As musicians have been shown to have a range of superior auditory skills to non-musicians (e.g., pitch discrimination ability), it has been hypothesized by many researchers that music training can have a beneficial effect on speech perception in populations with hearing impairment. This hypothesis relies on an assumption that the benefits seen in musicians are due to their training and not due to innate skills that may support successful musicianship. This systematic review examined the evidence from 13 longitudinal training studies that tested the hypothesis that music training has a causal effect on speech perception ability in hearing-impaired listeners. The papers were evaluated for quality of research design and appropriate analysis techniques. Only 4 of the 13 papers used a research design that allowed a causal relation between music training and outcome benefits to be validly tested, and none of those 4 papers with a better quality study design demonstrated a benefit of music training for speech perception. In spite of the lack of valid evidence in support of the hypothesis, 10 of the 13 papers made claims of benefits of music training, showing a propensity for confirmation bias in this area of research. It is recommended that future studies that aim to evaluate the association of speech perception ability and music training use a study design that differentiates the effects of training from those of innate perceptual and cognitive skills in the participants.

Objectives Different surgical techniques have been described in the literature to increase vocal pitch. The purpose of this study is to systematically review these surgeries and perform a meta-analysis to determine which technique increases pitch the most. Data Sources CINAHL, Cochrane, Embase, Medline, PubMed, and Science Direct. Review Methods A systematic review and meta-analysis of the literature was performed using the CINAHL, Cochrane, Embase, Medline, PubMed, and Science Direct databases. Studies were eligible for inclusion if they evaluated pitch-elevating phonosurgical techniques in live humans and performed pre- and postoperative acoustic analysis. Data were gathered regarding surgical technique, pre- and postoperative fundamental frequencies, perioperative care measures, and complications. Results Twenty-nine studies were identified. After applying inclusion and exclusion criteria, a total of 13 studies were included in the meta-analysis. Mechanisms of pitch elevation included increasing vocal cord tension (cricothyroid approximation), shortening the vocal cord length (cold knife glottoplasty, laser-shortening glottoplasty), and decreasing mass (laser reduction glottoplasty). The most common interventions were shortening techniques and cricothyroid approximation (6 studies each). The largest increase in fundamental frequency was seen with techniques that shortened the vocal cords. Preoperative speech therapy, postoperative voice rest, and reporting of patient satisfaction were inconsistent. Many of the studies were limited by low power and short length of follow-up. Conclusions Multiple techniques for elevation of vocal pitch exist, but vocal cord shortening procedures appear to result in the largest increase in fundamental frequency.

Patients with schizophrenia display abnormalities in pitch discrimination of non-verbal tones as revealed by the Tone-Matching Task (TMT). It may lead to deficits in higher-order cognitive functions and clinical symptoms.
We conducted a systematic review and meta-analysis pooling data about TMT score differences between patients with schizophrenia and healthy controls, to evaluate the deficit\'s effect size, and to develop reliable knowledge about pitch processing impairment and its pejorative impact.
Relevant publications were identified by a systematic search of PubMed and EMBASE databases. Then, we excluded non-relevant studies for the meta-analysis. Effect size for percent of correct responses to the TMT was expressed as standardized mean difference (SMD).
Eighteen of 167 identified studies met eligibility criteria for review, of which 10 were included in the meta-analysis. Our meta-analysis showed that the effect size for the percent of correct response to the TMT between patients (N=371) and controls (N=342) was large: SMD=1.17 [95% CI: 0.926-1.418] (z-value=9.338 and p-value<0.001). Meta-analysis showed moderate heterogeneity between studies (Q(9)=17.22, p=0.04, I2=47.74%). The relationship between tone-matching impairment and clinical symptoms of schizophrenia remains heterogeneous across studies. Some authors observed significant correlations between tone-matching performance and a number of higher-order cognitive abilities.
This review and meta-analysis highlights a large significant disturbance in tone-matching ability in patients as compared with controls. The study of basic auditory processing opens promising perspectives for pathophysiological modelling of the disorder and therapeutic issues.

OBJECTIVE: The relationship between the auditory system and voice production has been studied extensively in those with impaired hearing, indicating the potential importance of the auditory system to the voice. However, there has been only limited study on the phonatory implications in those with superior auditory systems. This article examines the current literature on the effects of different auditory system characteristics on voice quality and accuracy.
METHODS: The following databases were searched from their inception to November 2013: PubMed, EBSCO, and CINAHL. The following keywords were used: \"hearing impaired,\" \"auditory system,\" \"voice,\" \"professional voice user,\" \"hearing,\" \"singing,\" and \"hearing loss.\" The references of articles were studied to identify further relevant citations. Additionally, Internet searches of Google and Google Scholar were performed. Relevant articles in English were included for review. Studies were excluded on article selection criteria, search strategy followed, search keywords, and searched databases.
CONCLUSIONS: Current literature on the relationship between the auditory system and voice production focuses mostly on the hearing impaired, in which the changes in voice involve alterations in respiration, phonation, and articulation. Evidence on the phonatory effects of a superior auditory system is more limited. There is conflicting evidence as to the existence of a relationship between auditory pitch discrimination and vocal pitch accuracy. The role of the internal model on this relationship and the effects of training on enhancing and modifying the neural areas involved in the model have been studied. Professional singers have also been studied, examining the effects of training on auditory feedback and pitch accuracy. These studies have also produced inconsistent results. Further research is needed.

Echo-locating bats constantly emit ultrasonic pulses and analyze the returning echoes to detect, localize, and classify objects in their surroundings. Echo classification is essential for bats\' everyday life; for instance, it enables bats to use acoustical landmarks for navigation and to recognize food sources from other objects. Most of the research of echo based object classification in echo-locating bats was done in the context of simple artificial objects. These objects might represent prey, flower, or fruit and are characterized by simple echoes with a single up to several reflectors. Bats, however, must also be able to use echoes that return from complex structures such as plants or other types of background. Such echoes are characterized by superpositions of many reflections that can only be described using a stochastic statistical approach. Scientists have only lately started to address the issue of complex echo classification by echo-locating bats. Some behavioral evidence showing that bats can classify complex echoes has been accumulated and several hypotheses have been suggested as to how they do so. Here, we present a first review of this data. We raise some hypotheses regarding possible interpretations of the data and point out necessary future directions that should be pursued.

In the present article, the basic research using the mismatch negativity (MMN) and analogous results obtained by using the magnetoencephalography (MEG) and other brain-imaging technologies is reviewed. This response is elicited by any discriminable change in auditory stimulation but recent studies extended the notion of the MMN even to higher-order cognitive processes such as those involving grammar and semantic meaning. Moreover, MMN data also show the presence of automatic intelligent processes such as stimulus anticipation at the level of auditory cortex. In addition, the MMN enables one to establish the brain processes underlying the initiation of attention switch to, conscious perception of, sound change in an unattended stimulus stream.

Studies using dichotic listening tasks have reported findings suggestive of alterations of cerebral laterality in schizophrenia and affective disorders. In a review of these findings, an effort was made to take into account four factors: (1) type of dichotic listening task; (2) performance level; (3) clinical state of patients at the time of testing; (4) diagnostic subtype of patients. A convergence of evidence indicates that the last two factors are of major importance. Several studies have found a relationship between clinical state and dichotic ear asymmetry. Greater severity of illness in schizophrenic and depressed patients is associated with reduced laterality, and clinical remission is accompanied by a normalization of laterality. While thie relationship appears to hold for both verbal and nonverbal dichotic tasks in depressed patients, that is not the case for schizophrenic patients. Studies have also reported evidence of differences in dichotic ear asymmetry between diagnostic subtypes of schizophrenia (i.e., paranoid vs. nonparanoid patients) and affective disorders (i.e., bipolar vs. unipolar patients). This evidence suggests the existence of homogeneous subgroups with distinctive laterality patterns and clinical characteristics.

This review presents recent findings on the micromechanics of the basilar membrane. Active processes are essential for basilar membrane motion. It may be that contractile proteins within the outer hair cells play an important role for this amplification. The coding of acoustic information within the auditory nerve depends on spectral analysis (place information) as well as on the time structure of the stimulus. This latter time analysis seems to play a major role.

Age related changes in the sensory modalities of hearing and vision, along with changes in the information processing abilities of selective attention, perceptual style, and perceptual-motor reaction time, were reviewed in the context of driving behavior. Literature reported, indicated age related changes in these abilities have relevance for the understanding of the driving behavior of the older adult.