共查询到18条相似文献,搜索用时 93 毫秒
1.
2.
移频增音器在语言扩声系统中的应用 总被引:4,自引:2,他引:2
1 前言 在现代室内扩声技术中,用以衡量语言扩声系统质量的最重要的参数是增益量、清晰度和频率特性。而影响这三者最主要的又是声反馈。抑制声反馈最常用的方法有移频法、移相法、陷波法和压幅法。实践证明,其中移频法是最简单、最经济实用的。自1959年M.R施罗德提出用移频法解决声反馈的方法后,国内外市场便相继出现了各种专业移频器,且被广泛应用于各类音响工程,获得了良好的效果。后来由于国内最主要的移频器生产厂家停止生产,国外一些比较先进的声反馈抑制器乘机进入国内市场,但却因价格昂贵和操作复杂而使大多数需求者望而… 相似文献
3.
4.
应用串联陷波器实现反馈抑制时,自激频率的估计精度至关重要.基于多频带FFT的动态反馈抑制算法具有鲁棒性强、自激频率估计精度高、计算量适中等优点.算法选用具有32 bit浮点运算能力的SHAC系列DSP处理器ADSP21262实现,保证了算法计算精度.测试结果表明样机完全达到了仿真设计要求. 相似文献
5.
声反馈直接影响扩音系统的音质,严重时会破坏整个系统的稳定,在现场使用扩音系统时应采取必要的措施予以抑制。从声反馈的产生和危害入手,剖析了声反馈产生的原因,并重点从改变振幅条件和相位条件方面论述了对声反馈的抑制方法。 相似文献
6.
基于自适应波束形成的高维数据挖掘算法 总被引:1,自引:0,他引:1
提出一种基于自适应波束形成的高维声传感器网络数据挖掘算法.进行多通道声传感器网络信号的高维信息数据采集和相空间重组,进行信号模型构建,对高维数据信息流进行子空间降维和自适应陷波器降噪滤波处理,采用自适应波束形成方法进行数据的谱峰聚焦和特征提取,实现数据准确挖掘.仿真结果表明,采用该算法进行数据挖掘的准确检测概率较高,抗干扰性能较好,波束旁瓣得到有效抑制. 相似文献
7.
针对卫星导航接收机时域窄带干扰的有效抑制问题,本文首先给出二阶格型IIR陷波器参数设计方法,通过陷波带宽的定量调整,既可以有效抑制窄带干扰,又可以降低卫星信号的失真;其次推导了二阶IIR格型陷波器相关输出信干噪比改善因子的闭合表达式,该表达式相比干扰抑制后信干噪比的改善,更为直观地反映了陷波器对卫星导航信号的影响。理论分析和仿真实验,二阶格型IIR陷波器相关输出信干噪比改善因子与陷波器的带宽参数有关,而与陷波频率无关,且二阶格型IIR陷波器的性能优于最优线性预测Wiener滤波器、最优线性插值Wiener滤波器、五系数FIR滤波器以及二阶直接型IIR陷波器。 相似文献
8.
文中提出一种基于Welch谱估计的宽带通信窄带干扰抑制方法,并讨论了算法原理。该方法充分利用Welch功率谱估计的特点,使用加权系数陷波方法,克服了直接FFT零陷波法在频域抑制窄带干扰时信号畸变大的缺点。通过仿真分析,和直接周期图法相比,表明该方法有良好的误比特率性能。 相似文献
9.
10.
11.
12.
Acoustic feedback is an important factor that degrades the overall performance of hearing aids, and acoustic feedback cancellation has always been the research focus in the field of signal processing in hearing aids. The newly suggested adaptive projection subgradient method (APSM) for adaptive signal processing solves the problem of difficulty in finding the exact projection operator in the realization of affine projection by taking the subgradient projection hyperplane as the searching region for relaxed projection. This work applies APSM in the acoustic feedback cancellation system of hearing aids for the first time, and proposes a weighted adaptive projection subgradient method (WAPSM), which takes into consideration the exponential decay weight factor to incorporate the prior information of estimation system. The new method is compared with the traditional NLMS algorithm and APSM algorithm in simulation experiments. Incorporating the prior information of estimation system by setting the proper weighting matrix, WAPSM achieved notable improvements on the speed, stability and accuracy of the misalignment convergence. Numerical experiments demonstrate that the proposed algorithm is more robust for low SNR and real speech segment input than the traditional algorithms. 相似文献
13.
14.
15.
Digital notch filters are applied to remove or suppress the narrow-band interferences in digital signals, while preserving other components unchanged. Under the condition of the identical notch bandwidths, a novel design method is put forward in this paper to realize the adaptive notch filter with infinite-impulse response (IIR). Firstly, a specially simplified all-pass filter is introduced to construct an IIR non-adaptive notch filter, which serves as the core part in the adaptive one. Secondly, the criterion of least-mean-square (LMS) is applied to design the desired adaptive notch filter (ANF). The designed ANF can track and suppress multiple non-harmonic interference components simultaneously. Finally, the effectiveness and practicability of the proposed design method are verified by a set of experimental results. 相似文献
16.
17.
A continuous-time analog CMOS circuit with external feedback amplifiers implementing the least-mean square error adaptive learning algorithm has demonstrated a frequency of operation of 80 MHz, an adaptivity of 60 dB, a minimum notch width of 20 kHz, a minimum adapt time constant of 20 μs, and the simultaneous cancellation of two continuous-wave (CW) interferers. Auto-zeroing is used to cancel multiplier and integrator offsets. A fully monolithic adaptive filter circuit was also realized 相似文献
18.
Teleconferencing systems and hands-free mobile terminals use acoustic echo cancellation (AEC) for high-quality full-duplex speech communication. The problem of aliasing in subband AEC is addressed. Filter banks with implicit notch filtering are derived from cascaded power symmetric-infinite impulse response (CFS-IIR) filters. It is shown that adaptive filters used with these filter banks must be coupled via continuity constraints to reduce the aliasing in the residual echo. A continuity constrained NLMS algorithm is therefore proposed and evaluated 相似文献