厅堂脉冲响应与人耳感知模型的研究

在分析厅堂脉冲响应的过程中引入了人耳听觉模型,在听觉生理学和心理学研究成果的基础上,建立了针对厅堂音质研究的人耳感知模型。该模型模拟了基底膜的频率选择特性,内毛细胞的半波整流特性以及神经纤维的时域累积特性等一系列人耳感知过程。通过对厅堂脉冲响应的实例分析发现,基于人耳感知模型的厅堂脉冲响应分析具有明显的优点。与现有的客观参量比较,该模型的计算结果与主观感觉之间存在更为紧密的联系。     

人耳音高感知的心理声学基本理论

在简述人耳听觉构造和基底膜选频特性的基础上,详细介绍了解释人耳音高感知现象的两个心理声学基本理论,即"部位学说"和"时间论",同时介绍了部位学说和时间论在解释人耳音高感知存在的不足,以及人耳音高感知的心理声学模型.     

鼻辅音感知线索研究

语音识别系统的性能受许多因素的影响,如不同的说话人、说话方式、环境噪音等。为了提高系统的识别率和稳定性,一种重要的解决方法是寻找更好的、高强健性的基于人耳听觉感知特性的感知线索。基于此,三维深度研究方法（3DDS）被发明,用来探究语音信号在人耳内部的感知线索,并已成功的运用于对摩擦音和爆破音的感知线索识别。本文将这种方法拓展到鼻辅音的感知线索研究。在三个感知实验结果分析的基础上,定义了冗余感知线索和次要感知线索,并找到了/m/的感知线索是大约位于363~1250Hz的语音部分,/n/的感知线索是大约位于939~2826Hz的语音部分。      

船舶噪声合成与听觉感知分析

船舶噪声人耳听觉感知训练是提高声呐员目标识别能力的重要手段,但是实录各类船舶在各个状态下的辐射噪声作为训练噪声样本根本无法实现,而且实录船舶辐射噪声易受环境噪声和海洋声信道传播的影响,无法清晰且不失真地呈现船舶的状态信息。依据人耳听觉感知的临界带通特性,提出了通过临界带通滤波和线谱迭加合成方法合成船舶辐射噪声的方法,并对舰船辐射噪声的原始声和合成声进行了听觉感知特性分析。研究结果表明辐射噪声的合成声与原始声在尖锐度、粗糙度和波动强度三个音色属性方面一致,可以作为船舶噪声人耳听觉感知训练中的噪声样本。     

基于感知加权滤波的卡尔曼滤波语音增强

结合人耳听觉掩蔽效应,提出一种基于听觉感知加权的卡尔曼滤波语音增强方法。由于人耳对语音的感知主要是通过语音信号频谱分量幅度获得的,引入听觉感知加权滤波器在频域上使共振峰区域残留噪声更多,而共振峰之间及语音幅度谱较低的区域残留噪声减少,这样符合人耳的听觉特性,从而使得主观感觉到的噪声最小。采用语音质量感知评估对语音增强的效果进行评测,与传统的卡尔曼滤波语音增强算法相比,实验结果显示该算法提高了增强语音的质量。     

人耳听觉对声音相位感知能力的研究

1．序言 很多年来，人耳是否能够探测出声音信号的相位失真一直是一个存在争论的话题。很多研究也试图去探测人耳是否能感知出声音的相位变化，可以确定的是，人耳在特定的情况下对声音相位的变化是比较敏感的。     

基于时频注意力机制与U-Net的骨导语音鲁棒增强方法

近年来,基于神经网络的方法大量应用于骨导语音增强中。然而,由于骨导数据集样本较少,骨导语音高频部分缺失,不同说话人高频部分失真程度不同,神经网络难以有效学习骨导语音的频谱特征。因此,现有骨导语音增强模型对于未知说话人骨导语音数据集增强效果不佳、鲁棒性不强。为充分利用骨导语音的时频信息,引导模型关注骨导语音的低频部分特征,提出一种基于时频注意力机制和U-Net的骨导语音增强方法。该方法将时频注意力机制引入U-Net结构中,首先根据骨导语音时间、频率方向特征信息的重要程度自动为其分配权重,而后以加权后的骨导语音谱作为输入,对应的气导语音谱作为目标进入U-Net结构训练,最后利用训练完成的增强模型重构骨导语音全频带的语音。仿真实验与可视化分析结果表明,对比基线U-Net结构与其他注意力机制,该方法对于未知说话人骨导语音数据集能够取得更高的PESQ和STOI客观评价指标,增强语音更加清晰。     

基于LDPC码的数字音频水印算法研究

论文提出了一种基于低密度奇偶校验(LDPC)码的音频水印算法,对水印进行编码预处理后,采用时域去直流的方法并动态改变水印幅度嵌入水印,其中利用了人耳听觉系统的感知特性,把水印加在人耳感知极限下方。通过仿真实验结果表明,该算法具有较强的鲁棒性和不可感知性,而且在水印检测时不需要原始音频信号。     

基于听感知特性的噪声分析与防护

噪声是造成听力损伤的重要因素。针对噪声分析侧重研究噪声源的特性,较少考虑噪声防护需求的现状。从人耳听觉系统的感知特性出发,采用Gammatone分析滤波器组对声音在频域上进行非均匀多子带分解,通过耳谱图、子带能量及通道相关特性,定量计算噪声信号听感知特性,并提出了相应的噪声防护建议。从听感知特性出发分析噪声特征,进而设计的噪声防护方法是一种有效途径。     

骨导电话传输性能研究

介绍了目前市场上已有的骨导产品,通过对骨导基本原理的分析,在前人研究的基础上,着重研究了骨导电话接收方向的传输性能和试验方法,以促进骨导电话技术水平的进一步提高,更好的满足社会的无障碍需求,为社会公益事业作出贡献.     

Middle-ear structures contribute little to auditory perception of microwaves.

The contribution of the ossicles (middle-ear bones) to auditory perception of microwaves was evaluated by the brain-stem evoked response (BER). Amplitude and latency of BERs were recorded from guinea pigs that were stimulated at various intensities by acoustic pulses coupled to the auditory canal or via bone conduction, and by microwave pulses. Blocking of the external ear, middle-ear damping, and middle-ear destruction produced little change in the BERs that were elicited by microwave pulses. Results indicate that activity in the central auditory pathway as induced by pulsed microwaves only requires stimulation of the cochlea. Conduction of pressure waves through the bones of the calvarium appears to be the mechanism responsible in perception of pulsed microwaves.     

Ultrasonic assessment of human and bovine trabecular bone: acomparison study

A comparison study is reported on the ultrasonic assessment of human trabecular and bovine trabecular bone samples. Both ultrasonic velocity and ultrasonic attenuation were evaluated through a transmission insertion technique and correlated with bone mineral density as determined with single photon absorptiometry. For a 1 MHz ultrasonic transducer pair and the human cancellous bone samples the correlations were 0.91 and 0.89 between density and velocity and attenuation, respectively. For a 500 kHz ultrasonic transducer pair the correlations were 0.89 and 0.81 between density and velocity and attenuation, respectively. For the bovine bone samples, the correlations were 0.90 and -0.31 for the velocity and attenuation, respectively, for the 1 MHz transducer pair. For the 500 kHz transducers, the correlations were 0.85 and -0.17 for the velocity and attenuation, respectively. By combining both velocity and attenuation in a multivariate regression, an improvement was achieved in the estimation of bone density in the human samples for both the 500 kHz and 1 MHz transducer pairs. No significant improvement was achieved in the multivariate regressions for the bovine bone samples. In conclusion, the results indicate that ultrasonic measurements are in general highly correlated with bone mineral density in trabecular bone samples. This correlation is more consistent and strong in relatively low density human samples compared with the higher density bovine samples     

A comprehensive model of human ear for analysis of implantable hearing devices

A finite element (FE) model of the human ear including the ear canal, middle ear, and spiral cochlea was constructed from histological sections of human temporal bone. Multiphysics analysis of the acoustics, structure, and fluid coupling in the ear was conducted in the model. The viscoelastic material behavior was applied to the middle ear soft tissues based on dynamic measurements of tissues in our laboratory. The FE model was first validated using the experimental data obtained in human cadaver ears, and then used to investigate the efficiency of the forward and reverse mechanical driving with middle ear implant, and the passive vibration of basilar membrane (BM) with cochlear implant placed in the cochlear scala tympani. The middle ear transfer function and the cochlear function of the BM vibration were derived from the model. This comprehensive ear model provides a novel computational tool to visualize and compute the implantable hearing devices and surgical procedures.     

超声骨科换能器的组织负载特性研究

超声换能器的组织负载特性研究对提高其性能和安全性有重要的意义.选择新鲜的猪离体组织,利用动态信号分析仪的小信号及在线导纳测量系统的大信号对超声换能器的负载特性进行了研究.结果表明,当负载为松质骨、密质骨时,换能器谐振频率大于空载时的谐振频率,而负载为软组织(如肌肉、脂肪、皮等)时,换能器的谐振频率小于空载的谐振频率.换能器在小信号和大信号下的负载特性趋势基本相同.     

Development and application of ultrasonic surgical instruments

A new approach for designing ultrasonic surgical instruments (USI) is presented. These medical instruments convert an ultrasonic signal into a mechanical vibration by utilizing a magnetostrictive method and have been found to be very useful for various medical procedures. The implemented system consists of an ultrasonic generator, a transducer, and waveguide instruments. The generator produces a high-current ultrasonic signal. The transducer converts this signal into a mechanical vibration. By use of the waveguide instrument, the vibration can be propagated and amplified. This new type of USI possesses a comprehensive ability to stop bleeding, cut bone tissues, regulate frequency automatically, control temperature, etc. The results from animal experiments and from human clinical operations show that the developed USI has the advantages in various aspects over the conventional equipment     

基于毫米波雷达的人体生命体征感知方法

文中旨在探讨基于毫米波雷达技术的人体生命体征感知方法。毫米波雷达作为一种无线传感技术,在生命体征感知领域具有广泛的应用潜力。它能实现非侵入性、远距离、高分辨率的生命体征监测,包括呼吸、心跳、运动等关键参数的测量。文中详细介绍了毫米波雷达技术,探讨了其在生命体征感知中的优势,研究并设计了一种利用毫米波雷达进行人体生命体征感知算法的系统,旨在为毫米波雷达在生命体征感知领域的应用提供参考,为未来研究和创新提供有力支持。     

Charge carrier mobility in n-CdxHg1−x Te crystals subjected to dynamic ultrasonic stressing

The Hall mobility was studied in the n-Cd_xHg_1?x Te crystals subjected to dynamic ultrasonic stressing (W _US≤10⁴ W/m², f=5–7 MHz). It was found that, in field of the ultrasonic deformation, an increase in the carrier mobility in the impurity conduction region (T<120 K) and a decrease in the intrinsic conduction region (T>120 K) occurred in all tested samples. In this case, the magnitude of the sonic-stimulated variation in μ_H increases with decreasing structural perfection of a crystal. Different mechanisms of ultrasonic influence on μ_H with regard to scattering by optical phonons, ionized impurities, and alloy potential are analyzed, with the current flow conditions in the crystal taken into account. It is shown that, in the impurity conduction region, the main cause of the sonic-stimulated increase of the Hall mobility is the smoothing of the macroscopic intracrystalline potential that results from the inhomogeneity of the crystals. In the intrinsic conduction region, a decrease in mobility is caused by an increase in the intensity of scattering by the optical phonons.     

Haptic Perception,Mechanics, and Material Technologies for Virtual Reality

Emerging virtual and augmented reality technologies can transform human activities in myriad domains, lending tangible, embodied form to digital data, services, and information. Haptic technologies will play a critical role in enabling human to touch and interact with the contents of these virtual environments. The immense variety of skilled manual tasks that humans perform in real environments are only possible through the coordination of touch sensation, perception, and movement that together comprise the haptic modality. Consequently, many research groups are vigorously investigating haptic technologies for virtual reality. A longstanding research goal in this area has been to create haptic interfaces that allow their users to touch and feel plausibly realistic virtual objects. In this progress report, the perspective on this unresolved research challenge is shared, guided by the observation that no technologies can even approximately match the capabilities of the human sense of touch. Factors that have it challenging to engineer haptic technologies for virtual reality, including the extraordinary spatial and temporal tactile acuity of the skin, and the complex interplay between continuum mechanics, haptic perception, and interaction are identified. The perspective on how these challenges may be overcome through convergent research on haptic perception, mechanics, electronics, and material technologies is presented.