Gender Categorization Is Abnormal in Cochlear Implant Users

In normal hearing (NH), the perception of the gender of a speaker is strongly affected by two anatomically related vocal characteristics: the fundamental frequency (F0), related to vocal pitch, and the vocal tract length (VTL), related to the height of the speaker. Previous studies on gender categorization in cochlear implant (CI) users found that performance was variable, with few CI users performing at the level of NH listeners. Data collected with recorded speech produced by multiple talkers suggests that CI users might rely more on F0 and less on VTL than NH listeners. However, because VTL cannot be accurately estimated from recordings, it is difficult to know how VTL contributes to gender categorization. In the present study, speech was synthesized to systematically vary F0, VTL, or both. Gender categorization was measured in CI users, as well as in NH participants listening to unprocessed (only synthesized) and vocoded (and synthesized) speech. Perceptual weights for F0 and VTL were derived from the performance data. With unprocessed speech, NH listeners used both cues (normalized perceptual weight: F0 = 3.76, VTL = 5.56). With vocoded speech, NH listeners still made use of both cues but less efficiently (normalized perceptual weight: F0 = 1.68, VTL = 0.63). CI users relied almost exclusively on F0 while VTL perception was profoundly impaired (normalized perceptual weight: F0 = 6.88, VTL = 0.59). As a result, CI users’ gender categorization was abnormal compared to NH listeners. Future CI signal processing should aim to improve the transmission of both F0 cues and VTL cues, as a normal gender categorization may benefit speech understanding in competing talker situations.     

Rapid Increase in Neural Conduction Time in the Adult Human Auditory Brainstem Following Sudden Unilateral Deafness

Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.     

Behavioural performance and self-report measures in children with unilateral hearing loss due to congenital aural atresia

ObjectiveTo explore the behavioural and functional performance of a group of children with conductive unilateral hearing loss (UHL) due to congenital aural atresia.MethodTwelve children aged 7 to 16 years (M_age 10.0, SD 3.1 years) formed the UHL group and 15 age-matched children (M_age 9.5, SD 3.6 years) with normal hearing formed the control group. Auditory skills were assessed using tests of sound localisation, spatial speech perception in noise, and self-ratings of auditory abilities (Listening Inventory for Education; LIFE and Speech, Spatial and Qualities of Hearing scale; SSQ).ResultsWhen speech was directed to the good ear, performance was poorer than for normal hearing controls. Sound localisation abilities were impaired in children with UHL. Children with UHL reported higher levels of difficulties in classroom settings compared to children with normal hearing, particularly for activities involving listening in noise and focused listening activities. Older children self-report and parents report difficulties for their children across all SSQ scales.ConclusionsChildren with UHL showed a wide range of auditory difficulties. As expected, speech recognition in noise differed from controls. Sound localisation abilities were variable; greater variability was seen for right ear hearing losses suggesting that some of these children may have developed compensatory mechanisms. Younger children identified listening difficulties for school situations where focussed auditory attention was needed. Older children and parents reported greatest difficulty for activities requiring perception of the direction, distance, and movement of sound. Higher levels of effort and inability to ignore sounds were reported as major difficulties.     

Asymmetry of temporal processing in listeners with normal hearing and unilaterally deaf subjects

OBJECTIVES: In general, auditory cortex on the left side of the brain is specialized for processing of acoustic stimuli with complex temporal structure including speech, and the right hemisphere is primary for spectral processing and favors tonal stimuli and music. This asymmetry in processing is further emphasized when hemisphere-favored stimuli are presented to the contralateral ear. The purpose of the first experiment is to further investigate the properties that dictate lateralized processing of auditory stimuli by ear and the relationship between auditory task and stimulus type. Next, it is not clear what compensation may exist for the loss of function of one ear and consequently, reduced access to functions primary performed in the opposite hemisphere, in the case of early unilateral profound hearing loss. The purpose of experiment 2 is to determine if any compensation for loss of function is seen in persons with early unilateral deafness. DESIGN: Experiment 1: Gap detection thresholds were determined in 30 right-handed listeners with normal hearing using wide-band noise markers (temporally complex), 400 and 4000 Hz pure tones presented individually to the left and right ears. Experiment 2: The same procedure was administered to listeners with early-onset, severe-to-profound unilateral deafness (seven left ear deaf and five right ear deaf) in the hearing ear alone. RESULTS: A significant right ear advantage was found for gap detection threshold using noise markers and a smaller left ear advantage was found for tonal stimuli. Listeners with unilateral deafness demonstrated that the hearing ear, left or right, performed in a manner similar to listeners with normal hearing. CONCLUSIONS: Results indicate that (1) gap marker, more than task, was the salient feature in determining laterality of processing in this experiment, (2) the two ears have distinct processing capacity based on stimulus type, and (3) compensation for loss is not apparent in persons with congenital unilateral deafness.     

Speech Perception in Noise with a Harmonic Complex Excited Vocoder

A cochlear implant (CI) presents band-pass-filtered acoustic envelope information by modulating current pulse train levels. Similarly, a vocoder presents envelope information by modulating an acoustic carrier. By studying how normal hearing (NH) listeners are able to understand degraded speech signals with a vocoder, the parameters that best simulate electric hearing and factors that might contribute to the NH-CI performance difference may be better understood. A vocoder with harmonic complex carriers (fundamental frequency, f₀ = 100 Hz) was used to study the effect of carrier phase dispersion on speech envelopes and intelligibility. The starting phases of the harmonic components were randomly dispersed to varying degrees prior to carrier filtering and modulation. NH listeners were tested on recognition of a closed set of vocoded words in background noise. Two sets of synthesis filters simulated different amounts of current spread in CIs. Results showed that the speech vocoded with carriers whose starting phases were maximally dispersed was the most intelligible. Superior speech understanding may have been a result of the flattening of the dispersed-phase carrier’s intrinsic temporal envelopes produced by the large number of interacting components in the high-frequency channels. Cross-correlogram analyses of auditory nerve model simulations confirmed that randomly dispersing the carrier’s component starting phases resulted in better neural envelope representation. However, neural metrics extracted from these analyses were not found to accurately predict speech recognition scores for all vocoded speech conditions. It is possible that central speech understanding mechanisms are insensitive to the envelope-fine structure dichotomy exploited by vocoders.     

Effects of age and hearing loss on gap detection and the precedence effect: narrow-band stimuli.

Deficits in temporal resolution and/or the precedence effect may underlie part of the speech understanding difficulties experienced by older listeners in degraded acoustic environments. In a previous investigation, R. Roberts and J. Lister (2004) identified a positive correlation between measures of temporal resolution and the precedence effect, specifically across-channel gap detection (as measured dichotically) and fusion. Across-channel gap detection may also be measured using frequency-disparate markers. Thus, the present investigation was designed to determine if the relation is specific to dichotic gap detection or may generalize to all types of across-channel gap detection. Gap-detection thresholds (GDTs) for fixed-frequency and frequency-disparate markers and lag-burst thresholds (LBTs) were measured for 3 groups of listeners: young with normal hearing sensitivity (YNH), older with normal hearing sensitivity (ONH), and older with sensorineural hearing loss (OIH). Also included were conditions of diotic and dichotic GDT. Largest GDTs were measured for the frequency-disparate markers, whereas largest LBTs were measured for the fixed-frequency markers. ONH and OIH listeners exhibited larger frequency-disparate and dichotic GDTs than YNH listeners. Listener age and hearing loss appeared to influence temporal resolution for frequency-disparate and dichotic stimuli, which is potentially important for the resolution of timing cues in speech. Age and hearing loss did not significantly influence fusion as measured by LBTs. Within each participant group, most GDTs and LBTs were positively, but not significantly, correlated. For all participants combined, across-channel GDTs and LBTs were positively and significantly correlated. This suggests that the 2 tasks may rely on a common across-channel temporal mechanism.     

Development of receptive vocabulary and verbal intelligence in Japanese children with unilateral hearing loss

ObjectiveIn the past, it was believed that unilateral hearing loss has a minimal impact on the speech and language development in children. However, several studies have suggested that some school-age children with unilateral hearing loss have learning impairments in language. In the present study, we first examined whether preschool-age children with unilateral severe-to-profound hearing loss (UHL) have delays in the development of receptive vocabulary and verbal intelligence. In the follow-up study, we tested the children again after school admission. The objective of the present study was to reveal the development of receptive vocabulary and verbal intelligence from preschool to school years in children with UHL.MethodsFifteen Japanese preschool-age children with UHL and a control group of 20 age-matched Japanese children with bilateral normal hearing (NH), who were examined because articulation disorder was suspected, were enrolled in this study. The development of receptive vocabulary and verbal intelligence was evaluated using the Picture Vocabulary Test-Revised (PVT-R) and the Wechsler Intelligence Scale, respectively. The present retrospective study was approved by the Committee for Medical Ethics of Tokushima University Hospital (#3801).ResultsThe scaled score (SS) of the PVT-R and verbal intelligence quotient (VIQ)/verbal comprehension index (VCI), but not performance intelligence quotient/perceptual reasoning index in children with UHL were significantly lower than those in the control children with NH at preschool-age. The SS of the PVT-R and VIQ/VCI in children with UHL significantly improved after school admission. In the subgroup analysis, the SS of the PVT-R in the lower receptive vocabulary group of children with UHL at preschool-age was significantly increased after school admission, but the SS in the normal and higher receptive vocabulary group of children with UHL at preschool-age were still around the standardized mean of SS after school admission.ConclusionThese findings suggest that the development of receptive vocabulary and verbal intelligence was delayed in preschool-age children with UHL and that most of them caught up to exhibit normal language ability after school admission.     

Evaluation of the preliminary auditory profile test battery in an international multi-centre study

Abstract

Objective: This paper describes the composition and international multi-centre evaluation of a battery of tests termed the preliminary auditory profile. It includes measures of loudness perception, listening effort, speech perception, spectral and temporal resolution, spatial hearing, self-reported disability and handicap, and cognition. Clinical applicability and comparability across different centres are investigated. Design: Headphone tests were conducted in five centres divided over four countries. Effects of test-retest, ear, and centre were investigated. Results for normally-hearing (NH) and hearing-impaired (HI) listeners are presented. Study sample: Thirty NH listeners aged 19–39 years, and 72 HI listeners aged 22–91 years with a broad range of hearing losses were included. Results: Test-retest reliability was generally good and there were very few right/left ear effects. Results of all tests were comparable across centres for NH listeners after baseline correction to account for necessary differences between test materials. For HI listeners, results were comparable across centres for the language-independent tests. Conclusions: The auditory profile forms a clinical test battery that is applicable in four different languages. Even after baseline correction, differences between test materials have to be taken into account when interpreting results of language-dependent tests in HI listeners.     

Random Gap Detection Test and Random Gap Detection Test-Expanded results in children with auditory neuropathy

Objectives

In auditory neuropathy (AN) children with hearing aids (HAs) or cochlear implant (CI), the speech perception improvement may not be in a significant degree. These children may perform speech perception after a few repeats. This condition may show that these children had difficulties in receiving and processing speech sounds. If the children with AN cannot distinguish the heard tones one or two in Random Gap Detection Test (RGDT), their benefit performances between hearing aids or CI may not be significant. It is thought that the answer of this question is closely related with unique auditory processing performance of each child. The aim of the study is to investigate the RGDT and RGDT-Expanded (RGDT-EXP) performance of five children with AN.

Methods

In this study, RGDT was applied to five children with auditory neuropathy between ages of 7 and 13 years (study group) (3 male, 2 female). As a control group, RGDT was applied to 10 normal hearing children who had not auditory processing problem between ages of 7 and 16 years (5 male, 5 female). In the first test, all children were applied to RGDT and RGDT-EXP. Each child responded whether he/she heard one or two tones. Their responses were taken as verbally and/or hold up one finger or two fingers. In the second test, they were applied speech discrimination test in quiet environment and in noise. Gap detection thresholds (GDTs) were detected at 500-4000 Hz; and composite GDTs (CGDTs) were found for the study and control groups. GDT/CGDT >20 ms was considered as abnormal for temporal processing disorder.

Results

Any of the children with AN who has no HAs; with HAs; and CI, could not be able to perform RGDT. Therefore the RGDT-EXP was applied in this group. In the study group, GDTs was all over 50 ms at 500-4000 Hz; and CGDTs were all over 50 ms for all children included into the study group with AN. In control group, except child 9 (GDTs were 25 ms at 3000 and 4000 Hz); and child 10 (GDT was 25 ms at 500 Hz); GDTs were all in normal limits for 500-4000 Hz for all children included into the study as control group. CGDTs were all in normal limits for the control group, except child 9 (CGDTs were 22.50, slightly higher than normal limits). In the study group with AN, mean of the GDTs was all over the normal limits; and in control group, mean of GDTs were all in normal limits. The difference between the mean GDTs of the study group was significantly higher than the control groups at all frequencies of 500-4000. In AN group, CGDT (97.5 ± 9.57 ms) was significantly higher than that of the control group (10.35 ± 0.65 ms).

Conclusion

We concluded that these results may only not be explained by auditory processing performance or temporal aspects of audition of each child. Their gap detection was much worse for short duration stimuli than for longer duration stimuli. The present study showed that temporal processing, auditory timing and gap detection skills of the children with AN were found as delayed in advanced degree. These findings may indicate that the AN children cannot perform temporal asynchrony. Our results may help to understand why the children with AN cannot manage the speech perception; and why they understand the speech after a few repeats.     

Correction of the peripheral spatiotemporal response pattern: a potential new signal-processing strategy.

The purpose of this paper is to introduce a new signal-processing strategy, spatiotemporal pattern correction (SPC), that is based on our knowledge of the level-dependent temporal response properties of auditory nerve fibers in normal and impaired ears. In normal-hearing listeners, tuning is sharp for low-level inputs and broadens as input level increases. When peripheral filters change their shape with input level, the phase properties of the filters and the latency of the filter's response also change. However, in listeners with hearing loss, tuning is broad for both low- and high-level inputs. Thus, there is little change in the phase properties of the filters for different input levels. The SPC strategy manipulates the temporal aspects of different frequency channels of sounds in an attempt to "correct" for this abnormal spatiotemporal response pattern of the impaired ear. Quality judgments and intelligibility measures of speech processed at various SPC strengths were obtained from a small group of normal-hearing listeners and listeners with hearing loss. In general, listeners with hearing loss preferred sentences with some degree of SPC processing, whereas normal-hearing listeners preferred unprocessed sentences. Benefit from SPC on the nonsense syllable test varied greatly across phonemes and listeners. A more comprehensive study of listeners with different degrees and configurations of hearing loss is needed to determine the amount of SPC benefit.     

PET imaging of cochlear-implant and normal-hearing subjects listening to speech and nonspeech.

Functional neuroimaging with positron emission tomography (PET) was used to compare the brain activation patterns of normal-hearing (NH) with postlingually deaf, cochlear-implant (CI) subjects listening to speech and nonspeech signals. The speech stimuli were derived from test batteries for assessing speech-perception performance of hearing-impaired subjects with different sensory aids. Subjects were scanned while passively listening to monaural (right ear) stimuli in five conditions: Silent Baseline, Word, Sentence, Time-reversed Sentence, and Multitalker Babble. Both groups showed bilateral activation in superior and middle temporal gyri to speech and backward speech. However, group differences were observed in the Sentence compared to Silence condition. CI subjects showed more activated foci in right temporal regions, where lateralized mechanisms for prosodic (pitch) processing have been well established; NH subjects showed a focus in the left inferior frontal gyrus (Brodmann's area 47), where semantic processing has been implicated. Multitalker Babble activated auditory temporal regions in the CI group only. Whereas NH listeners probably habituated to this multitalker babble, the CI listeners may be using a perceptual strategy that emphasizes 'coarse' coding to perceive this stimulus globally as speechlike. The group differences provide the first neuroimaging evidence suggesting that postlingually deaf CI and NH subjects may engage differing perceptual processing strategies under certain speech conditions.     

儿童单侧听神经病附三例分析

目的 探讨儿童单侧听神经病的听力学特征。方法 对3例单侧听神经病患儿进行纯音听阈(PTT)、声反射(AR)、听性脑干反应(ABR)和畸变产物耳声发射(DPOAE)检查，并对其结果进行综合分析。结果 3例患儿的PTT均呈1侧耳听力正常，另1侧耳听力丧失。健耳的同侧和交叉AR能引出，患耳的同侧和交叉AR未能引出。健耳的ABR各波潜伏期正常，患耳的ABR各波未能引出。双耳DPOAE各频率反应幅值正常。结论：DPOAE正常或基本正常，PTT、AR和ABR异常是听神经病的重要特征。单侧听神经病的听力学特征与双侧听神经病基本一致。对儿童表现为单侧感音神经性聋者宜进行系统的听力学检查，以期作出正确的诊断。     

Spatial hearing of normally hearing and cochlear implanted children

Objective

Spatial hearing uses both monaural and binaural mechanisms that require sensitive hearing for normal function. Deaf children using either bilateral (BCI) or unilateral (UCI) cochlear implants would thus be expected to have poorer spatial hearing than normally hearing (NH) children. However, the relationship between spatial hearing in these various listener groups has not previously been extensively tested under ecologically valid conditions using a homogeneous group of children who are UCI users. We predicted that NH listeners would outperform BCI listeners who would, in turn, outperform UCI listeners.

Methods

We tested two methods of spatial hearing to provide norms for NH and UCI using children and preliminary data for BCI users. NH children (n = 40) were age matched (6-15 years) to UCI (n = 12) and BCI (n = 6) listeners. Testing used a horizontal ring of loudspeakers within a booth in a hospital outpatient clinic. In a ‘lateral release’ task, single nouns were presented frontally, and masking noises were presented frontally, or 90° left or right. In a ‘localization’ task, allowing head movements, nouns were presented from loudspeakers separated by 30°, 60° or 120° about the midline.

Results

Normally hearing children improved with age in speech detection in noise, but not in quiet or in lateral release. Implant users performed more poorly on all tasks. For frontal signals and noise, UCI and BCI listeners did not differ. For lateral noise, BCI listeners performed better on both sides (within ∼2 dB of NH), whereas UCI listeners benefited only when the noise was opposite the unimplanted ear. Both the BCI and, surprisingly, the UCI listeners performed better than chance at all loudspeaker separations on the ecologically valid, localization task. However, the BCI listeners performed about twice as well and, in two cases, approached the performance of NH children.

Conclusion

Children using either UCI or BCI have useful spatial hearing. BCI listeners gain benefits on both sides, and localize better, but not as well as NH listeners.     

Temporal summation in hearing-impaired listeners

A study was conducted to explore variations in auditory temporal summation in listeners with normal hearing, and impairment due to otosclerosis, sensori-neural hearing loss and acoustic neuroma. Using a two-interval forced-choice procedure the detection threshold was measured for one-third octave noise bands centered at either 1000 or 4000 Hz, in combination with eight signal durations (2.5, 5, 10, 20, 40, 80, 160, and 640 ms). The results indicated that for normal listeners: (1) the slope of the function relating the detection threshold and the signal duration varied inversely with the frequency tested, and (2) the variability in the detection threshold was greater for 4000 Hz than for 1000 Hz. A comparison of performance across groups showed that the magnitude of the slope of the temporal integration function decreased as the site of lesion moved from middle ear to eighth nerve. For listeners with normal hearing and those with otosclerosis, temporal integration appeared to be incomplete at 640 ms.     

Characteristics of children with unilateral hearing loss

Objective: The purpose of this study was to describe the clinical characteristics of children with unilateral hearing loss (UHL), examine deterioration in hearing, and explore amplification decisions. Design: Population-based data were collected prospectively from time of diagnosis. Serial audiograms and amplification details were retrospectively extracted from clinical charts to document the trajectory and management of hearing loss. Sample: The study included all children identified with UHL in one region of Canada over a 13-year period (2003–2015) after implementation of universal newborn hearing screening. Results: Of 537 children with permanent hearing loss, 20.1% (108) presented with UHL at diagnosis. They were identified at a median age of 13.9 months (IQR: 2.8, 49.0). Children with congenital loss were identified at 2.8 months (IQR: 2.0, 3.6) and made up 47.2% (n?=?51), reflecting that a substantial portion had late-onset, acquired or late-identified loss. A total of 42.4% (n?=?39) showed deterioration in hearing, including 16 (17.4%) who developed bilateral loss. By study end, 73.1% (79/108) of children had received amplification recommendations. Conclusions: Up to 20% of children with permanent HL are first diagnosed with UHL. About 40% are at risk for deterioration in hearing either in the impaired ear and/or in the normal hearing ear.     

BAHA in children and adolescents with unilateral or bilateral conductive hearing loss: a study of outcome

OBJECTIVES: Bilateral BAHAs in adults with bilateral hearing loss (BHL) have proven to be superior to unilateral fitting, in both audiologically measurements and in overall patient satisfaction. There have been no similar studies in children. Furthermore, a recent meta-analysis of children with unilateral hearing loss (UHL) has shown numerous negative consequences. The objectives of the study were to investigate whether fitting of bilateral BAHAs in children with conductive BHL give additional hearing benefits, to investigate the effects of unilateral hearing aids in children with conductive UHL, and to identify different aspects of auditory problems in children with conductive UHL or BHL. STUDY DESIGN: This was a prospective study involving 22 children with either conductive UHL (unaided or with unilateral hearing aid) or conductive BHL (with unilateral or bilateral BAHAs) and 15 controls. METHODS: Baseline audiometry, tone thresholds in a sound field, speech recognition in noise and sound localization were tested without, and with unilateral and bilateral hearing aids. Two questionnaires, MAIS & MUSS and IOI-HA, were completed. RESULTS: Two problem areas were identified in the children with hearing impairment: in reactions to sounds and in intelligibility of speech. An additional BAHA in the children with BHL resulted in a tendency to have improved hearing in terms of better sound localization and speech recognition in noise. Fitting of unilateral hearing aids in the children with UHL gave some supplementary benefit in terms of better speech recognition in noise but no positive effect on ability to localize sound could be detected. Even so, all children fitted with hearing aids - either unilaterally or bilaterally - reported a positive outcome with their devices in the self-assessment questionnaire. CONCLUSIONS: Children with either UHL or BHL displayed several problems within the hearing domain. Fitting of bilateral BAHAs in children with BHL and of a single-sided hearing aid in children with UHL appears to have some supplementary audiological benefits and also renders high patient satisfaction. In order to investigate the possible supplementary effects of hearing aids, a 3-month trial of BAHA on Softband, either unilaterally or bilaterally, may be of value in children with conductive UHL or BHL, respectively.     

Unilateral hearing loss is associated with a negative effect on language scores in adolescents

Objective

To determine if adolescents with unilateral hearing loss (UHL) demonstrate worse language skills than their siblings with normal hearing (NH).

Design

Case-control study of 12–17-year-old adolescents with UHL (20 cases) compared with sibling controls with NH (13 controls).

Methods

Scores on the oral portion of the Oral and Written Language Scales (OWLS) and the Clinical Evaluation of Language Fundamentals (CELF) were the primary outcome measure. Wechsler's Abbreviated Scales of Intelligence (WASI) scores were also used as an outcome measure.

Results

Adolescents with UHL demonstrated worse overall and expressive language scores than controls, (98 vs. 114, P = 0.001; 100 vs. 114, P = 0.006) and had significantly lower full scale (98 vs. 112, P = 0.017), verbal (101 vs. 113, P = 0.032), and performance IQ (95 vs. 107, P = 0.037).

Conclusions

These findings suggest that UHL in adolescents is associated with a negative effect on standardized language scores and IQ. They also demonstrate that the developmental gap between children with UHL and children with NH does not resolve as the children progress into adolescence and may even widen as the children grow older. Therefore, these results strongly encourage implementation of early intervention for children with UHL to prevent speech-language delays. More studies in adolescents are warranted to evaluate educational outcomes.     

感音神经性聋患者听觉皮层BOLD-fMRI研究

目的利用血氧水平依赖的功能磁共振成像（blood oxygenation level dependent functional magnetic resonance imaging,BOLD—fMRI）技术观察感音神经性聋患者纯音刺激时大脑听觉皮层激活情况,探讨感音神经性聋的中枢客观检查方法。方法对22例单侧中重度感音神经性聋患者（耳聋组）和15例健康志愿者（对照组）行听觉刺激BOLD-fMRI检查,比较两组纯音刺激时听觉皮层激活的体积和信号强度。结果对照组纯音刺激单耳时,对侧听觉皮层激活体积和信号强度明显大于同侧（P〈0．01）,表现为对侧半球传导优势;耳聋组刺激健侧时健侧听觉皮层激活体积和信号强度大于患侧,但差异无统计学意义（P〉0．05）。结论感音神经性聋患者纯音刺激健耳时对侧听觉半球传导优势消失,其听觉皮层可能发生了结构重塑。     

Unilateral auditory temporal resolution deficit: A case study

An adult with a unilateral precipitous severe high-frequency hearing loss displayed a selective auditory temporal resolution deficit in the poorer ear, despite excellent word recognition ability in quiet bilaterally. Word recognition performance was inferior in interrupted noise, reverberation, and time-compression conditions when stimuli were presented to the hearing-impaired ear and compared with performance for stimuli presented to the normal-hearing ear or that of normal-hearing listeners. It was suggested that a restricted listening bandwidth was responsible for the performance decrement on the tasks involving temporal resolution. This case illustrates the importance of employing temporal resolution tasks in an audiologic test battery. Such assessment tools may reveal deficits that otherwise may go unnoticed in light of excellent word recognition in quiet.     

Management of unilateral hearing loss

ObjectiveA representative sample of literature regarding unilateral hearing loss (UHL) was reviewed to provide evidence of the effects of UHL and the intervention options available for children with UHL. Considerations during the assessment and management of children with UHL are illustrated using case illustrations.MethodResearch articles published from 2013 to 2015 were searched in the PubMed database using the keywords “unilateral hearing loss”. Articles from 1950 to 2013 were included from a previous literature review on minimal hearing loss [1]. A retrospective review of charts of 14 children with UHL was also conducted.ResultsThe evidence indicates that children with UHL are more likely to have structural anomalies of the inner ear; may face challenges in six different domains, and have six intervention options available. Evidence also indicates that although some children appear to exhibit no delays or difficulties, others have significant challenges, some of which continue into adulthood.ConclusionsChildren with UHL have to be treated on a case-by-case basis. Parent education regarding UHL, its effects, and all available management options is critical so they can make informed decisions. Close monitoring and good communication between professionals in different domains is crucial in order to minimize the potential negative effects of UHL.