Hearing Control Group Research Articles

Sensitivity to interaural time differences and localization accuracy in cochlear implant users with combined electric-acoustic stimulation.

ObjectivesIn this study, localization accuracy and sensitivity to acoustic interaural time differences (ITDs) in subjects using cochlear implants with combined electric-acoustic stimulation (EAS) were assessed and compared with the results of a normal hearing control group.MethodsEight CI users with EAS (2 bilaterally implanted, 6 unilaterally implanted) and symmetric binaural acoustic hearing and 24 normal hearing subjects participated in the study. The first experiment determined mean localization error (MLE) for different angles of sound incidence between ± 60° (frontal and dorsal presentation). The stimuli were either low-pass, high-pass or broadband noise bursts. In a second experiment, just noticeable differences (JND) of ITDs were measured for pure tones of 125 Hz, 250 Hz and 500 Hz (headphone presentation).ResultsExperiment 1: MLE of EAS subjects was 8.5°, 14.3° and 14.7°, (low-, high-pass and broadband stimuli respectively). In the control group, MLE was 1.8° (broadband stimuli). In the differentiation between sound incidence from front and back, EAS subjects performed on chance level. Experiment 2: The JND-ITDs were 88.7 μs for 125 Hz, 48.8 μs for 250 Hz and 52.9 μs for 500 Hz (EAS subjects). Compared to the control group, JND-ITD for 125 Hz was on the same level of performance. No statistically significant correlation was found between MLE and JND-ITD in the EAS cohort.ConclusionsNear to normal ITD sensitivity in the lower frequency acoustic hearing was demonstrated in a cohort of EAS users. However, in an acoustic localization task, the majority of the subjects did not reached the level of accuracy of normal hearing. Presumably, signal processing time delay differences between devices used on both sides are deteriorating the transfer of precise binaural timing cues.

Effect of Hearing Aid Acclimatization on Speech-in-Noise Perception and Its Relationship With Changes in Auditory Long Latency Responses.

Objective The study attempted to track speech-in-noise perception and auditory long latency responses (ALLRs) over a period of hearing aid use in naïve hearing aid users. The primary aim was to investigate the relationship of change in speech-in-noise perception with the change in ALLRs. Method Thirty adults with mild-to-moderate sensorineural hearing loss (clinical group) and 17 adults with normal hearing (control group) in the age range of 23-60 years participated in the study. Syllable identification in noise (SIN) and ALLRs in noise were measured three times (three sessions) over a period of 2 months of hearing aid use. Results Results showed a significant increase in SIN and a decrease in the latency of ALLRs in the later sessions compared to the baseline session in the clinical group. However, the changes seen across the three sessions in the control group were not statistically significant. The magnitude of change in ALLRs seen in the clinical group did not significantly correlate with the change in SIN scores seen in them. Conclusions The study provides evidence for improvements in speech perception in noise and in processing time of auditory cortical areas with hearing aid acclimatization. However, it is important to note that the improvement in ALLRs does not assure improvement in speech perception in noise.

Increased Right Posterior STS Recruitment Without Enhanced Directional-Tuning During Tactile Motion Processing in Early Deaf Individuals.

Upon early sensory deprivation, the remaining modalities often exhibit cross-modal reorganization, such as primary auditory cortex (PAC) recruitment for visual motion processing in early deafness (ED). Previous studies of compensatory plasticity in ED individuals have given less attention to tactile motion processing. In the current study, we aimed to examine the effects of early auditory deprivation on tactile motion processing. We simulated four directions of tactile motion on each participant’s right index finger and characterized their tactile motion responses and directional-tuning profiles using population receptive field analysis. Similar tactile motion responses were found within primary (SI) and secondary (SII) somatosensory cortices between ED and hearing control groups, whereas ED individuals showed a reduced proportion of voxels with directionally tuned responses in SI contralateral to stimulation. There were also significant but minimal responses to tactile motion within PAC for both groups. While early deaf individuals show significantly larger recruitment of right posterior superior temporal sulcus (pSTS) region upon tactile motion stimulation, there was no evidence of enhanced directional tuning. Greater recruitment of right pSTS region is consistent with prior studies reporting reorganization of multimodal areas due to sensory deprivation. The absence of increased directional tuning within the right pSTS region may suggest a more distributed population of neurons dedicated to processing tactile spatial information as a consequence of early auditory deprivation.

A Novel Bone Conduction Hearing System May Improve Memory Function in Children with Single Side Hearing loss: A Case-Control Study.

To evaluate the effects of an adhesive adapter prosthesis (AAP) on memory function in pediatric subjects with single side hearing loss (SSHL). Case-control study. 19 pediatric subjects with mild to moderate SSHL treated with AAP and 15 subjects with normal hearing (control group) were included in this study. Working and short-term memory functions were tested in all subjects, in silence and noise conditions. In SSHL subjects, tests were performed before the AAP was applied (T0) and at 1-month (T1) follow-up. The control group was tested once. AAP significantly improved working memory function in noise as measured at T1 (p<0.01) compared with T0, but T1 scores in children with SSHL remained significantly different from the ones of the control group (p<0.01). AAP also significantly improved short- term memory function test scores at T1 compared with T0 (p<0.01), but despite being in the normal range for the subjects' age, the scores remained significantly different from those of the control group (p<0.01). In pediatric subjects with mild, moderate, and moderate-severe SSHL, restoration of bilateral hearing through AAP improved short-term memory function and working memory function in noise, as measured at 1 month follow-up; however, AAP did not seem to lead to a full restoration of such functions as measured by a comparison with healthy controls. Further studies with longer follow-ups might help elucidate whether AAP can elicit further improvements in memory functions.

Effect of Hearing Impairment on Behavior and Communication of Children in Schools and Special Education Centers in Mosul City

Objectives: To identify the effect of hearing impairment on children behavior in daily activities and communication with peers and problems facing teachers of HI children in Iraqi environment. Methods : the strength and difficult questionnaire (SDQ) was used to measure the behavioral, and peer problems questionnaire to measure communication disorders of children with HI based on parents and teachers in (209) children (123) HI and (86) normal hearing control group. Results: on parent teacher questionnaire significantly higher behavioral problems for HI children compared with control group (p-value 0.043&lt; alpha value 0.05) and (chi-square 7.321) so increase the emotional problems (p-value 0.035)and peer problems (0.026) of HI children its highly significant found of behavioral problems, so 65% of hearing impaired children had communication problems with others and environment. The teachers facing many problems when deals with HI but the most common one difficult when communicate with them because the limited capabilities available and modern educational methods for teaching the HI children. Conclusions: The majority of hearing impaired children have congenital cause for their hearing loss. Behavior problems appear more common in children with hearing loss and communication problems. The vast majority of teachers agree that there are problems facing students with hearing impairment, and these difficulties need to be dealt with the benefit of their children and the community as a whole.

ОБСТЕЖЕННЯ СЕНСОРНОДЕПРИВОВАНИХ ПІДЛІТКІВ ЗА МЕТОДИКОЮ «ДІАГНОСТ-1М»

Introduction . The study of the effect of sensory deprivation on the sensorimotor response by adolescents 14-17 years of age with visual and hearing impairment is considered in the article. People with visual and hearing impairments have a significant number amonge children and adolescents with developmental disabilities in Ukraine. Sensory deprivation is a long-term deprivation of a person's sensory impressions. The need for feelings and affective experiences is actualized in the context of sensory deprivation. This is realized in the form of sensory and emotional hunger. Imagination processes are activated in response to insufficiency of afferents. This has a certain effect on figurative memory. Bright, eidetic ideas emerge that are projected from the outside. These occurrences are evaluated as protective reactions (compensatory). Scientists have begun to study the sensorimotor reactions of humans to understand the mechanisms of integrative activity of the brain, the complex dynamic organization of its various structures. Scientists have actively studied the impact of sensory deprivation on the psychophysiological state of human over the last decade, but there is still no clear picture of the physical and mental state for a sensory deprived teenager. The objective is to obtain and analyze new scientific data about the specificity of the influence of auditory and visual sensory deprivation on the sensorimotor reaction among teenagers aged 14–17. Methods . The study was conducted among 151 teenagers aged 14-17 years . They were divided into three groups: control (healthy students), group of hearing impaired children and group of children with visual impairments. Each group was divided into two subgroups by age: 1st subgroup - students 14-15 years; 2nd subgroup - 16-17 years. Sensory motor reactions were investigated using the «Diagnost-1M» computer technique. This technique is widely tested and has been used quite successfully in many research and educational institutions to diagnose the properties of various psychophysiological functions. It is developed in the Laboratory of Physiology of Higher Nervous Activity of Human Institute of the Institute of Physiology. OO Bogomolets, NAS of Ukraine (Kyiv) by Professors M.V. Makarenko and V.S. Lyzohub. Results . We investigated sensory-motor responses in adolescents with auditory sensory deprivation to sound stimuli. Three sounds with different tones were used: low, medium and high. Statistical analysis of the obtained data of latent periods of different sensorimotor responses in the experimental and control groups showed that, as a whole, the level of adolescents with visual sensory deprivation of both age subgroups was much higher than that of students with hearing impairment and control group. The qualitative distribution of the surveyed children according to the levels of latent periods of simple auditory-motor reaction showed that in the group of sensory deprived persons the highest number (60%) of persons with a very long latency period (low tone) and in the control group - 37% (middle tone). Significant changes are not observed with using sound stimuli for adolescents of the control group, unlike the experimental group. Improvement indicators with age have been identified. The indicators are better for the surveyed of all three groups aged 16-17 years, unlike adolescents 14-15 years. Conclusion. During the studying of the sensorimotor reaction to the stress of varying degrees of difficulty, it was found that that latent periods of differing by the complexity visual-motor responses among children with visual impairment to the sounds are much better than among children from the control group and children with auditory sensory deprivation . This is due to the high level of spatial hearing development and well-developed auditory memory. Sensomotor response rates were better for hearing impaired students on low-pitched sound stimuli than on high- and medium-high stimuli. It can be concluded that with age the indicators of sensorimotor response to loads of varying degrees of complexity improve. Assumptions can be made on the basis of the analysis of the results of the study of sensorimotor response that in the group of students with visual sensory deprivation there is a process of compensating the lost function of the visual analyzer due to auditory.

Mortality and Cause of Death in Hearing Loss Participants: A Longitudinal Follow-up Study Using a National Sample Cohort.

The purpose of the present study was to estimate the risk of mortality in hearing loss subjects in accordance with the cause of death. A longitudinal follow up study. Data from the Korean National Health Insurance Service-National Sample Cohort were collected from a period between 2002 and 2013. The 4,606 severe and 1,007 profound hearing loss participants with 40 or more years old were 1:4 matched with control participants, respectively, for age, sex, income, and region of residence. The causes of death were grouped into 12 classifications. The ratio of mortality was compared between the hearing loss and control group using a χ test or Fisher's exact test. In a Cox-proportional hazard model, age, sex, income, region of residence, and past medical histories were considered confounders. The severe and profound hearing loss groups showed 4.07 (95% CI = 3.71-4.46, p < 0.001) and 4.22 times (95% CI = 3.52-5.05, p < 0.001) higher mortality ratios in the adjusted models, respectively. Both the severe and profound hearing loss groups showed higher mortality by infection, neoplasm, trauma, and metabolic, mental, circulatory, respiratory, and digestive diseases than control groups (p < 0.05). Among various causes of death, death by trauma revealed the highest odds ratios in both the severe and profound hearing loss groups. Hearing loss was associated with a significant increase in mortality.

Development and validation of the protocol for the evaluation of voice in patients with hearing impairment (PEV-SHI)

IntroductionThe voice of individuals with hearing impairment has been widely described, and can be compromised in all levels of the phonatory system. ObjectiveTo develop and validate an instrument for evaluating the voice of this population. MethodsThe instrument underwent the validation steps suggested by the Scientific Advisory Committee of the Medical Outcomes Trust. The study sample consisted of seventy-eight Brazilian people with cochlear implants (experimental group) and 78 individuals with normal hearing (control group), divided in groups by age range — children from 3 to 5 years; children from 6 to 10 years and adults from 18 to 46 years. The study sample participated in a voice recording of the sustained vowel /a/, connected speech and spontaneous conversation, in which three voice specialists rated using the proposed instrument. It consists of visual-analog scales of suprasegmental aspects, respiratory-phonatory coordination, resonance, phonation, additional parameters and general vocal perception. ResultsEvaluation by an expert committee and a pilot test established content validity. Reliability measures showed excellent test-retest reproducibility for the majority of the parameters. Analysis with the ROC curve showed that perceptual evaluation with the sustained vowel did not strongly differentiate individuals with cochlear implants from those with normal hearing, and the parameter “speech rate” did not differentiate the groups at all. For the connected speech and spontaneous conversation, the majority of the parameters differentiated the experimental group from the control group with an area under the curve ≥0.7. The cutoff values with maximum specificity and sensitivity were 30.5 for mild, 49.0 for moderate and 69.5 for intense deviation. ConclusionsThe protocol for the evaluation of voice in subjects with hearing impairment, PEV-SHI, is a reliable and useful tool for assessing the particularities of the voice of individuals with hearing impairment treated with cochlear implants and can be used in research and clinical settings to standardize evaluation and facilitate information exchange among services.

Comparison of Otoacoustic Emissions in Asymptomatic Diabetes Mellitus and Normal Hearing Control Groups

Background: Diabetes mellitus (DM) is a chronic metabolic disorder. Previous studies reported the hearing impairment of diabetes patients as a progressive bilateral symmetrical sensorineural hearing loss (SNHL) of gradual onset which predominantly affected the higher frequencies, and found that diabetic patients had unsatisfactory hearing thresholds than nondiabetics in the same age group. For the use of evoked otoacoustic emissions (EOAEs) as a clinical test of hearing, EOAEs are sound which can be recorded in the outer ear canal and give objective information about preneural, mechanical elements of the cochlear function.&#x0D; Objective: To compare the otoacoustic emissions of asymptomatic DM patients with a normal hearing control group.&#x0D; Methods: All subjects received a routine audiologic evaluation which consisted of pure-tone air-bone conduction tests, tympanograms, and stapedius acoustic reflex tests. OAEs were measured in 30 asymptomatic diabetic patients with a mean age of 55.73 years and an age-matched 30 subjects normal hearing control group with a mean age of 50.87 years.&#x0D; Results: The pure-tone thresholds at 3, 4, 6, and 8 kHz; transient-evoked otoacoustic emissions (TEOAEs) amplitudes at 1, 1.5, 2, and 3 kHz; and the distortion product otoacoustic emissions (DPOAEs) amplitudes at 1, 1.5, 2, 3, 4, and 6 kHz were significantly different (P &lt; .05) between the asymptomatic and control groups.&#x0D; Conclusions: This study suggested that diabetic patients had a significant hearing impairment. SNHL is gradually progressive and is a common condition in DM patients and their thresholds for hearing are higher at higher frequencies.

Can subtitles for the deaf and hard-of-hearing convey the emotions of film music? A reception study

ABSTRACTThe present paper describes a reception study into subtitling music in subtitles for the d/Deaf and hard-of-hearing. The study makes use of a database of film fragments that were selected and tested for eliciting a specific emotion. The research involves two highly emotional clips from the database as well as one control clip. The three excerpts were shown to a control group of 26 hearing people. Then, three versions of subtitles were added to each clip – one with music description, another with the composition title and the name of the performer, and another one with no information on the music. Subsequently, the fragments were shown to a test group of 60 d/Deaf and hard-of-hearing viewers divided into three groups. The participants reported on the emotions they felt by filling a Differential Emotions Scale questionnaire. For every emotion the clips were supposed to elicit, the results for each subtitling method are very similar to each other, suggesting that either method of subtitling music is equally effective in an emotional scene. Moreover, the emotion intensity the d/Deaf felt is also very close to the intensity experienced by the hard-of-hearing and the hearing control group.

Deaf and Hard of Hearing Students' Understanding of Causal and Adversative Connectives in Sentence Reading.

Deaf and hard of hearing (DHH) students tend to experience delayed development of grammatical skills in written language. However, much remains unknown about the mechanism behind this phenomenon. In the present study, the researchers used a self-paced moving-window reading task to investigate DHH students' understanding of causal and adversative connectives in Chinese. The students were similar to a hearing control group in their comprehension of the relationship between the clauses in a causal sentence. However, the DHH students were more likely than their hearing peers to find it harder to understand adversative connectives than causal connectives. More studies are needed to reveal how DHH students deal with other syntactic structures that are particularly difficult for them to learn. Educators should pay close attention to creating learning environments in which DHH students can acquire those syntactic structures in the process of using language.

Spelling in Children With Cochlear Implants: Evidence of Underlying Processing Differences.

This study compared the spelling skills and sub-skills of young children with cochlear implants (CIs) who use spoken language only (n = 14) with those of a same-aged typically hearing (TH) control group (n = 30). Spelling accuracy was assessed using irregular and nonsense word stimuli. Error and regression analyses were conducted to provide insight into the phonological and orthographic spelling strategies used by each group. Results indicated that children with CIs were as accurate as the TH group. However, misspellings made by the CI group were less phonologically plausible, and while nonword spelling accuracy was related to letter-sound knowledge for the TH group, the same relationship was non-significant for the CI group. Hence, despite demonstrating a similar degree of overall spelling success to TH children, children with CIs appeared to apply phonics skills less effectively.

Comparing physical activity and sedentary behavior levels between deaf and hearing adolescents

BackgroundDeaf adolescents may engage in less physical activity (PA) and longer sedentary time than their hearing peers. Yet, literature comparing PA levels and sedentary time between deaf and hearing control groups, as well as studies examining predictors of PA among deaf adolescents, are lacking. ObjectiveThis cross-sectional survey aimed to compare PA levels and sedentary time between the two groups and examine predictors (i.e., gender and social inclusion) of PA participation among deaf adolescents. MethodsParticipants were 98 deaf and 99 hearing adolescents, who completed the survey measuring the variables of interest. ResultsDeaf adolescents had a higher level of sedentary behavior as well as lower levels of light PA, moderate-to-vigorous PA, and total metabolic equivalent task (MET) than the hearing group. Only a small proportion of participants (deaf: 4%; hearing: 24%) met the World Health Organization's PA recommendation. Gender was found to negatively predict total MET among deaf, while social inclusion was a positive predictor. ConclusionsDeaf adolescents may have restricted PA participation. Measures should be used to promote social inclusion for increasing PA levels of this population.

Anatomical and Functional MRI Changes after One Year of Auditory Rehabilitation with Hearing Aids.

Hearing aids (HAs) are an effective strategy for auditory rehabilitation in patients with peripheral hearing deficits. Yet, the neurophysiological mechanisms behind HA use are still unclear. Thus far, most studies have focused on changes in the auditory system, although it is expected that hearing deficits affect a number of cognitive systems, notably speech. In the present study, we used audiometric evaluations in 14 patients with bilateral hearing loss before and after one year of continuous HA use and functional magnetic resonance imaging (fMRI) and cortical thickness analysis in 12 and 10 of them compared with a normal hearing control group. Prior to HA fitting, fMRI activity was found reduced in the auditory and language systems and increased in visual and frontal areas, expanding to multimodal integration cortices, such as the superior temporal gyrus, intraparietal sulcus, and insula. One year after rehabilitation with HA, significant audiometric improvement was observed, especially in free-field Speech Reception Threshold (SRT) test and functional gain, a measure of HA efficiency. HA use increased fMRI activity in the auditory and language cortices and multimodal integration areas. Individual fMRI signal changes from all these areas were positively correlated with individual SRT changes. Before rehabilitation, cortical thickness was increased in parts of the prefrontal cortex, precuneus, fusiform gyrus, and middle temporal gyrus. It was reduced in the insula, supramarginal gyrus, medial temporal gyrus, occipital cortex, posterior cingulate cortex, and claustrum. After HA use, increased cortical thickness was observed in multimodal integration regions, particularly the very caudal end of the superior temporal sulcus, the angular gyrus, and the inferior parietal gyrus/superior temporal gyrus/insula. Our data provide the first evidence that one year of HA use is related to functional and anatomical brain changes, notably in auditory and language systems, extending to multimodal cortices.

Association of glutamate metabotropic receptor polymorphisms and sensorineural hearing loss in adults of different age groups

IntroductionSensorineural hearing loss is a common challenge all over the world, including a section of the young population. While there have been many published reports associating glutamate metabotropic receptor 7 with sensorineural hearing loss, there is no report, till date, about the association of glutamate metabotropic receptor 7 polymorphisms with sensorineural hearing loss at different ages. ObjectiveTo test the association between the single nucleotide polymorphisms rs11928865 and rs11920109 of the glutamate metabotropic receptor 7 with sensorineural hearing loss in adults of different age groups. MethodsA total of 1661 subjects were studied. The individuals aged between 30 and 50, and between 51 and 70 years with sensorineural hearing loss comprised group A and group B, respectively. Individuals aged between 30 and 50; and between 51 and 70 years without hearing loss comprised control groups C and D, respectively. The MassARRAY method was used to analyze the genotypes. ResultsThe difference in genotypes for the glutamate metabotropic receptor 7 rs11928865 single nucleotide polymorphism between patients in the groups B and D was statistically significant (p=0.018). The distribution frequencies of genotypes in patients that were aged between 30 and 50 years were not significantly different. The difference in genotypes for the rs11920109 single nucleotide polymorphism between the sensorineural hearing loss groups and control groups showed no statistical significance. ConclusionThe rs11928865 single nucleotide polymorphism was associated with the susceptibility to hearing loss in patients in group B but not with those in group A.

Auditory and language outcomes in children with unilateral hearing loss

ObjectivesChildren with unilateral hearing loss (UHL) are being diagnosed at younger ages because of newborn hearing screening. Historically, they have been considered at risk for difficulties in listening and language development. Little information is available on contemporary cohorts of children identified in the early months of life. We examined auditory and language acquisition outcomes in a contemporary cohort of early-identified children with UHL and compared their outcomes at preschool age with peers with mild bilateral loss and with normal hearing. DesignAs part of the Mild and Unilateral Hearing Loss in Children Study, we collected auditory and spoken language outcomes on children with unilateral, bilateral hearing loss and with normal hearing over a four-year period. This report provides a cross-sectional analysis of results at age 48 months. A total of 120 children (38 unilateral and 31 bilateral mild, 51 normal hearing) were enrolled in the study from 2010 to 2015. Children started the study at varying ages between 12 and 36 months of age and were followed until age 36–48 months. The median age of identification of hearing loss was 3.4 months (IQR: 2.0, 5.5) for unilateral and 3.6 months (IQR: 2.7, 5.9) for the mild bilateral group. Families completed an intake form at enrolment to provide baseline child and family-related characteristics. Data on amplification fitting and use were collected via parent questionnaires at each annual assessment interval. This study involved a range of auditory development and language measures. For this report, we focus on the end of follow-up results from two auditory development questionnaires and three standardized speech-language assessments. Assessments included in this report were completed at a median age of 47.8 months (IQR: 38.8, 48.5). Using ANOVA, we examined auditory and language outcomes in children with UHL and compared their scores to children with mild bilateral hearing loss and those with normal hearing. ResultsOn most measures, children with UHL performed poorer than those in the mild bilateral and normal hearing study groups. All children with hearing loss performed at lower levels compared to the normal hearing control group. However, mean standard scores for the normal hearing group in this study were above normative means for the language measures. In particular, children with UHL showed gaps compared to the normal hearing control group in functional auditory listening and in receptive and expressive language skills (three quarters of one standard deviation below) at age 48 months. Their performance in receptive vocabulary and speech production was not significantly different from that of their hearing peers. ConclusionsEven when identified in the first months of life, children with UHL show a tendency to lag behind their normal hearing peers in functional auditory listening and in receptive and expressive language development.

The Effects of Musical Experience and Hearing Loss on Solving an Audio-Based Gaming Task

We conducted an experiment using a purposefully designed audio-based game called the Music Puzzle with Japanese university students with different levels of hearing acuity and experience with music in order to determine the effects of these factors on solving such games. A group of hearing-impaired students (n = 12) was compared with two hearing control groups with the additional characteristic of having high (n = 12) or low (n = 12) engagement in musical activities. The game was played with three sound sets or modes; speech, music, and a mix of the two. The results showed that people with hearing loss had longer processing times for sounds when playing the game. Solving the game task in the speech mode was found particularly difficult for the group with hearing loss, and while they found the game difficult in general, they expressed a fondness for the game and a preference for music. Participants with less musical experience showed difficulties in playing the game with musical material. We were able to explain the impacts of hearing acuity and musical experience; furthermore, we can promote this kind of tool as a viable way to train hearing by focused listening to sound, particularly with music.

Changes in gray and white matter in subgroups within the tinnitus population

In this study, we investigated gray and white matter changes in subgroups within the larger tinnitus population related to differences in severity or duration of tinnitus symptoms. Tinnitus is the illusory perception of sound in the absence of an external source, most often experienced as a chronic condition. The psychological reaction to the sound constitutes the severity, or degree of discomfort experienced, and the duration refers to the time since onset of chronic tinnitus. We used voxel- and surface-based morphometry to investigate gray matter changes and diffusion tensor imaging (using fractional anisotropy, or FA, metrics) to assess changes in orientation of white matter tracts, using both whole brain and region of interest analyses. Whole brain analyses revealed decreased cortical thickness in the left parahippocampal gyrus in those with more severe tinnitus compared to a group with a milder reaction, and reduced gray matter volume in left anterior cingulate in those with mild tinnitus compared to a normal hearing control group without tinnitus. In the analysis based on FA, no significant differences were revealed between the subgroups or with respect to control groups in either whole brain or region of interest analyses. Our results suggest that these subgroups within the tinnitus population likely exhibit different anatomical alterations related to the disorder, which may explain the variable findings in the literature, particularly in terms of gray matter.

Early use of phonological codes in deaf readers: An ERP study

Previous studies suggest that deaf readers use phonological information of words when it is explicitly demanded by the task itself. However, whether phonological encoding is automatic remains controversial. The present experiment examined whether adult congenitally deaf readers show evidence of automatic use of phonological information during visual word recognition. In an ERP masked priming lexical decision experiment, deaf participants responded to target words preceded by a pseudohomophone (koral – CORAL) or an orthographic control prime (toral – CORAL). Responses were faster for the pseudohomophone than for the orthographic control condition. The N250 and N400 amplitudes were reduced for the pseudohomophone when compared to the orthographic control condition. Furthermore, the magnitude of both the behavioral and the ERP pseudohomophone effects in deaf readers was similar to that of a group of well-matched hearing controls. These findings reveal that phonological encoding is available to deaf readers from the early stages of visual word recognition. Finally, the pattern of correlations of phonological priming with reading ability suggested that the amount of sub-lexical use of phonological information could be a main contributor to reading ability for hearing but not for deaf readers.

Relationship between behavioral and electrophysiological hearing thresholds

Clinical applications for hearing thresholds obtained with electrophysiological measures are well established. Bush, Jones, and Shinn (2008) suggested that a diagnostic relationship exists between behavioral and auditory brainstem response (ABR) thresholds. They reported that subjects with MRI-confirmed vestibular schwannomas had differences greater than 30 dB when behavioral thresholds were compared to ABR using a 100 microsecond square wave (click) stimulus. However, there are little data available showing threshold relationships between behavioral and ABR thresholds for frequency specific stimuli. It is conceivable that a frequency specific stimulus may be more sensitive to schwannoma effects. Therefore, this project examined differences in hearing thresholds for normal hearing participants for two threshold methods (behavioral and ABR) and four stimuli: 250, 1000, and 4000 Hz tone bursts, and a 100 microsecond click. The same ABR instrument and stimuli were used for each method to obtain thresholds in twenty eight normal hearing adults in a repeated measures design. Results showed ABR thresholds to be significantly higher than behavioral. Thresholds varied significantly across stimuli for the ABR method but not the behavioral. Differences between methods were less than 30 dB for 93% of participants. These findings are consistent with Bush’s findings for a normal hearing control group.