Effects Of Auditory Deprivation Research Articles

Congenital deafness reduces alpha-gamma cross-frequency coupling in the auditory cortex

Neurons within a neuronal network can be grouped by bottom-up and top-down influences using synchrony in neuronal oscillations. This creates the representation of perceptual objects from sensory features. Oscillatory activity can be differentiated into stimulus-phase-locked (evoked) and non-phase-locked (induced). The former is mainly determined by sensory input, the latter by higher-level (cortical) processing. Effects of auditory deprivation on cortical oscillations have been studied in congenitally deaf cats (CDCs) using cochlear implant (CI) stimulation. CI-induced alpha, beta, and gamma activity were compromised in the auditory cortex of CDCs. Furthermore, top-down information flow between secondary and primary auditory areas in hearing cats, conveyed by induced alpha oscillations, was lost in CDCs. Here we used the matching pursuit algorithm to assess components of such oscillatory activity in local field potentials recorded in primary field A1. Additionally to the loss of induced alpha oscillations, we also found a loss of evoked theta activity in CDCs. The loss of theta and alpha activity in CDCs can be directly related to reduced high-frequency (gamma-band) activity due to cross-frequency coupling. Here we quantified such cross-frequency coupling in adult 1) hearing-experienced, acoustically stimulated cats (aHCs), 2) hearing-experienced cats following acute pharmacological deafening and subsequent CIs, thus in electrically stimulated cats (eHCs), and 3) electrically stimulated CDCs. We found significant cross-frequency coupling in all animal groups in > 70% of auditory-responsive sites. The predominant coupling in aHCs and eHCs was between theta/alpha phase and gamma power. In CDCs such coupling was lost and replaced by alpha oscillations coupling to delta/theta phase. Thus, alpha/theta oscillations synchronize high-frequency gamma activity only in hearing-experienced cats. The absence of induced alpha and theta oscillations contributes to the loss of induced gamma power in CDCs, thereby signifying impaired local network activity.

Effect of auditory deprivation on adaptive locomotion: Interaction with lower visual field occlusion

Auditory stimuli have been suggested to play a role in adequately controlling movement; however, their influence is not fully understood, particularly regarding dynamic behaviors, such as adaptive locomotion. This study aimed to investigate whether auditory deprivation affects adaptive locomotion. In particular, we aimed to elucidate the role of the auditory sense in obstacle avoidance by manipulating the visual field, which provides crucial sensory information for movement control. Sixteen participants approached a 15-cm obstacle located 6 m away and stepped over it under four different conditions that combined two factors: the hearing condition controlled by wearing earmuffs with and without holes, and the lower visual field condition controlled by carrying opaque white and transparent boards. Spatiotemporal variables during the approach to the obstacle were measured using an electronic walkway, whereas foot clearance over the obstacle was assessed using a motion-capture system. Participants who experienced auditory deprivation and lower visual field occlusion demonstrated greater variability in step length when approaching the obstacle compared with the other conditions. The leading and trailing foot clearances were higher under lower visual field occlusion conditions. Furthermore, when participants were under conditions of auditory deprivation, greater variability was observed in the clearance of the leading foot. These results suggest that auditory information contributes to movement stabilization during adaptive locomotion. Our findings provide evidence that auditory and visual senses complement each other during motor actions, indicating that adaptive locomotion can be influenced by the integration of multiple sensory inputs.

Effect of auditory deprivation on threshold of sound lateralization

Objective This study aimed to investigate the relationship between auditory deprivation and sound lateralisation. Methods This study consisted of a control group (6 female, 4 male) and four study groups (17 female, 19 male) classified according to the participant’s speech discrimination scores (Group 1, above 80%; Group 2, 60–80%; Group 3, 40-60%; and Group 4, below 40%). The lateralisation acuity of the participants was evaluated in a sound-booth room using two loudspeakers. First, the sounds were given equally from both loudspeakers. Later, the point where participants noticed the sound asymmetry between the two speakers was investigated for 250–8000 Hz. Results There was no significant difference in lateralisation thresholds of the participants between groups 1 and group 2 compared to the control group while there was in groups 3 and 4 (p < 0.001). In addition, only the difference between group 4 and the control group was statistically significant (p < 0.05) in the effect of the mental state on test performance. Pearson’s correlation test results showed a medium correlation between the mental test and lateralisation thresholds with speech stimuli and at all frequencies (min-max:44.6 − 51.3%). Conlusions A strong correlation was observed between the auditory discrimination scores and lateralisation thresholds at all frequencies.

Cross-modal motion aftereffects transfer between vision and touch in early deaf adults

Previous research on early deafness has primarily focused on the behavioral and neural changes in the intact visual and tactile modalities. However, how early deafness changes the interplay of these two modalities is not well understood. In the current study, we investigated the effect of auditory deprivation on visuo-tactile interaction by measuring the cross-modal motion aftereffect. Consistent with previous findings, motion aftereffect transferred between vision and touch in a bidirectional manner in hearing participants. However, for deaf participants, the cross-modal transfer occurred only in the tactile-to-visual direction but not in the visual-to-tactile direction. This unidirectional cross-modal motion aftereffect found in the deaf participants could not be explained by unisensory motion aftereffect or discrimination threshold. The results suggest a reduced visual influence on tactile motion perception in early deaf individuals.

The Effect of Monaurally Fitted Hearing Aid Use on the Evolution of Presbycusis.

The effect of hearing aid use on the evolution of presbycusis has not been well described in the literature, with only a handful of publications addressing this topic. This paper aims to evaluate the long-term use of amplification and its effect on pure-tone thresholds and word recognition scores. Monaurally fitted patients were followed with serial audiograms. Data was collected from hearing aid centers. Seventy-seven patients with presbycusis met the inclusion criteria and participated in the present study. The progression of hearing loss in both pure tone thresholds and word recognition scores were compared between the hearing aid ears (HA), and the non-hearing aid ears (NHA). Pure tone thresholds were analyzed by comparing the pure tone average at the initial and last audiograms. Word Recognition Scores (WRS) were analyzed using the model of Thornton and Raffin (1978), and by comparing the change in the absolute values of WRS from the initial to the last audiogram between the HA ear and the NHA ear. No significant difference in pure-tone thresholds between the HA ear and NHA ear was found at the last audiogram (P = .696), even after dividing the patients into groups based on the duration of amplification. Both methods of analysis of patients' WRS showed a statistically significant worsening in NHA (P < .05). The present study supports the previously defined auditory deprivation effect on non-fitted ears, which showed worsening of word recognition over time and no effect on pure tone average. It provides an additional argument for the counseling of patients with presbycusis considering amplification, and highlights the importance of bilateral amplification in preserving the residual hearing of hearing impaired patients.

Reorganized Brain White Matter in Early- and Late-Onset Deafness With Diffusion Tensor Imaging.

Individuals with early- and late-onset deafness showed different functional and morphological brain changes, but white matter alterations in both deaf groups still need to be elucidated. This study aimed to investigate changes in white matter integrity and white matter anatomical connectivity in both early- and late-onset deaf groups compared with hearing group. Diffusion tensor imaging data from 7 early-onset deaf (50.7 ± 6.5 years), 11 late-onset deaf (50.9 ± 12.3 years), and 9 hearing adults (48.9 ± 9.5 years) were preprocessed using FSL software. To find changes in white matter integrity, tract-based spatial statistics was used, which implemented on FSL software. Fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) were calculated and compared among the groups with age as a nuisance variable. To find out the effect of onset age or duration of deafness to the white matter integrity, onset-age or duration of deafness was treated as a variable of interest in the general linear model implemented on tract-based spatial statistics. White matter connectivity was constructed by a deterministic tractography and compared among the groups. In comparison to the hearing group, the early-onset deaf group did not show any significant changes but the late-onset deaf group showed decreased FA and increased RD in the several white matter areas. AD in the late-onset deaf group was not significantly different compared with the hearing group. The regions included the corpus callosum, posterior and superior corona radiata, internal capsule, posterior thalamic radiation, superior longitudinal fasciculus, and tapetum of the right hemisphere. Increased RD was also additionally observed in the right external capsule, fornix, and cerebral peduncle. The onset age or duration of deafness was not significantly correlated with the white matter integrity in the early-onset deaf group. In contrast, the onset age showed a significantly positive correlation with the RD, and a negative correlation with the FA, in the late-onset deaf group. The correlated white matter areas were also similar to the findings of comparison with the hearing group. In comparison to the hearing group, the early-onset deaf group did not show altered white matter connectivity, while the late-onset deaf group showed decreased white matter connectivity in between the right lingual and hippocampal areas. The present results suggest that late-onset deaf adults showed decreased FA and increased RD, and early-onset deaf adults showed no difference compared with the hearing group. In the late-onset deaf adults, onset-age showed a significantly positive correlation with RD and negative correlation with FA. Duration of deafness was not significantly correlated with the changes. Increased RD indicating demyelination occurred in the brain, and the changes were not limited to the auditory cortex but expanded to almost whole brain areas, suggesting significant effect of auditory deprivation on the brain later in life. The altered white matter connectivity in between the right limbic-occipital areas observed in the late-onset deaf group might be caused by altered language functions after auditory deprivation. Future studies are necessary incorporating functional and anatomical aspects of the brain changes in deaf group.

Research Insights on Neural Effects of Auditory Deprivation and Restoration in Unilateral Hearing Loss: A Systematic Review.

Neuroplasticity following bilateral deafness and auditory restoration has been repeatedly investigated. In clinical practice, however, a significant number of patients present a severe-to-profound unilateral hearing loss (UHL). To date, less is known about the neuroplasticity following monaural hearing deprivation and auditory input restoration. This article provides an overview of the current research insights on the impact of UHL on the brain and the effect of auditory input restoration with a cochlear implant (CI). An exhaustive systematic review of the literature was performed selecting 38 studies that apply different neural analyses techniques. The main results show that the hearing ear becomes functionally dominant after monaural deprivation, reshaping the lateralization of the neural network for auditory processing, a process that can be considered to influence auditory restoration. Furthermore, animal models predict that the onset time of UHL impacts auditory restoration. Hence, the results seem to advocate for early restoration of UHL, although further research is required to disambiguate the effects of duration and onset of UHL on auditory restoration and on structural neuroplasticity following UHL deprivation and restoration. Ongoing developments on CI devices compatible with Magnetic Resonance Imaging (MRI) examinations will provide a unique opportunity to investigate structural and functional neuroplasticity following CI restoration more directly.

Activity-Dependent Neurodegeneration and Neuroplasticity of Auditory Neurons Following Conductive Hearing Loss in Adult Mice.

We examined the functional and structural changes of auditory neurons (ANs) in adult mice after conductive hearing loss (CHL). Earplugs (EPs) were bilaterally inserted in male 8-week-old mice for 4weeks [EP(+) group] and subsequently removed for 4weeks [EP(+/-) group]. We examined the control mice [EP(-) group] with no EPs inserted at 12weeks. The auditory brainstem response (ABR) was measured to determine the cochlear function before and after EP insertion, after EP removal, and at 4weeks following EP removal. We examined the cochleae for hair cell (HC) and spiral ganglion neuron survival, synaptic and neural properties, and AN myelination. There was a significant elevation of the ABR threshold across all tested frequencies after EP insertion. After removing the occlusion, these threshold shifts were fully recovered. Compared with the EP(-) mice, the EP(+) mice showed a significant decrease in the ABR peak 1 amplitude and a significantly prolonged latency at all tested frequencies. There was no significant effect of auditory deprivation on the survival of HCs and ANs. Conversely, auditory deprivation caused significant damage to the synapses and myelin and a significant decrease in the AN size. Although functional changes in the ABR amplitude and latency did not fully recover in the EP(+/-) mice, almost all anatomical changes were fully recovered in the EP(+/-) mice; however, cochlear synapses only showed partial recovery. These results suggest that auditory activities are required to maintain peripheral auditory synapses and myelination in adults. The auditory deprivation model allows for assessment of the mechanisms of synaptopathy and demyelination in the auditory periphery, and synaptic and myelin regeneration in sensorineural hearing loss.

Cochlear implants before 9months of age led to more natural spoken language development without increased surgical risks.

Evidence suggests that cochlear implants are beneficial for language development, but there is no consensus about the ideal age for surgery. We investigated how language development and surgical safety were affected by patients' ages. This study comprised 103 children (52 boys) aged 4.3-16years who received cochlear implants at 5-29months at the Karolinska University Hospital, Stockholm, Sweden, between 2002 and 2013. All showed typical development and were from monolingual homes. Bilateral implants were common (95%). The children were regularly assessed on language understanding, vocabulary and speech recognition by a multi-disciplinary team for 10.0±3.7 (4.7-16.0) years. There were no associations between complications after surgery and the age when children had their first implant. Children implanted at 5-11months reached an age-equivalent level of language understanding and better vocabulary outcome sooner than subgroups implanted later. Children who had surgery at 12-29months demonstrated more atypical and delayed language abilities over time. Early implantation, preferably before 9months, may lead to a more typical trajectory of spoken language development. Our findings showed that cochlear implantation before 9months was safe. Early implantation may reduce the negative effects of auditory deprivation and promotes more natural and synchronised language development.

Auditory and Audiovisual Close Shadowing in Post-Lingually Deaf Cochlear-Implanted Patients and Normal-Hearing Elderly Adults.

The goal of this study was to determine the effect of auditory deprivation and age-related speech decline on perceptuo-motor abilities during speech processing in post-lingually deaf cochlear-implanted participants and in normal-hearing elderly (NHE) participants. A close-shadowing experiment was carried out on 10 cochlear-implanted patients and on 10 NHE participants, with two groups of normal-hearing young participants as controls. To this end, participants had to categorize auditory and audiovisual syllables as quickly as possible, either manually or orally. Reaction times and percentages of correct responses were compared depending on response modes, stimulus modalities, and syllables. Responses of cochlear-implanted subjects were globally slower and less accurate than those of both young and elderly normal-hearing people. Adding the visual modality was found to enhance performance for cochlear-implanted patients, whereas no significant effect was obtained for the NHE group. Critically, oral responses were faster than manual ones for all groups. In addition, for NHE participants, manual responses were more accurate than oral responses, as was the case for normal-hearing young participants when presented with noisy speech stimuli. Faster reaction times were observed for oral than for manual responses in all groups, suggesting that perceptuo-motor relationships were somewhat successfully functional after cochlear implantation and remain efficient in the NHE group. These results are in agreement with recent perceptuo-motor theories of speech perception. They are also supported by the theoretical assumption that implicit motor knowledge and motor representations partly constrain auditory speech processing. In this framework, oral responses would have been generated at an earlier stage of a sensorimotor loop, whereas manual responses would appear late, leading to slower but more accurate responses. The difference between oral and manual responses suggests that the perceptuo-motor loop is still effective for NHE subjects and also for cochlear-implanted participants, despite degraded global performance.

Early unilateral cochlear implantation promotes mature cortical asymmetries in adolescents who are deaf.

Unilateral cochlear implant (CI) stimulation establishes hearing to children who are deaf but compromises bilateral auditory development if a second implant is not provided within ∼ 1.5 years. In this study we asked: 1) What are the cortical consequences of missing this early sensitive period once children reach adolescence? 2) What are the effects of unilateral deprivation on the pathways from the opposite ear? Cortical responses were recorded from 64-cephalic electrodes within the first week of bilateral CI activation in 34 adolescents who had over 10 years of unilateral right CI experience and in 16 normal hearing peers. Cortical activation underlying the evoked peaks was localized to areas of the brain using beamformer imaging. The first CI evoked activity which was more strongly lateralized to the contralateral left hemisphere than normal, with abnormal recruitment of the left prefrontal cortex (involved in cognition/attention), left temporo-parietal-occipital junction (multi-modal integration), and right precuneus (visual processing) region. CI stimulation in the opposite deprived ear evoked atypical cortical responses with abnormally large and widespread dipole activity across the cortex. Thus, using a unilateral CI to hear beyond the period of cortical maturation causes lasting asymmetries in the auditory system, requires recruitment of additional cortical areas to support hearing, and does little to protect the unstimulated pathways from effects of auditory deprivation. The persistence of this reorganization into maturity could signal a closing of a sensitive period for promoting auditory development on the deprived side.

Temporal entrainment of visual attention in children: effects of age and deafness.

The major documented effect of auditory deprivation on visual processing is enhanced spatial attention, in particular to the visual periphery and to moving stimuli. However, there is a parallel literature that has reported deficits in temporal aspects of visual processing in individuals with profound hearing losses. This study builds upon previous work showing possible deficits in processing of rapid serial visual presentation streams in deaf children [Restorative Neurology and Neuroscience (2010), 28, 181-192]. Deaf native signers of American Sign Language and hearing children and adults were asked to perform a 2-AFC identification task with a visual target embedded in a stream of visual stimuli presented at 6 Hz. Both children and adults displayed attentional awakening, whereby target identification accuracy improved as the number of stimuli preceding the target increased. For deaf children, however, this awakening effect was less pronounced than that observed in hearing children, interpreted as difficulty sustaining entrainment to the stimulus stream. The data provide the first account of attentional awakening in children, showing that it improves across the 6-13 year age range. They also provide additional support to the possibility of domain-general alterations in the processing of temporal information in the absence of auditory input.

Development of attention networks in deaf children: Support for the integrative hypothesis

Early auditory deprivation is known to affect visual attention, yet the early effects of auditory deprivation on visual attention cannot be described simply as deficiencies or enhancements, because selected aspects of visual attention could be modified in various ways along the developmental trajectory. However, few studies have explored the development of these various aspects of visual attention in deaf children. In this paper we study the developmental trajectory of three aspects of visual attention (alerting, orienting and executive control attention networks) in a group of deaf children between 6 and 12 years of age. We used the attention network test to explore the development of the three attention networks and a child-friendly version of the cost-benefit paradigm to characterize the development of the basic operations of orienting. Our results showed a pattern of specific but varied outcomes with respect to the effects of auditory deprivation on these attention networks. First, auditory deprivation can impair development of the alerting network. Second, auditory deprivation can enhance two elementary operations of orienting: moving and engaging. Third, the executive control network showed a developmental trajectory that was neither deficient nor enhanced, but rather similar to that observed with hearing children. Taken together, these results are consistent with the integrative hypothesis of the effects of auditory deprivation on visual attention.

Executive Functioning Skills in Long-Term Users of Cochlear Implants: A Case Control Study

To investigate differences in executive functioning between deaf children with cochlear implants (CIs) and normal-hearing (NH) peers. The cognitive effects of auditory deprivation in childhood may extend beyond speech-language skills to more domain-general areas including executive functioning. Executive functioning skills in a sample of 53 prelingually deaf children, adolescents, and young adults who received CIs prior to age 7 years and who had used their CIs for ≥7 years were compared with age- and nonverbal IQ-matched NH peers and with scale norms. Despite having above average nonverbal IQ, the CI sample scored lower than the NH sample and test norms on several measures of short-term/working memory, fluency-speed, and inhibition-concentration. Executive functioning was unrelated to most demographic and hearing history characteristics. Prelingual deafness and long-term use of CIs was associated with increased risk of weaknesses in executive functioning.

Hearing Shapes Our Perception of Time: Temporal Discrimination of Tactile Stimuli in Deaf People

Confronted with the loss of one type of sensory input, we compensate using information conveyed by other senses. However, losing one type of sensory information at specific developmental times may lead to deficits across all sensory modalities. We addressed the effect of auditory deprivation on the development of tactile abilities, taking into account changes occurring at the behavioral and cortical level. Congenitally deaf and hearing individuals performed two tactile tasks, the first requiring the discrimination of the temporal duration of touches and the second requiring the discrimination of their spatial length. Compared with hearing individuals, deaf individuals were impaired only in tactile temporal processing. To explore the neural substrate of this difference, we ran a TMS experiment. In deaf individuals, the auditory association cortex was involved in temporal and spatial tactile processing, with the same chronometry as the primary somatosensory cortex. In hearing participants, the involvement of auditory association cortex occurred at a later stage and selectively for temporal discrimination. The different chronometry in the recruitment of the auditory cortex in deaf individuals correlated with the tactile temporal impairment. Thus, early hearing experience seems to be crucial to develop an efficient temporal processing across modalities, suggesting that plasticity does not necessarily result in behavioral compensation.

Morphometric Differences in the Heschl's Gyrus of Hearing Impaired and Normal Hearing Infants

This study investigates the morphometry of Heschl's gyrus and its included primary auditory cortex (PAC) in hearing impaired (HI) and normal hearing (NH) infants. Fourty-two infants, age 8-19 months, with NH (n = 26) or hearing impairment (n = 16) were studied using high-resolution 3D magnetic resonance imaging. Gray matter (GM) and white matter (WM) volumes were obtained using software for automatic brain imaging segmentation to estimate the volume of each tissue within manually defined regions for the anterior portion of Heschl's gyrus (aHG) in each individual subject, transformed to an infant brain template space. Interactions among group (HI, NH), tissue type (GM, WM), and hemisphere (left, right) were examined using analysis of variance. Whole-brain voxel-based morphometry was utilized to explore volume differences between groups across the entire brain. The HI group showed increased GM and decreased WM in aHG compared with the NH group; likely effects of auditory deprivation. The HI group did not exhibit their typical L > R asymmetry pattern that the NH group showed. Increased GM in aHG in HI infants may represent abnormal cortical development in PAC as seen in animal models of sensory deprivation. Lower WM volume is consistent with studies with deaf adults.

Effect of auditory deprivation on binaural sensitivity in bilateral cochlear implant users.

Increasing numbers of cochlear implant (CI) users receive Implants in both ears in an effort to restore spatial hearing abilities. A known limitation of commercial CI devices is lack of synchrony to the signal fine timing cues arriving at the two ears. In addition to these hardware limitations, which may contribute in substantial ways to the gap in performance typically seen between bilateral CI users and normal-hearing people, there are considerable inter-subject differences in the type and history of hearing loss. We use a research processor which enables inter-aurally coordinated pulsatile stimulation of selected pairs of electrodes in the right and left ears. This project is concerned with the effects of the age at onset of deafness, and place of stimulation, on binaural sensitivity. Thresholds for discrimination of inter-aural time difference (ITD) and inter-aural level difference(ILD) and pointer-identification for perceived intracranial position were measured. Prelingually deafened subjects had no sensitivity to ITD but retained ILD sensitivity. People with childhood- or adult-onset of deafness retained sensitivity to both ITD and ILD, some within normal-hearing level of performance on some conditions. The role of auditory deprivation in the emergence and preservation of binaural sensitivity will be discussed. [Work supported by NIH-NIDCD.]

The influence of a sensitive period for auditory-visual integration in children with cochlear implants

Children who experience long periods of auditory deprivation are susceptible to large-scale reorganization of auditory cortical areas responsible for the perception of speech and language. One consequence of this reorganization is that integration of combined auditory and visual information may be altered after hearing is restored with a cochlear implant. Our goal was to investigate the effects of reorganization in a task that examines performance during multisensory integration. Reaction times to the detection of basic auditory (A), visual (V), and combined auditory-visual (AV) stimuli were examined in a group of normally hearing children, and in two groups of cochlear implanted children: (1) early implanted children in whom cortical auditory evoked potentials (CAEPs) fell within normal developmental limits, and (2) late implanted children in whom CAEPs were outside of normal developmental limits. Miller's test of the race model inequality was performed for each group in order to examine the effects of auditory deprivation on multisensory integration abilities after implantation. Results revealed a significant violation of the race model inequality in the normally hearing and early implanted children, but not in the group of late implanted children. These results suggest that coactivation to multi-modal sensory input cannot explain the decreased reaction times to multi-modal input in late implanted children. These results are discussed in regards to current models for coactivation to redundant sensory information.

Attention to speech sounds in normal-hearing and deaf children with cochlear implants.

Cochlear implantation (CI) is a treatment for severe-to-profound hearing loss in congenitally deaf children. Although there is very little variability in auditory thresholds among CI recipients, there is a large amount of variability in language outcomes. One possible source of variability in language outcomes is individual differences in attention and cognitive processes, which may be affected by early auditory deprivation. The effect of auditory deprivation on attention to auditory input was investigated by comparing attention to speech sounds in 23 young deaf children with CIs and 23 normal-hearing age-match controls. The deaf children received their CIs between 6 and 23 months and were tested several times during the first 1.5 years after implantation. Participants were seated on their caregiver’s lap in front of a TV monitor. On each trial, they were presented with a checkerboard pattern and either silence or a repeating speech sound. Normal-hearing children looked longer at the checkerboard during the sound trials at the youngest ages whereas CI children were delayed in showing a preference for the sound trials. Moreover, performance on this task correlated with language outcome measures taken two years later, suggesting that attention to speech sounds after implantation is predictive of later language development.

Treatment of Tinnitus With a Customized, Dynamic Acoustic Neural Stimulus: Underlying Principles and Clinical Efficacy

Tinnitus has been challenging to treat with consistently positive results. The Neuromonics Tinnitus Treatment is a newly available approach to the treatment of clinically significant, problematic tinnitus (and reduced sound tolerance) that was developed with the intention of simultaneously addressing the auditory, attentional, and emotional processes underlying the condition. It uses a prescribed acoustic stimulus, customized for each patient's individual audiometric profile, which provides a broad frequency stimulus to address the effects of auditory deprivation, promotes relief and relaxation with the intention of reducing engagement of the limbic system/amygdala and autonomic nervous system, and applies the principles of systematic desensitization to address the attentional processes. This article describes the underlying principles behind this approach. It also summarizes evidence for clinical efficacy from controlled clinical studies and from a private practice clinical setting, where it has been shown to provide consistently positive outcomes for patients meeting suitability criteria.