The role of intensity upon pitch perception in cochlear implant recipients

OBJECTIVES: Pitch plays a key role in the perception of speech and music, the recognition of a speaker's voice, and in analyzing complex auditory patterns. To date, little consideration has been given to the influence of stimulation level on pitch perception. The aim of this study was to investigate the impact of a sound's intensity on pitch perception in cochlear implant recipients using monopolar stimulation. STUDY DESIGN: Thirteen patients with an average implant use of 4.13 years took part in this study. All patients were implanted with MedEl Combi 40/40+ cochlear implants. METHODS: In the first part of the study, we performed a pitch ranking procedure to confirm that all patients were able to judge pitch changes. Using a visual scale, study participants were then asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity. RESULTS: Eleven (85%) patients were found to perceive a clear change in pitch with changing stimulus intensity. Statistical analysis showed a strong positive correlation in 10 patients (correlation coefficients between 0.99 and 0.71) and a strong negative correlation in 1 patient (r = -0.92). CONCLUSIONS: The results suggest that a distinct relationship exists between pitch perception and intensity of the stimulus. To date, speech coding strategies do not support these findings. Nevertheless, we believe that for the optimized most natural perception of sounds, especially music, the described particularities of pitch perception need to be respected, and further investigations on this topic are necessary.     

声门闭合不良4种发声方式频率与正常人对比分析

目的 :了解声门闭合不良 4种发声方式 (最低音、舒适音、真声最高音和假声最高音 )和不同发音持续最大时间 (最大声时 )的频率变化参数。方法 :用 2 0 3 1型频谱分析仪检测 15 0例功能性声门闭合不良患者 4种发声方式的频率 ,并与正常男女各 3 0例作对比。结果 :从整体看 ,男女最低音的频率 ,闭合不良者明显高于正常人 ,假声最高音的频率则前者明显低于正常人 ;按最大声时不同与正常人比 ,总的趋势是随着最大声时延长 ,最低音和舒适音的频率下降 ,真声和假声最高音的频率上升 ,且有的组间对比差异显著。结论 :声门闭合不良患者发低音和高音的功能同时下降 ;其低音与高音功能随最大声时的延长而增强     

The effects of fundamental frequency level on voice onset time in normal adult male speakers.

The purpose of this study was to examine the effect of fundamental frequency (F(0)) on stop consonant voice onset time (VOT). VOT was measured from the recordings of 56 young men reading phrases containing all 6 English voiced and voiceless stops in word-initial position across high-, medium-, and low-F(0) levels. Separate analyses of variance for the voiced and voiceless stops revealed no significant main effect for F(0) for the voiced stops but a significant F(0) effect for the voiceless stops. Across the voiceless stops, productions at high F(0)s displayed significantly shorter VOTs than productions at low or mid F(0)s. The findings indicated that researchers must take into account the F(0) level at which voiceless stop VOT is measured.     

声带下方收敛角度在声门闭合不全发声困难中可能的作用机理

目的 探讨喉三维CT重建下声带下方收敛角度的测量方法,探索声门闭合不全对声带下方收敛角度的影响,分析声门闭合不全发声疲劳可能的气流动力学原因.方法 采用双源薄层CT,嘱受试者发/i:/音时扫描10例正常人的20侧声带(声门闭合组),深吸气时扫描8例单侧声带麻痹患者的麻痹侧声带(声门闭合不全组),经深吸气时扫描另10例正常人的20侧声带(声带外展组);导入影像数据于Mimics软件,构建声带及气道的3D模型,联合这两模型测量声带下方收敛角度;采用单因素方差分析,比较3组受试者声带下方收敛角度的差异;并尝试采用材料的斜截面应力分配原理进行声门下压力分析,探讨声门下收敛角度对启动发声时声带振动可能的影响.结果 声门闭合组、声门闭合不全组及声带外展组的声带下方收敛角度分别为33.49°±3.75°、55.03°±2.61°及75.02°±7.32°,三组间差异有统计学意义(P<0.01),声带下方收敛角度随声门闭合不全程度增加而增加.结论 声带下方收敛角度可以通过声带及气道的3D模型进行有效测量,声门闭合不全程度增加会引起该角度增大,可能会导致声门下压力作用于声带下方的剪切力和正应力的分力发生变化,从而引起发声困难.     

The effects of distraction on smooth pursuit in normal subjects

Smooth pursuit eye movements made in response to 5 and 20% targets were studied in young and old subjects. Tracking of a target was carried out both with no competing stimuli and while auditory and visual distractions were presented. Only tracking the target against a projected background significantly impaired pursuit. It did so in both age groups, by reducing pursuit gain and also by eliciting 'anticipatory saccades', which took the eyes ahead of the target to a new fixation point for 0.5 s or longer. Elderly subjects showed a significantly greater number of such interruptions, however, suggesting that continuous performance of the tracking task could be more readily disrupted in this group. These findings may arise from changes in the way in which elderly individuals process incoming sensory information.     

Influence of aging on hyaluronic acid concentration in the vocal folds of female rats

The vibration of the vocal fold lamina propria is an important factor involved in vocal production and aging may change the amount of hyaluronic acid in the vocal fold leading to dysphonia.AimsThis study compares the concentration of hyaluronic acid in vocal folds of aged and young female rats. Study design: experimental.Materials and MethodsWe used the vocal cords of 13 female rats divided into two groups: five aged rats and eight young ones. The tissue concentration of hyaluronic acid was determined using the fluorimetric method with the hyaluronic acid binding-protein coated on plates of enzyme-linked immunosorbent assay (ELISA), conjugated with biotin. Europium-labeled streptavidin was added and, after europium release with the use of enhancement solution, the final fluorescence was measured in a fluorometer.ResultsWe found the following concentrations of hyaluronic acid in vocal fold according to the group: 581.7 ng/mg in old female rats and 1275.6 ng/ mg in young female rats. Statistical analysis showed differences between groups.ConclusionsThe vocal folds of old female rats have a lower concentration of hyaluronic acid when compared to such concentration on the vocal folds of young female rats.     

Posturography frequency analysis of sound-evoked body sway in normal subjects

Sound-evoked activation of the vestibular system has been suggested for a long time, and myogenic potentials have been recorded at the level of different muscular groups while a high intensity sound was applied. The aim of this study was to analyse sound-evoked postural responses in normal subjects and to correlate them with the activation of the vestibular system. Body sway was measured by posturography and elaborated through spectral frequency analysis in 40 healthy volunteers in the basal condition and after applying a sound stimulus monoaurally. Spectral frequency analysis results showed a significant increase, in presence of stimulus, of body sway at low and middle frequencies only on the lateral plane and in the closed-eyes condition. As it seems that these frequency ranges are mainly under vestibular control, our results suggest that sound activates specifically the vestibular system, and posturography during sound stimulation represents an alternative approach to assess vestibular function.     

不同频率与强度差值对正常人错配负反应的影响

目的 研究频率与强度的声学差异对正常人错配负反应(mismatch negativity,MMN)的影响.着重观察频率与强度的差异对正常人MMN潜伏期及幅度的影响以及可以引出MMN的声学差异的阈值.方法 24例受试者纯音听力测试各个频率纯音听阈均在20 dB HL以内.应用美国智听公司Smart EP听觉诱发电位仪测量MMN,观察频率与强度的差异对正常人MMN潜伏期及幅度的变化规律.结果 随着频率差异或强度差异的减小,MMN潜伏期逐渐延长,MMN振幅逐渐降低.结论 MMN图形稳定,是听觉分辨的客观神经生理检查的重要指标.     

Concentration and distribution of hyaluronic acid in human vocal folds

OBJECTIVE/HYPOTHESIS: To evaluate the concentration and distribution of hyaluronic acid (HA) in human adult vocal folds. STUDY DESIGN: Experimental study. METHODS: Histologic samples of the anterior, middle, and posterior regions of the vocal folds were studied to determine the tissue distribution of HA. The HA was traced with hyaluronan-binding proteins (HAPB) from bovine cartilage. Chemical bonds were detected through the avidin-biotin immunoperoxidase method. A control with the specific Streptomyces hyalurolyticus hyaluronidase was conducted to avoid false-positive results. The concentration levels of HA were determined through a fluorescence-based assay method with the same HAPB and europium-labeled streptavidin. RESULTS: Women presented higher HA concentrations than men in every studied region of the vocal folds and overall HA concentration levels twice as higher. In regard to the distribution of HA, the macula flavae and the vocal fold intermediate and deep layers presented marked staining, with moderate staining around the vessels, on the gland capsules, and the connective tissue surrounding the vocal fold muscular fibers. CONCLUSIONS: HA is diffusely distributed along the vocal folds; the profuse amounts of HA observed in the female vocal folds may be related to impact absorption, acting as a protective factor against the characteristic high vibration frequency.