主观音质评价能力培养与音质评价流程探讨

针对一款电声产品,需要进行主观音质评价.如何对产品进行主观音质评价,以及如何提升工程师主观音质评价能力至关重要.基于工作实践的积累和学习,给出提升音质评价能力的思路和方法,并结合产品主观评价的流程和方法,给出思路和建议.     

试论广播电视作品声音质量的主观评价方法

广播电视作品声音质量的评价方法有客观和主观两种。本文论述了主观音质评价方法的重要性，讨论了有关的问题，并就音质评价术语与客观电声指标之间的关系作简单的说明     

声级校准方式在成对评价听音试验中的影响

探讨了扬声器主观音质评价试验中成对评价法的声级校准方式对试验结果的影响。对声级校准的两种主要方法:强度指标校准和响度指标校准进行了讨论。通过一次成对评价的扬声器听音试验,对使用不同声级校准方式下的评价结果进行分析讨论。结果表明,扬声器的主观音质评价试验中,成对评价法的声级校准方式对试验结果影响显著。     

室内声学的进展

对室内声学的几个方面：吸声降噪、室内声场理论、厅堂音质在物理、心理和生理声学及音质主观评价等方面的研究进展进行了综述和讨论。     

"声音质量主观评价用节目源标准样品"的论述

结合标准样品的基本概念,对节目源标准样品进行理论分析,并对几个主要的特性进行了介绍.电声产品和电声产品的声音质量(音质)是个心理量,它需要通过音质主观评价来获得结果,并用评价尺度来表示它的大小.同任何一个检测结果一样,音质主观评价结果同样必须具有溯源性和离散性这两个属性.标准样品的主要特性包括:溯源性、均匀性及稳定性、测量不确定度等.有证节目源国家标准样品的成功研制,对促进音质主观评价事业的技术发展和提高国内音响产品的音质水平具有重大意义.     

用“模糊二阶综合评判方法”对音质主观评价的研究

对节目音质的主观评价应采用什么方法研究?评价术语有哪些?一直是电声界讨论的问题。用传统的数理统计方法去处理音质评价问题,有时会很难办。为此,有人提出用模糊数学方法对电声器件的音质进行研究。但提出的模型在实际应用中,有许多不足之处,且各术语的权重是人为确定的,有很大的主观性。因此,本文在论述音乐节目的音质主观评价具有模糊性的基础上,用模糊数学的方法对音质评价结果进行了分析。提出音质主观评价应采用“模糊二阶综合评判”的方法。并用模糊数学的计算方法确定了各术语的权重。对评价术语的选择是参考了大量国内外文献并结合节目录音的特点而定的。听音实验的声音样本是国内、外生产的唱片中选的各种体裁的音乐片段。实验者为受过专门训练的音乐教师,音响工程师和音响导演。     

二级模糊综合评判在音质主观评价中的应用研究(续)

五、二级模糊综合评判在音质评价中的应用 1.因素类的选择在对收音机、录音机音质的主观评价中,有关音质的信息是通过音质评价节目反映出来的。IEC543号“主观听音试验指南”和IEC268—13“扬声器听音试验”中对音质评价节目内容作了规定。我国制定的《收音机、录音机听音试验》标准(报批稿)中规定的节目内容有:     

基于E1接口感知语音质量测试设备的实现方案

语音音质评价从主体上可分为主观评价和客观评价两种。由于音质好坏最终取决于人的主观感受,所以在语音系统中主要采用主观评价的方法。但是这种方法费时费力,同时受到测试条件和测试人员主观因素的影响,降低了测试结果的可靠性。针对上述缺点,设计了一种客观评价语音音质的测试设备实现方案,该测试设备基于E1接口,采用ITU-T P.862 PESQ算法模型。     

电声系统的声音质量及评价

１音质的主观评价音质主观评价是一项相当复杂的过程，涉及到人的心理学、生理学和专业人员的经验素养等。音质主观评价是直接与人耳的听觉感受联系在一起的，在听音过程中，评价人员根据自己主观的听音感觉，用一些特定的专用词汇来形象化地表达自己听后的感觉。因此，对听评人员来说要做好音质的主观评价工作，必须掌握以下十方面的知识：①声音的物理特性；②人耳的听觉特性；③声音的动态范围；④声压级的大小与音质的关系；⑤频率响应特性与音质评价的关系；⑥信号畸变与音质的关系；⑦信号延迟、混响与音质的关系；⑧噪声与音质的关系…     

广播节目声音质量主观评估探讨

广播节目声音质量的评价方法有客观和主观两种.客观测试可借鉴的方法较多,但主观测试可借鉴的不多,因此本文在论述广播节目主观音质评价的重要性和必要性之后,主要阐述如何更科学、有效并具有可操作性的主观测试方法,分析了影响音频节目主观感受的主要因素,并探讨了改善和保持广播节目高质量音质的工作措施.     

高频电子电路中的耦合系数及耦合电容

在高频电路中,有时用到电容耦合回路,其调谐特性和频率特性与耦合系数直接相关.因此,耦合系数的确定与耦合电容的选择是该电路设计中的一个重要问题.在现有高频电路教材中,一般对电容耦合回路耦合系数的确定与耦合电容的选择这一重要问题未作深入讨论.为此,本文归纳总结了电容耦合回路设计中,耦合系数的确定与耦合电容的选择这个重要问题.     

Loss-Free Balancing Circuit for Series Connection of Electrolytic Capacitors Using an Auxiliary Switch-Mode Power Supply

Most of today's power converters such as three-phase variable-speed drives, uninterruptible power systems, welding converters, and telecom and server power supplies are based on voltage-source converters equipped with bulky dc-link electrolytic capacitors. To be able to handle full dc bus voltage, the dc bus capacitor is arranged as series-connected electrolytic capacitors rated at lower voltage. An electrolytic capacitor, however, is not an ideal capacitor. It has significant leakage current that strongly depends on the capacitor temperature, voltage, and ageing conditions. To compensate large dispersion of the leakage current and ensure acceptable sharing of the total dc bus voltage among the series-connected capacitors, a passive balancing circuit is often used. Drawbacks of the ordinary passive balancing circuit, such as size, significant losses, and standby consumption are discussed in this paper. An active loss-free balancing circuit, which utilizes an auxiliary switch-mode power supply (SMPS) to equalize the capacitor voltages, is proposed. The capacitors midpoint (MP) is connected to the SMPS via two devices; namely a current injection device and a compensation device. The current injection device injects current into the capacitors MP, while the compensation device sinks the difference between the capacitor leakage currents and the injected current. As a result, the capacitor voltages are controlled and maintained in the desired ratio. The proposed balancing technique is theoretically analyzed and experimentally verified on a laboratory setup. The results are presented and discussed.      

Measurements of leakage currents and the capacitance of the storagecapacitor in a single DRAM cell

Methods of measuring leakage currents and the capacitance of the storage capacitor in a single DRAM cell have been developed for correlation with the electrode shape of the capacitor. In the circuit used for these measurements, the plate electrode of the storage capacitor is connected to the gate of the MOSFET which amplifies the voltage variations of the storage capacitor during the measurements. Here, only a conventional transistor parameter analyzer and a capacitance meter are required for the measurements. For the capacitance measurement, the linear region characteristics of the MOSFET are used to simplify the analysis. For the leakage current measurement, however, the subthreshold region characteristics of the MOSFET are used to enhance the accuracy of the measurement. The results show that the very low leakage currents (down to below 0.1 fA) and the capacitance (37.5 fF) of the storage capacitor can be measured accurately. Further, the leakage current-voltage characteristics of the storage capacitor are discussed by comparing with those of a large area planar capacitor whose structure is the same as the storage capacitor     

一种带电容网络的窄带陶瓷滤波器

采用一种新的设计方法来研制一种小体积的窄带陶瓷滤波器。此种方法仅采用一种标准的压电振子 ,并与一定的电容网络相结合 ,就可实现通常由串、并联两种振子构成的滤波特性。本文探讨了这种压电振子的特性以及电容网络的选择与近似计算方法。     

Listening as a Missing Dimension in Engineering Education: Implications for Sustainable Community Development Efforts

Although listening is valued in engineering education literature, it is conspicuously absent from engineering curricula. Using interview data, data from published literature, reflective instructional experiences, and the intersection of those three data sources, this study investigates two primary issues: (1) engineering students' sources of resistance to listening instruction in a sustainable community development initiative, and (2) benefits from such instruction. Findings feature a proposed theory of contextual listening and suggest that sources of resistance include the paucity of listening instruction in the engineering curriculum and curricular components that may devalue listening. Benefits of a listening intervention are described, and implications are discussed.      

Estimation and compensation of process-induced variations in capacitors for improved reliability in integrated circuits

This paper describes a method for the estimation of capacitor process variations in integrated circuits and for the subsequent compensation of such variations through a calibration scheme that exploits a variable capacitor bank. An architecture for the calibration circuit is proposed, and various problems that arise during implementation are discussed. The design consists of an oscillator whose output frequency is inversely proportional to the capacitor value and simple state machine for measurement of capacitor process variations. The design of optimum capacitor bank is described together with the adequate tuning plan. The circuit is fabricated and verified in 130 nm RF CMOS process and can be easily scaled to sub-100-nm technologies.     

时域有限差分法分析平板电容的宽频特性

用时域有限差分法分析了平板电容的宽频特性，讨论了电容集总特性与频率的关系，其结果对于ＭＥＳＦＥＴ功率器件内匹配研究工作具有实用价值。     

电子镇流器用低损耗铝电解电容器

根据电子镇流器对铝电解电容器性能的要求,开发了高电导率、低漏电流的电解液。研制出ｔｇδ为常规品一半的铝电解电容器。在带负载的耐久性试验中通过了１０００ｈ,１００℃考核。从容量变化率考虑,低损耗铝电解电容器适用于电子镇流器线路。     

橡胶塞的老化和电容器寿命

铝电解电容器橡胶塞的质量是影响寿命的关键因素。根据电容器的工作特点,研究了对橡胶塞用橡胶的要求,指出橡胶塞的老化机理是热氧老化。对比了各种橡胶的结构和性能特点,对国内现有EPDM和IIR的105℃系列的橡胶塞进行了试验研究,指出开发长寿命橡胶塞应该注意的问题。