of listeners in unfavorable listening conditions to identify the processes that interfere in the speech perception of these subjects. Objective  To verify the influence of age, temporal processing, and working memory on speech recognition in noise. Methods  Thirty-eight adult and elderly individuals with normal hearing thresholds participated in the study. Participants were divided into two groups: The adult group (G1), composed of 10 individuals aged 21 to 33 years, and the elderly group (G2), with 28 participants aged 60 to 81 years. They underwent audiological assessment with the Portuguese Sentence List Test, Gaps-in-Noise test, Digit Span Memory test, Running Span Task, Corsi Block-Tapping test, and Visual Pattern test. Results  The Running Span Task score proved to be a statistically significant predictor of the listening-in-noise variable. This result showed that the difference in performance between groups G1 and G2 in relation to listening in noise is due not only to aging, but also to changes in working memory. Conclusion  The study showed that working memory is a predictor of listening performance in noise in individuals with normal hearing, and that this task can provide important information for investigation in individuals who have difficulty hearing in unfavorable environments.

During the first year of life, infants start to learn the lexicon of their native language. Word learning includes the establishment of longer-term representations for the phonological form and the meaning of the word in the brain, as well as the link between them. However, it is not known how the brain processes word forms immediately after they have been learned. We familiarized 12-month-old infants (N = 52) with two pseudowords and studied their neural signatures. Specifically, we determined whether a newly learned word form elicits neural signatures similar to those observed when a known word is recognized (i.e., when a well-established word representation is activated, eliciting enhanced mismatch responses) or whether the processing of a newly learned word form shows the suppression of the neural response along with the principles of predictive coding of a learned rule (i.e., the order of the syllables of the new word form). The pattern of results obtained in the current study suggests that recognized word forms elicit a mismatch response of negative polarity, similar to newly learned and previously known words with an established representation in long-term memory. In contrast, prediction errors caused by acoustic novelty or deviation from the expected order in a sequence of (pseudo)words elicit responses of positive polarity. This suggests that electric brain activity is not fully explained by the predictive coding framework.

The zebrafish, a widely used model in neurobiology, relies on hearing in aquatic environments. Unfortunately, its auditory pathways have mainly been studied in larvae. In this study, we examined the involvement of the anterior tuberal nucleus (AT) in auditory processing in adult zebrafish. Our tract-tracing experiments revealed that the dorsal subdivision of AT is strongly bidirectionally connected to the central nucleus of the torus semicircularis (TSc), a major auditory nucleus in fishes. Immunohistochemical visualization of the ribosomal protein S6 (pS6) phosphorylation to map neural activity in response to auditory stimulation substantiated this finding: the dorsal but not the ventral part of AT responded strongly to auditory stimulation. A similar response to auditory stimulation was present in the TSc but not in the nucleus isthmi, a visual region, which we used as a control for testing if the pS6 activation was specific to the auditory stimulation. We also measured the time course of pS6 phosphorylation, which was previously unreported in teleost fish. After auditory stimulation, we found that pS6 phosphorylation peaked between 100 and 130 min and returned to baseline levels after 190 min. This information will be valuable for the design of future pS6 experiments. Our results suggest an anatomical and functional subdivision of AT, where only the dorsal part connects to the auditory network and processes auditory information.

The inferior colliculus (IC), a midbrain hub for integration of auditory information, receives dense cholinergic input that could modulate nearly all aspects of hearing. A key step in understanding cholinergic modulation is to identify the source(s) and termination patterns of cholinergic input. These issues have not been addressed for the IC in mice, an increasingly important model for study of hearing. We examined cholinergic inputs to the IC in adult male and female mice. We used retrograde tracing and immunochemistry to identify three sources of cholinergic innervation of the mouse IC: the pedunculopontine tegmental nucleus (PPT), the laterodorsal tegmental nucleus (LDT) and the lateral paragigantocellular nucleus (LPGi). We then used Cre-dependent labeling of cholinergic neurons in normal-hearing ChAT-Cre mice to selectively label the cholinergic projections to the IC from each of the cholinergic sources. Labeling of cholinergic projections from the PPT and LDT revealed cholinergic axons and boutons terminating throughout the IC, with the ipsilateral projection being denser. Electron microscopic examination showed that these cholinergic axons can form traditional synaptic junctions with IC neurons. In separate experiments, selective labeling of cholinergic projections from the LPGi revealed bilateral projections to the IC. The LPGi axons exhibited relatively equal densities on ipsilateral and contralateral sides, but on both sides the terminations were largely restricted to the non-lemniscal regions of the IC (i.e., the dorsal cortex, lateral cortex and intercollicular tegmentum). We conclude first that cholinergic axons can form traditional synapses in the IC. In addition, lemniscal and non-lemniscal regions of the IC receive different patterns of cholinergic innervation. The lemniscal IC (IC central nucleus) is innervated by cholinergic neurons in the PPT and the LDT whereas the non-lemniscal \"shell\" areas of the IC are innervated by the PPT and LDT and by cholinergic neurons in the LPGi. DATA AVAILABILITY: Data will be made available on request.