对称性聋患者单耳助听后双耳言语识别率差别探讨

目的通过检测对称性聋患者单耳助听后双耳言语识别率的差别来进一步研究听觉剥夺效应。方法选取右耳助听4～5年的双耳对称性感音神经性聋患者15名,在标准隔声室中,测试其双耳的纯音气导和骨导听闻,然后再采用汉语普通话单音节词表分别进行左右裸耳言语识别率测试,并将所得数据进行对比研究。结果15名受试者右耳配戴助听器前及配戴4～5年后两耳间平均听阈无显著性差异（P〉0．05）;受试者右耳助听前及助听4～5年后左、右耳平均听阀前后无显著性差异（P〉0．05）;右耳助听4～5年后,受试者左、右耳裸耳言语识别率存在显著性差异（t=2．76,P=0．02〈0．05）。结论对称性感音神经性聋患者单耳助听后裸耳平均听阈无显著改变,但非助听耳言语识别能力显著下降。     

老年人重度和极重度聋双耳助听效果评价

目的评价老年人重度和极重度聋双耳助听效果。方法比较单耳和双耳助听后的言语识别率。结果　单耳助听后的言语识别率,单音节词为７７．５３±２．０７％,双音节词为８６．８２±４．３６％。双耳助听后的言语识别率,单音节词为８６．４７±１．８７％,双音节词为９１．６５±２．１８％。双耳助听效果显著优于单耳。结论双耳助听不仅可显著改善言语分辨能力,而且可使声源定向能力亦获显著改善。非常适合双耳重度和极重度聋的老年人。     

聋儿配戴助听器后使用无线调频语训系统的效果评估

目的：研究和比较全数字助听器与无线调频语训（FM）系统不同结合方式对重度听力损失儿童的助听效果，方法：聋儿双耳分别配戴全数字助听器，双耳全数字助听器结合单耳FM系统，双耳全数字助听器结合双耳FM系统，在安静和噪声环境中，以不同强度的言语声测试言语可懂度，比较在安静环境和噪声环境中使用与不同使用FM系统及单耳使用与双耳同时使用的助听效果。结果：在安静和噪声环境下，使用FM系统的言语可懂度优于不使用该系统（P＜0．05），单耳使用该系统和双耳使用该系统无明显差异（P＞0．05）。结论：聋儿配戴助听器使用无线调频语训系统在安静和噪声环境下言语可懂度高于不使用该系统者。     

重度聋幼儿助听器助听效果的评价

应用功能增益法评估 4 4名重度聋幼儿配戴助听器后的助听效果 ,追踪观察三年 ,全部患儿的助听效果均较初诊时好 (P <0 .0 5 ) ,其中双耳配戴助听器患儿较单耳配戴者效果更好     

108例重及极重度聋幼儿助听效果观察

目的　为双耳重、极重度感音神经性聋患儿选配助听器 ,并进行定期调试 ,观察助听效果。方法　用功能增益法评估助听器效果。结果　佩戴助听器 1～ 3年后的助听器效果较初戴时好 ,两者之间有显著性差异 (P<0 .0 1) ,高频差异更大。结论　聋儿佩戴经验配后的助听器 ,听敏度特别是高频部分的听敏度有提高     

聋儿助听效果的影响因素

目的:探讨影响聋儿助听效果的因素。方法:调查208例聋儿(335耳)助听情况,声场测听评估助听效果;对助听效果欠理想的163耳重新验配,对比分析其前后的助听效果及其影响因素。结果:335耳助听效果最适合及适合的由原164耳(49.0　%)增加到265耳(79.1%);较适合及看话的由原123耳(36.7%)下降到63耳(18.8%);无效的由原48耳(14.3%)减为7耳(2.1%)。助听阈值明显减小(P<0.001)更集中于香蕉图内,尤其是高频补偿改善显著。结论:纯音测听和助听评估及复诊是影响聋儿助听效果的主要因素;导致助听效果欠理想的直接原因主要为助听器调试不当和不适配,耳模作用亦值得重视。     

中度和重度聋儿助听后早期听觉能力及言语可懂度发育

目的：评价耳聋儿童助听后1年内听觉及言语能力发展变化趋势,探讨耳聋程度对聋儿的听觉及言语发育水平的影响,为聋儿的有效康复提供临床参考资料。方法：患儿29例,男19例,女10例。助听器选配年龄3～8岁,平均5．6岁。根据听力损失程度将患儿分为中度听力损失组（14例）和重度听力损失组（15例）。分别使用听觉行为分级（CAP）和言语可懂度分级（SIR）问卷在助听前及助听后1、3、6、9、12个月时对患儿的听觉能力及言语可懂度发育情况进行评估。结果：经单因素方差分析,中度和重度聋患儿CAP平均得分在助听前差异有统计学意义（P〉0．05）。在助听后1、3、6、9、12个月均差异无统计学意义（P〉0．05）。同样中度和重度聋患儿SIR平均得分在助听前差异有统计学意义（P〈0．05）。在助听后1、3、6、9、12个月均差异无统计学意义（P〉0．05）。中度聋患儿cAP平均得分助听前与助听后6、9、12个月差异有统计学意义（P〈0．05）。中度聋患儿SIR平均得分助听前与助听后6、9、12个月差异有统计学意义（P〈0．05）;助听后1个月与12个月差异有统计学意义（P〈0．05）。重度聋患儿CAP平均得分助听前与助听后3、6、9、12个月差异有统计学意义（P〈0．05）,助听后1个月与9、12个月差异有统计学意义（P〈0．05）。重度聋患儿SIR平均得分助听前与助听后3、6、9、12个月差异有统计学意义（P〈0．05）,助听后1个月与6、9、12个月差异有统计学意义（P〈0．05）。结论：中度和重度聋组患儿助听后1年内早期听觉及言语能力有显著提高,但各自有不同的发育特点和规律。     

可接受噪声级测试在单、双耳佩戴助听器效果评估中的应用

目的 通过比较双侧中重度听力损失患者在单、双耳助听下的可接受噪声级(acceptable noise level,ANL),探讨ANL对助听器验配及预测助听效果的作用.方法 选取15例双侧中重度听力损失患者,分别测得双耳未助听、左耳助听、右耳助听和双耳助听状态下的最舒适响度级(most comfortable levels,MCL)、最大背景噪声级(background noise level,BNL),并计算得到ANL值(ANL=MCL-BNL),对结果进行统计学分析.结果 15例受试者双耳未助听、左耳助听、右耳助听及双耳助听四种状态下测得的ANL值分别为18.87±5.26、12.60±2.47、12.00±2.90、5.13±1.25 dB S/N;MCL值分别为80.40±9.28、63.73±5.15、62.27±5.36、61.80±6.05 dB HL;BNL值分别为61.67±6.14、51.13±3.94、50.27±4.50、56.67±5.16 dB HL;左耳助听与右耳助听下的ANL值差异无统计学意义(P>0.05);单、双耳助听下与未助听的ANL值差异均具有统计学意义(P<0.05);双耳助听状态下ANL值显著低于单耳助听(P<0.05).结论 ANL值较低耳更利于助听器验配,佩戴助听器能有效提高听障患者对噪声的接受能力,并且双耳佩戴助听器的效果明显优于单耳.     

婴幼儿助听效果评估

随着新生儿听力筛查工作的开展,诸多低龄儿童听力障碍得以早期确诊和干预,接受助听器验配的人群年龄呈低龄化趋势。Uus K[1]报道169487名婴幼儿中有169名被确诊患有双侧中重度听力损失,而听力障碍患者中,平均配戴助听器的年龄是16周。澳大利亚Robishaw(1995)的研究表明,为耳聋患者在出生后6个月内验配助听器,其言语和语言能力与听力正常小儿相差无几,且比配助听器迟的小儿效果要好;良好的助听效果对于改善聋儿的听力、听觉自我反馈监听、言语表达十分重要,因此有效的听觉补偿、对听力补偿的评价就显得尤为重要。然而,由于婴幼儿自身发育等…     

言语测听评价聋幼儿助听效果分析

助听器的主要功能是改善患者的言语听力 ,佩戴助听器后言语分辨能力提高的程度 ,是判断助听效果的最直接的依据。但是对于学语前耳聋的患儿 ,因为无语言基础 ,评价助听效果只能用功能增益法即用 2 5 0～ 40 0 0Ｈｚ的啭音作为测试声 ,确定聋儿听力损失经过助听补偿后的音频感受范围是否在正常人听觉言语区域 ,判断该聋儿佩戴的助听器是否合适。此方法有一定局限性 ,它测试所发出的啭音或窄带噪声 ,而言语声是多频率的复合音 ,因此 ,单靠功能增益法无法评估助听器的真实效果。近年来 ,对在训及家庭训练的聋儿 ,佩戴助听器后听力跟踪与训练相…     

Monaural versus binaural auditory brainstem response threshold to clicks masked by high-pass noise in normal-hearing subjects

Monaural and binaural auditory brainstem response (ABR) thresholds to clicks masked by high-pass noise with a cut-off frequency of 1,590 Hz were measured in normal-hearing subjects. In sleeping normal-hearing subjects, the 1,000-Hz frequency-specific ABR threshold for binaural stimulation amounted to 12 dB nHL and for monaural stimulation to 18 dB nHL. No significant difference in latency was found between monaural and binaural stimulation. Binaural ABR threshold was 5.5 +/- 1.4 dB (mean +/- SEM) lower than the mean monaural ABR threshold. This difference is statistically significant (Student's t test; p less than 0.005).     

Listeners who prefer monaural to binaural hearing aids

Four patients who preferred monaural as compared with binaural amplification were evaluated. For these patients, audiometric data, recognition performance on a dichotic digit task, and monaural and binaural hearing aid performance using four amplification strategies (National Acoustic Laboratories-Revised, a speech in noise algorithm, multiple-microphone arrays, and frequency modulated [FM]) are described. The results of dichotic testing using a one-, two-, and three-pair dichotic digit task in free- and directed-recall conditions indicated a left-ear deficit for all subjects that could not be explained by peripheral auditory findings or by a cognitive-based deficit. The results of soundfield testing using a speech in multitalker babble paradigm indicated that when listening in noise, there was little difference between aided and unaided word-recognition performance, suggesting that the binaural hearing aids originally fit for each patient were not providing substantial benefit when listening in a competing babble background. Word-recognition performance when aided monaurally in the right ear was superior to performance when aided monaurally in the left ear and when aided binaurally. The only successful binaural amplification strategy was the FM system. The results indicate that listeners with an auditory-based deficit in dichotic listening may function better with a monaural hearing aid fitting or with an assistive listening device such as an FM system. The findings also suggest that a test of dichotic listening is an important component in the evaluation of patients being considered for amplification.     

Processing Temporal Modulations in Binaural and Monaural Auditory Stimuli by Neurons in the Inferior Colliculus and Auditory Cortex

Processing dynamic changes in the stimulus stream is a major task for sensory systems. In the auditory system, an increase in the temporal integration window between the inferior colliculus (IC) and auditory cortex is well known for monaural signals such as amplitude modulation, but a similar increase with binaural signals has not been demonstrated. To examine the limits of binaural temporal processing at these brain levels, we used the binaural beat stimulus, which causes a fluctuating interaural phase difference, while recording from neurons in the unanesthetized rabbit. We found that the cutoff frequency for neural synchronization to the binaural beat frequency (BBF) decreased between the IC and auditory cortex, and that this decrease was associated with an increase in the group delay. These features indicate that there is an increased temporal integration window in the cortex compared to the IC, complementing that seen with monaural signals. Comparable measurements of responses to amplitude modulation showed that the monaural and binaural temporal integration windows at the cortical level were quantitatively as well as qualitatively similar, suggesting that intrinsic membrane properties and afferent synapses to the cortical neurons govern the dynamic processing. The upper limits of synchronization to the BBF and the band-pass tuning characteristics of cortical neurons are a close match to human psychophysics.     

Interaural time coincidence detectors are present at birth: evidence from binaural interaction

Binaural processing of sounds in mammals is presumably initiated within the auditory nuclei of the caudal pons. The binaural difference waveform (BD) can be derived from the sum of the waveforms evoked by right monaural clicks plus left monaural clicks minus the waveform evoked by binaural clicks. In adults, the BD's first positive peak (beta) is large only for stimuli with interaural time differences (ITDs) that produce a fused acoustic percept. Humans at birth can localize and discriminate sound sources, but their head circumference is about two-thirds of an adult head. In order to test whether beta is related to head circumference, we recorded beta in human neonates as a function of ITD. Binaural clicks with ITDs ranging between 0 and 1000 micros were used to derive BD waveforms in 34 neonates. For ITD=0, beta was detectable in 56% of newborns. The incidence of beta detection then decreased as ITD increased. Only 9% of the babies had detectable beta for all ITDs. No correlation was found between the existence of beta and other properties of the monaural or binaural auditory brainstem response. The finding that for some infants beta was present for all ITDs up to 1.0 ms suggests that there is no recalibration of brainstem delay lines with head growth. Our data suggest that the brainstem auditory pathway for detecting interaural time differences in the adult is probably present at birth. Maturational factors such as increased myelination and greater firing synchrony probably improve the detectability of beta with age. The second peak in the BD waveform (delta) was highly correlated with the existence of wave VI in the binaural and monaural waveforms.     

Individual differences in auditory electric responses: comparisons of between-subject and within-subject variability. II. Amplitude of brainstem Vertex-positive peaks

Recently, we (Lauter & Loomis, 1986) reported variability measures of the latency of five vertex-positive auditory brainstem response (ABR) peaks collected under a repeated-measures experimental design. Seven subjects were tested, each on eight separate sessions, for brainstem auditory evoked response to monaural right, monaural left, and binaural stimulus presentation. This paper presents variability measures for amplitudes of the same series of responses. Three types of variability measurement were made: 1) amplitude of each peak of the response to monaural right, monaural left, and binaural stimulation; 2) amplitude difference for each peak comparing binaural with right, and binaural with left; and 3) amplitude difference comparing binaural with the sum of the amplitudes of the two monaural responses. As in the previous report, between-subject variability and within-subject variability were expressed using a ratio of mean divided by standard deviation (this is the reciprocal of Pearson's Coefficient of Variation, and will here be referred to as the Coefficient of Stability, or Cs). For all amplitude comparisons, Cs profiles indicate that: 1) within-subject stability (i.e., consistency) is significantly greater than between-subject stability, 2) both within- and between-subject stability measures are sensitive to both peak and ear of presentation, and 3) stability profiles for individual subjects show individual differences and similarities, and are replicable over time. The variability measure also provides evidence of an ear asymmetry at peak III which has been noted in other ABR studies.     

Acceptance of noise with monaural and binaural amplification

The present study investigated the effects of monaural and binaural amplification on speech understanding in noise and acceptance of noise for 39 listeners with hearing impairment. Results demonstrated that speech understanding in noise improved with binaural amplification; however, acceptance of noise was not dependent on monaural or binaural amplification for most listeners. These results suggest that although two hearing aids maximize speech understanding ability in noise, most individuals' acceptance of noise, which is directly related to hearing aid use, may not be affected by the use of binaural amplification. It should be noted that monaural amplification resulted in greater acceptance of noise for some listeners, indicating that binaural amplification may negatively affect some individuals' willingness to wear hearing aids. It should also be noted that interaural differences in acceptance of noise might exist for some listeners; therefore, if only one hearing aid is fitted, monaural ANLs should be measured.     

Asymmetric hemodynamic responses of the human auditory cortex to monaural and binaural stimulation

Applying whole-head functional magnetic resonance imaging (fMRI) in 11 neurologically intact subjects, hemodynamic responses to mon- or binaurally presented auditory stimuli were measured. To expand on previous studies in this research area, we used tones and consonant–vowel (CV) syllables. In one group of subjects (n=6) the perceived loudness of the monaurally presented stimuli were adjusted so that they matched the loudness of the binaurally presented stimuli. In a second group (n=5) no loudness adjustment was performed, thus the monaural stimuli were perceived less loud (10 dB) than the binaural stimuli. These extensions allowed us to test whether CV syllables and tones produce different contralaterality effects (stronger hemodynamic responses in the auditory cortex contralateral to the stimulated ear) and whether binaural stimulation results in stronger activations in the auditory areas than during both monaural stimulation conditions (binaural summation) independent of loudness influences. In summary, we obtained the following findings: (1) strong contralaterality effects during monaural acoustic stimulation in the posterior superior temporal gyrus (STG) comprising the planum temporale and the dorsal bank of the superior temporal sulcus to CV syllables and tones; (2) the hemodynamic responses to contralaterally presented stimuli (during the monaural conditions) were mostly stronger than those to binaurally presented CV syllables; (3) there was no interaction between stimulus type and the size of the contralaterality effect; (4) there was no indication of binaural summation, rather we found stronger hemodynamic responses to the sum of both monaural stimulations (right and left ear) than to binaural stimulation in all auditory areas; (5) there were generally stronger hemodynamic responses to CV syllables than to tones in the posterior STG, while the hemodynamic responses to tones were stronger in the anterior part of the STG (temporal pole); and finally (6) there was no general difference in terms of hemodynamic response in the auditory cortex between the two groups when receiving either loudness-matched or non-loudness-matched monaural stimulation. These findings are discussed in the context of the underlying neurophysiological mechanisms, the peculiarities of functional fMRI, and the direct access and callosal relay models of hemispheric lateralization.     

Conductive hearing loss during infancy: effects on later auditory brain stem electrophysiology.

Long-term effects on auditory electrophysiology from early fluctuating hearing loss were studied in 27 children, aged 5 to 7 years, who had been evaluated originally in infancy. For controls (Group A), infant auditory brain stem responses (ABRs) were normal from birth to age 2 years. A second group (Group B) had intermittent conductive hearing loss. A third group (Group C) had more abnormal ABRs during infancy than Group B and more severe and frequent conductive hearing loss. For this follow-up study, all children had normal peripheral hearing at test. ABRs were obtained to monaural and binaural stimuli. Binaural interaction (BI) in the ABR was assessed in difference traces, derived by subtracting summed binaural from summed monaural waveforms. Controls differed from both groups with early hearing loss for wave III and wave V latencies and interpeak I-III and I-V latencies. There was a significant difference in the presence of BI. Eight of 9 A subjects and 8 of 9 B subjects, but only 4 of 9 C subjects, had demonstrable BI. Findings suggest that early fluctuating hearing loss disrupts later auditory brain stem electrophysiology.     

Frequency dependence of the binaural interaction component of the auditory brainstem response

The frequency dependence of the binaural interaction component of the auditory brainstem response was examined. Subjects included 24 with normal hearing and 5 with severe high-frequency losses. Tone pips of 100 and 80 dB pe SPL at 1 000 and 4 000 Hz were presented monaurally and binaurally. The binaural interaction component was derived by subtracting the binaural response from the addition of the left and right monaural responses. The binaural interaction component was produced by both 1 000 and 4 000 Hz, although it was larger and more reliable with 1 000 Hz. The absence of responses to 4 000 Hz in cochlear-impaired subjects did not alter appreciably the morphology of the binaural interaction component to 1 000 Hz. The correspondence between the binaural interaction component and the masking level difference was not good.     

Measures of the binaural interaction component in human auditory brainstem response using objective detection criteria

The occurrence of binaural interaction in humans has been demonstrated using auditory brainstem response (ABR). A distinctly binaural potential, beta, is derived by subtracting the ABR recording evoked by binaural clicks from the monaural aggregate, i.e., the sum of the two corresponding ABR recordings evoked by monaural clicks. However, few clinical data are available, possibly because the beta-wave is considered an elusive response due to a low signal-to-noise-ratio. In the present study, beta-wave latency, amplitude and area were evaluated for 10 subjects with normal hearing using automatic analysis and averaging based on a large number of stimulations. The efficacy of the beta-wave measures was assessed using different stimulus rates, as binaural interaction is known to decrease with increasing stimulus rate. It was found that the beta-wave given by automatic analysis demonstrated known characteristics of binaural interaction in human ABR, i.e. the absence of binaural interaction during wave III, significant binaural interaction during wave V and a significant decrease in binaural interaction when the stimulus rate was increased. These findings suggest that a beta-wave in the binaural difference waveform can be detected and quantified using automatic analysis, thus it is suitable for clinical studies, at least for patients with normal hearing thresholds.