数字传声器测试

介绍了数字传声器的基本原理和结构及数字信号的编码方式。针对数字传声器测试中遇到的困难提出了一种解决方案,通过信号处理模块进行D／A转换后得到模拟信号给电声测试系统进行测试并显示各相关参数．使数字传声器试验生产和常规生产的测试更加方便。     

数字传声器系统的设计

简述了数字传声器系统的两部分：数据发送端和远程控制端的功能，硬件电路的设计，以及数据发送端和远程控制端之间的通信协议。并对比了数字传声器系统与模拟传声器两者各自的特点。     

数字传声器原理与应用

介绍了数字传声器的基本原理、结构以及声学、电气性能.阐述了数字传声器在产品使用中的基本要求.展望了市场应用前景.     

数字传声器技术

从信号流、动态范围和噪声、信号传输、远程控制,同步等方面,系统全面地介绍了数字传声器技术。尤其是对于集成于数字传声器内部的ADC设计做了较为详细的讨论。     

微型数字传声器技术与发展

介绍了微型驻极体(ECM)与微机电(MEMS)数字传声器的技术原理及在消费数码领域的应用,综述了微型数字传声器技术的发展过程与市场分析。     

DIS新型枪形传声器

DIS现推出一款新型枪形传声器,扩大了DCS6000数字会议系统的产品阵营。DISGM6622是一款具有宽频微型电容传声器的枪形传声器,尤其适用于需要高保真扩声、专业录音和电视制作等应用、拾音要求非常严苛的场合,如市政厅、法院和国会等。     

舒音2.4G数字笔型无线传声器

舒音2.4G数字笔型无线传声器功能简介如下:(1)内置蓝牙数字识别系统,操作简单,铝合金管体笔型无线发射机轻巧方便,广泛适用于教学、演讲以及会议等场合。(2)使用方便,只需将笔型无线传声器     

超指向性数字传声器

引言今天的电视广播已进入高图像质量和高音质的时代,也已进入有临场感的节目制作时期。但在体育等中继转播中,当摄相机和传声器远离摄取对象时,以前曾尝试过图像用望远透镜(lens)摄录,而声音用超指向传声器(Gun—Mi-crophone)或抛物面传声器(Parabola—Micro-phone)拾取,但直到目前尚得不到好的结果。目前开始的AM立体声广播,一般的无线广播,也都希望有不断提高的声音质量。下面介绍松下开发的能清楚地拾取远方声音的采用数字处理的超指向性数字传声器。     

TS-8807/TS-8807A

8807手持传声器专为KTV工程安装、专业演唱、家庭娱乐等场所设计,8807领夹传声器适合于学校演讲,娱乐节目互动等场所使用。DPLL数字锁相环多信道频率合成技术在     

舒音2．4G数学笔型无线传声器

舒音2．4G数字笔型无线传声器功能简介如下：（1）内置蓝牙数字识别系统,操作简单,铝合金管体笔型无线发射机轻巧方便,广泛适用于教学、演讲以及会议等场合。（2）使用方便,只需将笔型无线传声器电源开关打开靠近接收机天线5m内,笔型无线传声器自动寻找频率。（3）发射机自带增益调节,可自由控制发射距离,20～40m内不掉线。（4）铝合金管体,轻巧,咪头设两档增益开关,HI档适合放置于桌面、衣袋和挂置胸前;LO档可直接当手持式传声器使用。     

Development of an Optimized Feature Extraction Algorithm for Throat Signal Analysis

In this paper, we present a speech recognition system using a throat microphone. The use of this kind of microphone minimizes the impact of environmental noise. Due to the absence of high frequencies and the partial loss of formant frequencies, previous systems using throat microphones have shown a lower recognition rate than systems which use standard microphones. To develop a high performance automatic speech recognition (ASR) system using only a throat microphone, we propose two methods. First, based on Korean phonological feature theory and a detailed throat signal analysis, we show that it is possible to develop an ASR system using only a throat microphone, and propose conditions of the feature extraction algorithm. Second, we optimize the zero‐crossing with peak amplitude (ZCPA) algorithm to guarantee the high performance of the ASR system using only a throat microphone. For ZCPA optimization, we propose an intensification of the formant frequencies and a selection of cochlear filters. Experimental results show that this system yields a performance improvement of about 4% and a reduction in time complexity of 25% when compared to the performance of a standard ZCPA algorithm on throat microphone signals.     

两种抛物面形状的指向性传声器的比较

传声器系统指向性的实现主要有两种途径：一是通过特殊的声结构,二是通过传声器阵列。比较了一个带有抛物面形状反射面的传声器系统和与抛物面开口面积相同的圆形传声器阵列的差异。分别使用Kirchhoff-Helmholtz积分方程和阵列理论对这两种传声器系统的性能进行研究。数值模拟的结果表明,抛物面反射式传声器系统在高频时具有更高的灵敏度,其指向性通常也好于圆形传声器阵列。     

Single Ping-multiple measurements: sonar bearing angle estimation using spatiotemporal frequency filters

Presented is a mixed-signal full-custom VLSI chip designed to receive sonar return signals from an ultrasonic microphone array, and extract input bearing angles of the incoming signals. Processing utilizes simple low-power analog spatiotemporal bandpass filters to extract wavefront velocity across the array, which translates to input bearing angle. Processing uses phase information of array signals, not onset or offset of ultrasonic burst. With such synchronous processing, multiple angle readings from different returns of the same ultrasonic transmit burst are possible. Compatible microphone arrays are compact in size-test array has a total baseline of 26.5 mm. In a test with ultrasonic beacon 65 cm from a microphone array, angular precision of 1/spl deg/ was demonstrated in most instances in the range -60/spl deg/ to 60/spl deg/. Applications include sonar localization of remote objects, sonar imaging, and improved interference rejection between objects within the field of view of the sensor microphones. The chip was fabricated on a standard 3M2P CMOS process with a 0.5-/spl mu/m feature size.     

传声器的检测和认证

从传声器的工作原理入手,详细介绍了传声器被干扰的现象及产生的原因,从设计上提出了避免电磁兼容问题的方法,并分析了国内传声器检测和认证的现状,提出了实行传声器电磁兼容自愿认证的建议,以供广大传声器制造厂商和认证机构、检测机构参考.     

基于传声器阵列的语音增强技术

介绍了几种传声器阵列语音增强算法,包括固定波束形成、自适应波束形成、传声器阵后维纳滤波,并对各算法的性能和特点进行了分析。同时,对近几年基于传声器阵的语音增强技术的发展趋势进行了简单介绍。     

AWA6653型测试传声器自动测试系统

随着社会对声学测试的需求不断提高,声学测量仪器所需要的传声器质量要求严格,频率范围拓宽,产量大幅增加,传统的手工测量或电平记录仪记录方法已不能满足测试要求。在多年前开发的一款传声器自动测试系统的基础上,改进了测试装置,提高了传声器频响测试上限频率,同时增加了多种功能,如传声器校准、开路灵敏度计算、失真测量等。通过测试、该自动测试系统大大提高了传声器的测试效率。     

电容传声器阻抗变换器的设计

电容传声器几乎是所有各类传声器中规格品种最多的。介绍了各类电容传声器阻抗变换器的线路原理。包括最简单的ECM阻抗变换器,JFET设计的共漏、共源阻抗变换器,电子管阻抗变换器,RF射频阻抗变换器等,特别介绍了目前在很多国外电容传声器阻抗变换器设计中出现的新设计：变形的跟随器设计。     

A novel microphone preamplifier for use in hearing aids

A novel design for a microphone preamplifier for application in hearing aids is presented. The amplifier operates at a supply voltage of 1-1.3 V, the current drain is 70µA. The maximum sound level allowed is more than 105 dB SPL, with a typical noise level of 28 dB SPL. Instead of the usual voltage sensing, current sensing of the microphone is used. The amplifier consists of a fully balanced charge-to-current amplifier with no external components required. A semicustom version of the design has been integrated in a standard BIMOS process.     

Optimal Design of Nearfield Wideband Beamformers Robust Against Errors in Microphone Array Characteristics

Nearfield wideband beamformers for microphone arrays have wide applications, such as hands-free telephony, hearing aids, and speech input devices to computers. The existing design approaches for nearfield wideband beamformers are highly sensitive to errors in microphone array characteristics, i.e., microphone gain, phase, and position errors, as well as sound speed errors. In this paper, a robust design approach for nearfield wideband beamformers for microphone arrays is proposed. The robust nearfield wideband beamformers are designed based on the minimax criterion with the worst case performance optimization. The design problems can be formulated as second-order cone programming and be solved efficiently using the well-established polynomial time interior-point methods. Several interesting properties of the robust nearfield wideband beamformers are derived. Numerical examples are given to demonstrate the efficacy of the proposed beamformers in the presence of errors in microphone array characteristics.     

Design of broadband beamformers robust against gain and phase errors in the microphone array characteristics

Fixed broadband beamformers using small-size microphone arrays are known to be highly sensitive to errors in the microphone array characteristics. The paper describes two design procedures for designing broadband beamformers with an arbitrary spatial directivity pattern, which are robust against gain and phase errors in the microphone array characteristics. The first design procedure optimizes the mean performance of the broadband beamformer and requires knowledge of the gain and the phase probability density functions, whereas the second design procedure optimizes the worst-case performance by using a minimax criterion. Simulations with a small-size microphone array show the performance improvement that can be obtained by using a robust broadband beamformer design procedure.