Neuroauriculotherapy: Framework and Remarks for a possible use in Voice Medicine / Neuroauriculoterapia: marco y observaciones para un posible uso en medicina de la voz

Aim. Neuroauriculotherapy (NAT) is a branch of medicine, which, thanks to its diagnostic and therapeutic value, is a powerful tool at the service of both physician and patient. In our experience, as it is discussed in this article, neuroauriculotherapy can have successful applications in voice science and in phoniatrics. The aim of this article is to open a discussion about possible applications of neuroauriculotherapy in voice medicine. Introduction. From the diagnostic point of view, it is possible to explore, with a palpeur (i.e., a tool that provides a constant pressure) or a "spot-hunter", the presence of a perturbation into a particular organ or area, and its return to normal during treatment. Indeed, at the level of the ear auricle, representations of an organ, its in-nervation, its muscular components, etc., are fixed. These spots or voxels correspond absolutely to the respective sensory, motor, visceral, among other spots. Therefore, if any abnormal potential comes from the periphery, it will illuminate the spots both at the cortical level and in the pavilion ­a real display with a constantly active touch screen. The spot can be treated with needles in the context of a neurophysiological strategy to send a message to the brain.Reflection. NAT appears to be a good method to improve the treatment of voice problems, enhancing the results of other therapies based on drugs or rehab and in-ducing relaxation. In neuroauriculotherapy, the ear is used to give the brain orders in a process which has a logical basis in neurophysiology.Conclusion. Diseases of the vocal tract can be dysfunctional or organic. According to our clinical experience, we can say that neuroauriculotherapy can be used in both cases. Neuroauriculotherapy is also extremely effective in voice therapy, both alone and in combination with other therapies, as there is no conflict among them

Objetivo. La neuroauriculoterapia (NAT) es una rama de la medicina que, gracias a su valor diagnóstico y terapéutico, constituye una poderosa herramienta al servicio del médico y del paciente. En nuestra experiencia, como se comenta en este artículo, la neuroauriculoterapia puede tener aplicaciones exitosas en la ciencia de la voz y en foniatría. El objetivo de este artículo es abrir una discusión sobre las posibles aplica-ciones de la neuroauriculoterapia en la medicina de la voz.Introducción. Desde el punto de vista del diagnóstico, es posible explorar, con un palpeur (i.e., una herramienta que proporciona una presión constante) o un "spot-hunter", la presencia de una perturbación en un órgano o área en particular, y su retorno a la normalidad durante el tratamiento. En efecto, a nivel del pabellón auricular se fijan representaciones de un órgano, su inervación, sus componentes musculares, etc. Estos puntos o vóxeles corresponden absolutamente a los respectivos puntos sensoriales, motores, viscerales, entre otros. Por lo tanto, si algún potencial anormal proviene de la periferia, iluminará los puntos tanto a nivel cortical como en el pabellón ­una pantalla real con una pantalla táctil constantemente activa. El punto se puede tratar con agujas en el contexto de una estrategia neurofisiológica para enviar un mensaje al cerebro.Reflexión. NAT parece ser un buen método para mejorar el tratamiento de los problemas de voz, potenciando los resultados de otras terapias basadas en fármacos o rehabilitación e induciendo a la relajación. En neuroauriculoterapia se utiliza el oído para dar órdenes al cerebro en un proceso que tiene una base lógica en la neurofisiología.Conclusión. Las enfermedades del tracto vocal pueden ser disfuncionales u orgáni-cas. Según nuestra experiencia clínica, podemos decir que la neuroauriculoterapia se puede utilizar en ambos casos. La neuroauriculoterapia también es extremadamente eficaz en la terapia de la voz, tanto sola como en combinación con otras terapias, ya que no existe conflicto entre ellas

Immediate effect of non-invasive auricular acupoint stimulation on the performance and meridian activities of archery athletes: A protocol for randomized controlled trial.

BACKGROUND: Archery has existed in human history for millenniums. Being a unique exercise and precision sport, the keys to performance are emotional control, attention, and concentration rather than explosive force, muscle power, and endurance. During the execution of archery, attention is the key to performance in elite players, especially in the initial period while drawing the bow. Auricular acupoint stimulation is one of the therapeutic methods of traditional Chinese medicine and has been reported for its use in amplifying the anesthesia effect, weight reduction, cessation of substance abuse, and autonomic nervous modulation. METHODS: The study will recruit archery players in school teams among junior and senior high schools and colleges. The subjects will be randomly assigned to the ear and sham acupressure groups. This is a randomized controlled trial with crossover design. The outcome measures will be obtained, including the meridian activities and balance index with Ryodoraku device, the movement stability with WIMU tracking system, the continuous heart rate record, and the scores of the 2 sections as the performance. The subjects will rate their attention and fatigue levels through self-reported questionnaires. OBJECTIVES: This study aims to investigate the immediate effect of non-invasive auricular acupoint stimulation on the performance and meridian activities of archery athletes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04637607.

Vestigial auriculomotor activity indicates the direction of auditory attention in humans.

Unlike dogs and cats, people do not point their ears as they focus attention on novel, salient, or task-relevant stimuli. Our species may nevertheless have retained a vestigial pinna-orienting system that has persisted as a 'neural fossil' within in the brain for about 25 million years. Consistent with this hypothesis, we demonstrate that the direction of auditory attention is reflected in sustained electrical activity of muscles within the vestigial auriculomotor system. Surface electromyograms (EMGs) were taken from muscles that either move the pinna or alter its shape. To assess reflexive, stimulus-driven attention we presented novel sounds from speakers at four different lateral locations while the participants silently read a boring text in front of them. To test voluntary, goal-directed attention we instructed participants to listen to a short story coming from one of these speakers, while ignoring a competing story from the corresponding speaker on the opposite side. In both experiments, EMG recordings showed larger activity at the ear on the side of the attended stimulus, but with slightly different patterns. Upward movement (perking) differed according to the lateral focus of attention only during voluntary orienting; rearward folding of the pinna's upper-lateral edge exhibited such differences only during reflexive orienting. The existence of a pinna-orienting system in humans, one that is experimentally accessible, offers opportunities for basic as well as applied science.

Dogs, cats, monkeys and other animals perk their ears in the direction of sounds they are interested in. Humans and their closest ape relatives, however, appear to have lost this ability. Some humans are able to wiggle their ears, suggesting that some of the brain circuits and muscles that allow automatic ear movements towards sounds are still present. This may be a 'vestigial feature', an ability that is maintained even though it no longer serves its original purpose. Now, Strauss et al. show that vestigial movements of muscles around the ear indicate the direction of sounds a person is paying attention to. In the experiments, human volunteers tried to read a boring text while surprising sounds like a traffic jam, a baby crying, or footsteps played. During this exercise, Strauss et al. recorded the electrical activity in the muscles of their ears to see if they moved in response to the direction the sound came from. In a second set of experiments, the same electrical recordings were made as participants listened to a podcast while a second podcast was playing from a different direction. The individuals' ears were also recorded using high resolution video. Both sets of experiments revealed tiny involuntary movements in muscles surrounding the ear closest to the direction of a sound the person is listening to. When the participants tried to listen to one podcast and tune out another, they also made ear 'perking' movements in the direction of their preferred podcast. The results suggest that movements of the vestigial muscles in the human ear indicate the direction of sounds a person is paying attention to. These tiny movements could be used to develop better hearing aids that sense the electrical activity in the ear muscles and amplify sounds the person is trying to focus on, while minimizing other sounds.

Suppression tuning of spontaneous otoacoustic emissions in the barn owl (Tyto alba).

Spontaneous otoacoustic emissions (SOAEs) have been observed in a variety of different vertebrates, including humans and barn owls (Tyto alba). The underlying mechanisms producing the SOAEs and the meaning of their characteristics regarding the frequency selectivity of an individual and species are, however, still under debate. In the present study, we measured SOAE spectra in lightly anesthetized barn owls and suppressed their amplitudes by presenting pure tones at different frequencies and sound levels. Suppression effects were quantified by deriving suppression tuning curves (STCs) with a criterion of 2 dB suppression. SOAEs were found in 100% of ears (n = 14), with an average of 12.7 SOAEs per ear. Across the whole SOAE frequency range of 3.4-10.2 kHz, the distances between neighboring SOAEs were relatively uniform, with a median distance of 430 Hz. The majority (87.6%) of SOAEs were recorded at frequencies that fall within the barn owl's auditory fovea (5-10 kHz). The STCs were V-shaped and sharply tuned, similar to STCs from humans and other species. Between 5 and 10 kHz, the median Q10dB value of STC was 4.87 and was thus lower than that of owl single-unit neural data. There was no evidence for secondary STC side lobes, as seen in humans. The best thresholds of the STCs varied from 7.0 to 57.5 dB SPL and correlated with SOAE level, such that smaller SOAEs tended to require a higher sound level to be suppressed. While similar, the frequency-threshold curves of auditory-nerve fibers and STCs of SOAEs differ in some respects in their tuning characteristics indicating that SOAE suppression tuning in the barn owl may not directly reflect neural tuning in primary auditory nerve fibers.

Combining Education With Auricular Acupressure to Facilitate Smoking Cessation in Young Adults.

Young adults rarely use pharmacotherapy to cease smoking. This prospective experimental study was performed using a nonpharmacotherapy design. Smoking cessation education combined with auricular acupressure may be more attractive. The key factor for superior smoking cessation was the decrease of nicotine dependence in the early stage of smoking cessation.

Local and Global Spatial Organization of Interaural Level Difference and Frequency Preferences in Auditory Cortex.

Despite decades of microelectrode recordings, fundamental questions remain about how auditory cortex represents sound-source location. Here, we used in vivo 2-photon calcium imaging to measure the sensitivity of layer II/III neurons in mouse primary auditory cortex (A1) to interaural level differences (ILDs), the principal spatial cue in this species. Although most ILD-sensitive neurons preferred ILDs favoring the contralateral ear, neurons with either midline or ipsilateral preferences were also present. An opponent-channel decoder accurately classified ILDs using the difference in responses between populations of neurons that preferred contralateral-ear-greater and ipsilateral-ear-greater stimuli. We also examined the spatial organization of binaural tuning properties across the imaged neurons with unprecedented resolution. Neurons driven exclusively by contralateral ear stimuli or by binaural stimulation occasionally formed local clusters, but their binaural categories and ILD preferences were not spatially organized on a more global scale. In contrast, the sound frequency preferences of most neurons within local cortical regions fell within a restricted frequency range, and a tonotopic gradient was observed across the cortical surface of individual mice. These results indicate that the representation of ILDs in mouse A1 is comparable to that of most other mammalian species, and appears to lack systematic or consistent spatial order.

Spontaneous retrieval reveals right-ear advantage in prospective memory.

The goal of this study was to investigate the impact of individual costs on prospective memory performance. Individual costs were assessed by contrasting participants with high costs and those with low costs. Specifically, we tested whether prospective memory performance is moderated by costs, cue-focality and intention specificity. Participants performed a dichotic listening paradigm where they had to indicate whether a word presented to one ear was abstract or concrete while ignoring the word presented to the other ear. For the prospective memory task, participants had to detect target items; half of them were presented focally to the same ear as the relevant words for the ongoing task and half of them were presented non-focally to the other ear. Moreover, half of the participants were given specific instructions and the other half were given categorical instructions. The results revealed a right-ear advantage for participants with low costs but not for participants with high costs. Moreover, the absence of costs was not necessarily accompanied by worse prospective memory performance. Given differential results under the same task conditions, we conclude that individual costs are an important factor which should be considered when investigating prospective memory processes.

Conventional and novel body temperature measurement during rest and exercise induced hyperthermia.

Despite technological advances in thermal sensory equipment, few core temperature (TCORE) measurement techniques have met the established validity criteria in exercise science. Additionally, there is debate as to what method serves as the most practically viable, yet upholds the proposed measurement accuracy. This study assessed the accuracy of current and novel TCORE measurement techniques in comparison to rectal temperature (TREC) as a reference standard. Fifteen well-trained subjects (11 male, 4 female) completed 60min of exercise at an intensity equating to the lactate threshold; measured via a discontinuous exercise test. TREC was significantly elevated from resting values (37.2±0.3°C) at the end of moderate intensity exercise (39.6±0.04°C; P=0.001). Intestinal telemetric pill (TPILL) temperature and temporal artery temperature (TTEM) did not differ significantly from TREC at rest or during exercise (P>0.05). However, aural canal temperature (TAUR) and thermal imaging temperature (TIMA) were both significantly lower than TREC (P<0.05). Bland Altman analysis revealed only TPILL was within acceptable limits of agreement (mean bias; 0.04°C), while TTEM, TAUR and TIMA demonstrated mean bias values outside of the acceptable range (>0.27°C). Against TREC, these results support the use of TPILL over all other techniques as a valid measure of TCORE at rest and during exercise induced hyperthermia. Novel findings illustrate that TIMA (when measured at the inner eye canthus) shows poor agreement to TREC during rest and exercise, which is similar to other 'surface' measures.

[Tinnitus caused by heart disease and healed from heart].

Tinnitus is recognized as a refractory disease, which is common in clinic, and always treated from the liver and kidney. We treat tinnitus mainly by heart based on syndrome differentiation. It often works well when the left cukou pulse is abnormal. Referring to ancient literature, we find that the heart is related to ears by meridians, and the kidney and heart govern ears. The normal function of heart and kidney means normal hearing. The heart secretes atrial natriuretic polypeptins (ANP), whose receptor is widely distributed in ears and can increase the cochlear blood flow. In this paper we explore the relationship between the heart and the ears so as to provide theories of treatment by heart for tinnitus.

Effect of carrier bandwidth on integration of simulations of acoustic and electric hearing within or across ears.

Differences in current spread and/or spread of excitation may differently affect integration of acoustic and electric hearing within (electric-acoustic stimulation, or EAS) or across ears (bimodal). In this study, vowel recognition was measured in normal-hearing subjects listening to simulations of cochlear implant (CI), EAS, and bimodal listening. Residual acoustic hearing was limited between 0.1 and 0.6 kHz. The carrier bandwidth in the CI simulations was varied across carriers: broad-band noise, narrow-band noise, and sine waves. Results showed that reducing the bandwidth (and the inherent noise fluctuations) in the CI simulations significantly affected CI-only and bimodal performance, but not EAS performance.

Extended bandwidth real-ear measurement accuracy and repeatability to 10 kHz.

OBJECTIVE: Direct real-ear measurement to the 4-6 kHz range can be measured with suitable accuracy and repeatability. This study evaluates extended bandwidth measurement accuracy and repeatability using narrowband and wideband signal analysis. DESIGN: White noise was measured in female ear canals at four insertion depths using one-third and one-twenty-fourth octave band averaging. STUDY SAMPLE: Fourteen female adults with reported normal hearing and middle-ear function participated in the study. RESULTS: Test-retest differences were within ±2 dB for typical frequency bandwidths at insertion depths administered in clinical practice, and for up to 8 kHz at the experimental 30 mm insertion depth. The 28 mm insertion depth was the best predictor of ear canal levels measured at the 30 mm insertion depth. There was no effect of signal analysis bandwidth on accuracy or repeatability. CONCLUSIONS: Clinically feasible 28 mm probe tube insertions reliably measured up to 8 kHz and predicted intensities up to 10 kHz measured at the 30 mm insertion depth more accurately than did shallower insertion depths. Signal analysis bandwidth may not be an important clinical issue at least for one-third and one-twenty-fourth octave band analyses.

Electrical Stimulation of the Ear, Head, Cranial Nerve, or Cortex for the Treatment of Tinnitus: A Scoping Review.

Tinnitus is defined as the perception of sound in the absence of an external source. It is often associated with hearing loss and is thought to result from abnormal neural activity at some point or points in the auditory pathway, which is incorrectly interpreted by the brain as an actual sound. Neurostimulation therapies therefore, which interfere on some level with that abnormal activity, are a logical approach to treatment. For tinnitus, where the pathological neuronal activity might be associated with auditory and other areas of the brain, interventions using electromagnetic, electrical, or acoustic stimuli separately, or paired electrical and acoustic stimuli, have been proposed as treatments. Neurostimulation therapies should modulate neural activity to deliver a permanent reduction in tinnitus percept by driving the neuroplastic changes necessary to interrupt abnormal levels of oscillatory cortical activity and restore typical levels of activity. This change in activity should alter or interrupt the tinnitus percept (reduction or extinction) making it less bothersome. Here we review developments in therapies involving electrical stimulation of the ear, head, cranial nerve, or cortex in the treatment of tinnitus which demonstrably, or are hypothesised to, interrupt pathological neuronal activity in the cortex associated with tinnitus.

Auricular acupuncture diagnosis in patients with lumbar hernia.

BACKGROUND: Auricular Acupuncture Diagnosis is a diagnostic method which is essential for the topographic identification on the auricle of the anatomical parts of the body carrying a particular ailment or dysfunction. OBJECTIVE: To identify the specific zones related to lumbar hernia in patients treated with a series of epidural infiltrations with corticosteroids. METHODS: In a consecutive group of thirty patients with lumbar hernia 2 diagnostic methods used in Auricular Acupuncture Diagnosis, Pain Pressure Test and Electric Skin Resistance Test, were applied before the first infiltration (T0), before the second and the third infiltration (T1, T2) and one week after the third infiltration (T3). The parameters, whose variations were analyzed at T0-T3, were the following: the number of points identified; the intensity of pain on a verbal rating scale and the foot-hand distance in cm with bent spine and extended knees. The identified points were reported on the Auricular Sectogram which is a validated graphic system suitable for a correct transcription of the points and indicated for a statistical analysis of their distribution on the different sectors. RESULTS: A significant association was found for some auricular areas, along the series of epidural infiltrations, with a progressive reduction in the number of tender and low electrical resistance points together with a decrease of pain and hand-foot distance. CONCLUSIONS: The auricular zones found with Auricular Acupuncture Diagnosis in our group of patients seem of clinical relevance and could be included in the complementary treatment of lumbar-sciatic pain in lumbar hernia.

Evaluation of Reflexology by "BIOCERAMIC Resonance" Operation producing Weak Force Field during Simultaneous Acupoint Stimulation of Urinary Bladder Point on Subject's Ear Resulting in Electric Current Change on Urinary Bladder reflex Point on Subject's Hands, and Related New Research Finding.

OBJECTIVE: It was postulated in our previous publications that the meridian channels as conceived in Traditional Chinese Medicine (TCM) are various standing waves arising from harmonic rhythmic sound frequencies originating from the human heart beat. BIOCERAMIC is an artificial material able to produce a weak force field causing different biophysical and systemic health benefits, with the key characteristics of hydrogen bonds weakening and microcirculation enhancement. Since discovering that the effects of a BIOCERAMIC field can be transmitted via sound waves propagation, we then also developed a BIOCERAMIC Resonance device to produce weak force field throughout the body, and achieve resonance with the body's meridian channels to reinforce microcirculation. METHODS: Since our previous research proved BIOCERAMIC can produces changes in ectodermal current levels, the present evaluation on reflexology is done by the application of Electric Current Detection (ECD) to the palmar surface of the hands matching correlative organs and glands loci to reflex points according to standard reflexology. The procedure will compare changes in the electrical current observed before and after a session of BIOCERAMIC Resonance treatment on the soles of the subjects' feet. We also conducted a procedure using corona discharge (Kirlian) photography of the hands to examine whether the coronal intensities could be affected by application of the BIOCERAMIC patch. Intensities are shown on the screen of a computer using special software that categorizes intensities into five zones. RESULTS: Under the continuous treatment of BIOCERAMIC Resonance on soles of the feet and simultaneous stimulation on the specific point on the surface of the ear representing the urinary bladder. The electrical current (Aji ampere) on the areas in the hands are decreased from the beginning of the experiment, but only the specific area on the surface of the ear representing the urinary bladder was exhibited increased of the electrical current (Aji ampere), with statistically significant difference (p<0.05). To the other study we evaluated the validity of reflexology and corona discharge (Kirlian) photography by applying BIOCERAMIC Resonance and small adhesive patches made from the BIOCERAMIC material. Significant differences were evident on four out of five different zones of the computerized images. CONCLUSION: Our findings suggest the existence of presupposed virtual channels or reflex points on the skin surface of the feet, hands, and ears that connect or somehow reflect back to specific internal organs, as mapped out on standard charts found in reflexology. Furthermore, the depicted corona intensities from five zones shown on a computer screen of corona discharge photography seem to indicate that the volunteer subjects are affected by the BIOCERAMIC patches. This study demonstrates the operation of the BIOCERAMIC Resonance device is able to produce weak force field through the body, which is objectively measurable and thereby scientifically integrating the concepts of reflexology, meridian channels and biofield therapy.

The biological significance of acoustic stimuli determines ear preference in the music frog.

Behavioral and neurophysiological studies support the idea that right ear advantage (REA) exists for perception of conspecific vocal signals in birds and mammals. Nevertheless, few studies have focused on anuran species that typically communicate through vocalization. The present study examined the direction and latencies of orientation behaviors in Emei music frogs (Babina daunchina) produced in response to six auditory stimuli emitted by a speaker placed directly behind the subjects. The stimuli included male advertisement calls produced from within burrow nests, which have been shown to be highly sexually attractive (HSA), calls produced from outside burrows, which are of low sexual attractiveness (LSA), screech calls produced when frogs are attacked by snakes, white noise, thunder and silence. For all sound stimuli except the screech, the frogs preferentially turned to the right. Right ear preference was strongest for HSA calls. For the screech and thunder stimuli, there was an increased tendency for subjects to move further from the speaker rather than turning. These results support the idea that in anurans, right ear preference is associated with perception of positive or neutral signals such as the conspecific advertisement call and white noise, while a left ear preference is associated with perception of negative signals such as predatory attack.

Further tests of the local nonlinear interaction-based mechanism for simultaneous suppression of tone burst-evoked otoacoustic emissions.

Tone burst-evoked otoacoustic emission (TBOAE) components measured in response to a 1 kHz tone burst (TB1) are suppressed by the simultaneous presence of an additional tone burst (TB2). This "simultaneous suppression of TBOAEs" has been explained in terms of a mechanism based on local nonlinear interactions between the basilar membrane (BM) travelling waves caused by TB1 and TB2. A test of this local nonlinear interaction (LNI)-based mechanism, as a function of the frequency separation (Δf, expressed in kHz) between TB1 and TB2, has previously been reported by Killan et al. (2012) using a simple mathematical model [Killan et al., Hear. Res. 285, 58-64 (2012)]. The two experiments described in this paper add additional data on the extent to which the LNI-based mechanism can account for simultaneous suppression, by testing two further hypotheses derived from the model predictions. Experiment I tested the hypothesis that TBOAE suppression is directly linked to TBOAE amplitude nonlinearity where ears that exhibit a higher degree of amplitude nonlinearity yield greater suppression than more linear ears, and this relationship varies systematically as a function of Δf. In order to test this hypothesis simultaneous suppression at a range of values of Δf at 60 dB peak-equivalent sound pressure level (p.e. SPL) and TBOAE amplitude nonlinearity from normal human ears was measured. In Experiment II the hypothesis that suppression will also increase progressively as a function of increasing tone burst level was tested by measuring suppression for a range of Δf and tone burst levels at 40, 50, 60 and 70 dB p.e. SPL. The majority of the findings from both experiments provide support for the LNI-based mechanism being primarily responsible for simultaneous suppression. However, some data were inconsistent with this view. Specifically, a breakdown in the relationship between suppression and TBOAE amplitude nonlinearity at Δf = 1 (i.e. when TB2 was reasonably well separated from, and had a higher frequency than TB1) and unexpected level-dependence, most notably at Δf = 1, but also where Δf = -0.5, was observed. Either the LNI model is too simple or an alternative explanation, involving response components generated at basal regions of the basilar membrane, is required to account for these findings.

Asymmetry of temporal auditory T-complex: right ear-left hemisphere advantage in Tb timing in children.

OBJECTIVE: To investigate brain asymmetry of the temporal auditory evoked potentials (T-complex) in response to monaural stimulation in children compared to adults. METHODS: Ten children (7 to 9 years) and ten young adults participated in the study. All were right-handed. The auditory stimuli used were tones (1100 Hz, 70 dB SPL, 50 ms duration) delivered monaurally (right, left ear) at four different levels of stimulus onset asynchrony (700-1100-1500-3000 ms). Latency and amplitude of responses were measured at left and right temporal sites according to the ear stimulated. RESULTS: Peaks of the three successive deflections (Na-Ta-Tb) of the T-complex were greater in amplitude and better defined in children than in adults. Amplitude measurements in children indicated that Na culminates on the left hemisphere whatever the ear stimulated whereas Ta and Tb culminate on the right hemisphere but for left ear stimuli only. Peak latency displayed different patterns of asymmetry. Na and Ta displayed shorter latencies for contralateral stimulation. The original finding was that Tb peak latency was the shortest at the left temporal site for right ear stimulation in children. Amplitude increased and/or peak latency decreased with increasing SOA, however no interaction effect was found with recording site or with ear stimulated. CONCLUSION: Our main original result indicates a right ear-left hemisphere timing advantage for Tb peak in children. The Tb peak would therefore be a good candidate as an electrophysiological marker of ear advantage effects during dichotic stimulation and of functional inter-hemisphere interactions and connectivity in children.

A model that predicts the binaural advantage to speech intelligibility from the mixed target and interferer signals.

A model is presented that predicts the binaural advantage to speech intelligibility by analyzing the right and left recordings at the two ears containing mixed target and interferer signals. This auditory-inspired model implements an equalization-cancellation stage to predict the binaural unmasking (BU) component, in conjunction with a modulation-frequency estimation block to estimate the "better ear" effect (BE) component of the binaural advantage. The model's performance was compared to experimental data obtained under anechoic and reverberant conditions using a single speech-shaped noise interferer paradigm. The internal BU and BE components were compared to those of the speech intelligibility model recently proposed by Lavandier et al. [J. Acoust. Soc. Am. 131, 218-231 (2012)], which requires separate inputs for target and interferer. The data indicate that the proposed model provides comparably good predictions from a mixed-signals input under both anechoic and reverberant conditions.

Sensitivity to envelope-based interaural delays at high frequencies: center frequency affects the envelope rate-limitation.

Sensitivity to ongoing interaural temporal disparities (ITDs) was measured using bandpass-filtered pulse trains centered at 4600, 6500, or 9200 Hz. Save for minor differences in the exact center frequencies, those target stimuli were those employed by Majdak and Laback [J. Acoust. Soc. Am. 125, 3903-3913 (2009)]. At each center frequency, threshold ITD was measured for pulse repetition rates ranging from 64 to 609 Hz. The results and quantitative predictions by a cross-correlation-based model indicated that (1) at most pulse repetition rates, threshold ITD increased with center frequency, (2) the cutoff frequency of the putative envelope low-pass filter that determines sensitivity to ITD at high envelope rates appears to be inversely related to center frequency, and (3) both outcomes were accounted for by assuming that, independent of the center frequency, the listeners' decision variable was a constant criterion change in interaural correlation of the stimuli as processed internally. The finding of an inverse relation between center frequency and the envelope rate limitation, while consistent with much prior literature, runs counter to the conclusion reached by Majdak and Laback.

Binaural detection with narrowband and wideband reproducible noise maskers. IV. Models using interaural time, level, and envelope differences.

The addition of out-of-phase tones to in-phase noises results in dynamic interaural level difference (ILD) and interaural time difference (ITD) cues for the dichotic tone-in-noise detection task. Several models have been used to predict listeners' detection performance based on ILD, ITD, or different combinations of the two cues. The models can be tested using detection performance from an ensemble of reproducible-noise maskers. Previous models cannot predict listeners' detection performance for reproducible-noise maskers without fitting the data. Here, two models were tested for narrowband and wideband reproducible-noise experiments. One model was a linear combination of ILD and ITD that included the generally ignored correlation between the two cues. The other model was based on a newly proposed cue, the slope of the interaural envelope difference (SIED). Predictions from both models explained a significant portion of listeners' performance for detection of a 500-Hz tone in wideband noise. Predictions based on the SIED approached the predictable variance in the wideband condition. The SIED represented a nonlinear combination of ILD and ITD, with the latter cue dominating. Listeners did not use a common strategy (cue) to detect tones in the narrowband condition and may use different single frequencies or different combinations of frequency channels.