声带振动模式及其变异的语音及电声门图分析

为更直观有效地了解正常男女性声带疾病患者在发声和声带振动的频率、幅度及声门开放、闭合过程的速度变化，我们采用嗓音测试仪观察正常男、女性声带振动的模式和声带疾病组的变异情况。将语言信号和电声门图信号的各个参数进行比较（ｔ检验）分析得出，健康男、女性波形规则均匀，女性频率快、幅度小，男性较女性的声门开放、闭合速度为快；疾病组中波形变化较大，频率或幅度都有不同的变化；嘶哑程度也不同地影响了声带运动中的开放和闭合过程。     

肺结节螺旋CT检测的螺距效果

目的：比较螺旋CT在检测肺结节时增加螺距和常规螺距的不同效应。材料与方法：对100例转移癌肺结节患者以1.0螺距行胸部螺旋CT扫描：随机分别以1.2（n=33）、1.5（n=34）与2.0（n=33）的增加螺距在同样的扫描断面对患者行进一步扫描;配对分析结节的数量、大小和分布。结果：在以螺距1.5和2.0的扫描上发现漏检病变的倾向,但均无显著性差异;对于螺距1.2,1.5与2.0的相关系数分别为r=.982,k=.977与r=.989。螺距为2.0的扫描因其显示小的孤立性结节的清晰度很差而低估了病变分期。结论：增加螺距与否对扫描检出效果通常无大影响;但对于孤立性结节患者,增加螺距扫描会低估疾病。对于肺转移性疾病的最初分期,扫描螺距宜小于1.5。     

Depth electrode recordings show double dissociation between pitch processing in lateral Heschl’s gyrus and sound onset processing in medial Heschl’s gyrus

Pitch is a fundamental perceptual attribute of sounds. Our ability to discriminate, separate, and identify sounds relies heavily on pitch. Recent neuroimaging studies in humans have provided converging evidence for the existence of a “pitch center”—a region on the superior temporal plane (STP) lateral to Heschl’s gyrus specialized in pitch extraction—but a direct confirmation is still missing. Intracerebral recordings in humans are ideally suited for such a confirmation. Here we report results from depth electrode recordings in a patient undergoing investigation for epilepsy. We demonstrate a double dissociation between responses from the medial and lateral STP around Heschl’s gyrus to the onset of sound energy and the onset of pitch. Three pieces of evidence support this finding: (1) the response to sounds that do not contain pitch is small in the lateral STP compared to the medial STP; (2) sounds that contain pitch evoke a strong response in the lateral STP; (3) at the transition from noise to a specialised noise-like, but tonal, sound referred to as iterated ripple noise, where the onset of pitch is the sole acoustic event, only the lateral contact showed a response. Our results provide direct evidence for a pitch-specific area on lateral STP with intracranial recordings from the human auditory cortex.     

Adaptation of the angular vestibulo-ocular reflex to head movements in rotating frames of reference

Head movements in a rotating frame of reference are commonly encountered, but their long term effects on the angular vestibulo-ocular reflex (aVOR) are not well understood. To study this, monkeys were oscillated about a naso-occipital (roll) axis for several hours while rotating about a spatial vertical axis (roll-while-rotating, RWR). This induced oscillations in roll and pitch eye velocity and continuous horizontal (yaw) nystagmus. For several hours thereafter, simple roll in darkness induced horizontal nystagmus and pitch and roll oscillations. The rising and falling time constants of the horizontal velocity indicated that the nystagmus arose in velocity storage. The continuous nystagmus was correlated with a phase shift of vertical eye velocity from 90° to 0° re head position. As the phases reverted toward pre-adaptive values, the horizontal velocity declined. Similar yaw nystagmus and pitch and roll velocities were produced by oscillation in roll after adaptation with roll and horizontal optokinetic nystagmus (OKN), but not after adaptation with pitch-while-rotating (PWR). Findings were explained by a model that shifted the roll orientation vector of velocity storage toward the pitch axis during adaptation with RWR and Roll & OKN. This shift produced modulation in vertical eye velocity in the post adaptive state, which was approximately in phase with roll head position, generating horizontal nystagmus. Similar orientation changes to prolonged exposure to complex motion environments may be responsible for producing post-stimulus motion sickness and/or mal de debarquement. Supported by DC007847, EY04148, DC05204, EY01867, DC05222.     

The neural bases underlying pitch processing difficulties

Normal listeners are often surprisingly poor at processing pitch changes. The neural bases of this difficulty were explored using magnetoencephalography (MEG) by comparing participants who obtained poor thresholds on a pitch-direction task with those who obtained good thresholds. Source-space projected data revealed that during an active listening task, the poor threshold group displayed greater activity in the left auditory cortical region when determining the direction of small pitch glides, whereas there was no difference in the good threshold group. In a passive listening task, a mismatch response (MMNm) was identified for pitch-glide direction deviants, with a tendency to be smaller in the poor listeners. The results imply that the difficulties in pitch processing are already apparent during automatic sound processing, and furthermore suggest that left hemisphere auditory regions are used by these listeners to consciously determine the direction of a pitch change. This is in line with evidence that the left hemisphere has a poor frequency resolution, and implies that normal listeners may use the sub-optimal hemisphere to process pitch changes.     

Pitch and lexical tone perception of bilingual English–Mandarin-speaking cochlear implant recipients,hearing aid users,and normally hearing listeners

Abstract

Objectives

The purpose of this current study was to investigate whether pitch, lexical tone, and/or speech-in-noise perception were significantly correlated for Singaporean teenagers or adults who spoke both Mandarin and English.

Methods

Thirty-three normal hearing or near-normal hearing listeners who did not use a hearing device (NNH group), eight postlingually deafened cochlear implant (CI) recipients (CI group), and three postlingually deafened bilateral hearing aid (HA) users (HA group) were recruited. All participants were bilingual Mandarin–English-speaking Singaporean residents. Participants were assessed on tests of pitch-ranking, lexical tone perception, and speech-in-noise.

Results

The NNH group scored significantly better than the CI group for all tests and subtests. There were no significant differences for the pitch test between the HA group and either the CI or NNH group. However, HA users scored significantly better than the CI group, and more aligned with the NNH group's scores for both the lexical tone and Mandarin speech-in-noise test. There were highly significant moderate positive correlations between all three tests.

Discussion

Overall, the performance of the CI users in this study indicates that CI recipients still struggle on pitch-related auditory perception tasks. Additionally, although the test scores from the HA users were better than the CI recipients, they were not as good as the NNH listeners. The significant moderate correlations between all three tests indicate that there is at least some degree of overlap in the skills required to accurately perceive these stimuli.

Conclusion

The overall results suggest that CI users, and to a lesser extent HA users, still struggle with complex auditory perceptual tasks, particularly when it requires the perception of pitch. However, it may be possible that training one of these skills (e.g. musical pitch) may then generalize to other tasks (e.g. lexical tone and/or speech-in-noise). This is important for counseling, as well as for planning effective rehabilitation programs.     

Musicians and non-musicians’ different reliance of features in consonance perception: A behavioral and ERP study

ObjectiveThe aim of this study was to compare the different features that musicians and non-musicians rely upon when they discern consonant and dissonant intervals. Previous studies have addressed this issue from the perspective of either the frequency ratio (Western music theory) or the frequency difference (psychoacoustics), but have not considered both features in a single and balanced study.MethodsTwelve musicians and twelve non-musicians judged musical consonance at various 50–500 Hz intervals, orthogonally selected from across the “pitch interval” and “roughness” spectrum. Both behavioral and event-related potential (ERP) data were collected separately.ResultsBehavioral results demonstrated that while musicians relied upon pitch intervals (between perfect fifths and tritones, with 95% accuracy), non-musicians performed around chance. The latter performance could, however, be sub-divided into “rough tritone and non-rough perfect-fifth” (70–80%) and “non-rough tritone and rough perfect-fifth” combinations (25–30%), suggesting non-musicians’ reliance on the roughness dimension. ERP components revealed corresponding P2 (200–250 ms) amplitude differences in the Fz and Cz channels for the “tritones vs. perfect fifths” comparison in musicians, and by the “rough vs. non-rough” comparison in the non-musicians. In addition, N1 (∼100 ms) and N2 (300–400 ms) components also revealed difference in Fz, F3, F4, FCz, Cz and CPz electrodes for “tritones vs. perfect fifths” in musicians. In the non-musicians, a stronger negative N2 for rough than for non-rough stimuli was found at F4 and Cz.ConclusionTogether, these results suggest that musicians and non-musicians rely upon pitch intervals and sensory roughness, respectively, for consonance/dissonance perception.SignificanceTo our knowledge, this is the first study to compare independently across the pitch interval and roughness spectrum. Our results further support the brain plasticity as a result of musical training in consonance perception.     

Music Perception and Cognition: A Review of Recent Cross‐Cultural Research

Experimental investigations of cross‐cultural music perception and cognition reported during the past decade are described. As globalization and Western music homogenize the world musical environment, it is imperative that diverse music and musical contexts are documented. Processes of music perception include grouping and segmentation, statistical learning and sensitivity to tonal and temporal hierarchies, and the development of tonal and temporal expectations. The interplay of auditory, visual, and motor modalities is discussed in light of synchronization and the way music moves via emotional response. Further research is needed to test deep‐rooted psychological assumptions about music cognition with diverse materials and groups in dynamic contexts. Although empirical musicology provides keystones to unlock musical structures and organization, the psychological reality of those theorized structures for listeners and performers, and the broader implications for theories of music perception and cognition, awaits investigation.     

A voice-generation system using an intramouth vibrator

This paper proposes and evaluates an intramouth vibrating voice-generation system we have developed to aid alaryngeal speech. The system fixes a vibrator in artificial teeth as a substitute for a glottal sound source, and proper sound control improves the speech. With this system, we controlled the substitute glottal sound with intraoral pressure, which increases for voiceless consonants, for clearer speech. In addition, the system controls the pitch of speech using pressure from a finger. This concise pitch control is available to all patients for more natural speech. We tested two methods of pitch control by finger pressure: one in which finger pressure directly determines the pitch, and the other in which finger pressure is converted into binary commands of voice and accent that execute pitch pattern generation. Conventional pitch control with expiration pressure served as a reference. Without voicing control, less than 50% of syllables were identified correctly. Voicing control improved this rate to 60%. Similarly, voicing control improved misidentification of voiceless consonants to corre-sponding voiced ones from 30% to 10%. Binary pitch control with finger pressure performed better than direct pitch control and was perceived as natural as direct pitch control with expiration pressure.