共查询到18条相似文献,搜索用时 140 毫秒
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《声学学报:英文版》2015,(6)
提出了一种吸顶式传声器阵列阵元坐标的标定方法。针对在混响声场中,时延估计算法性能严重下降从而导致在标定传声器阵元坐标时产生较大误差的问题,提出了利用脉冲声源作为标定声源,并且截取脉冲源直达声的方法来抑制混响声场的影响,提高传声器阵元坐标标定的精度。建立了阵元坐标标定的误差分析模型,并以白噪声和脉冲声源作为标定声源进行数据仿真和对比分析。仿真结果表明,使用脉冲声源作为标定声源能有效地抑制混响声场的影响,获得传声器阵列阵元的准确坐标。同时,在封闭的房间内建立起孔径为3.5 m、64阵元的螺旋状吸顶传声器阵列进行了实验研究,实验结果验证了本文提出方法的有效性。 相似文献
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提出了一种吸顶式传声器阵列阵元坐标的标定方法。针对在混响声场中,时延估计算法性能严重下降从而导致在标定传声器阵元坐标时产生较大误差的问题,提出了利用脉冲声源作为标定声源,并且截取脉冲源直达声的方法来抑制混响声场的影响,提高传声器阵元坐标标定的精度。建立了阵元坐标标定的误差分析模型,并以白噪声和脉冲声源作为标定声源进行数据仿真和对比分析。仿真结果表明,使用脉冲声源作为标定声源能有效地抑制混响声场的影响,获得传声器阵列阵元的准确坐标。同时,在封闭的房间内建立起孔径为3.5 m、64阵元的螺旋状吸顶传声器阵列进行了实验研究,实验结果验证了本文提出方法的有效性。 相似文献
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论室内声场 总被引:2,自引:0,他引:2
室内声场的经典理论中只有简正波(混响声)而缺乏直达声,这不符合实际。实际上声源具有二重作用,或说声源的作用有两项功能。一是声源按自由空间辐射声波,只要不遇到室的墙壁、边界,就不会改变。自由辐射达到任一边界后,就逐渐失去其球面波的特性,成为被反射为壁面上的一系列小波,时间、空间、方向都是无规分布,但是小波的来源都可推到声源上,这是第二功能。这些小波继续传播、反射,最后形成室内允许的驻波,这些就是简正波了。所以声源既是直达声波的声源,又是室内驻波的声源。据此可改正室内声波方程,解出室内声场,包括直达声波和简正波,并求得直达声和混响声的关系。声衰变过程的特性。声衰变中,稳态声中的直达声不会立刻停止,其后果值得注意。PACS数: 43.20,43.55 相似文献
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对于线性单频混响声场的统计特性的研究人们曾做了许多工作,建立了均方根声压和平均声能密度统计分布理论。本文在此基础上推导出声压级统计分布函数,并把处理方法推广到混响室内在强大声源激发下的非线性单频混响声场,求得各谐波声场和总声场的统计分布函数。本文实验采用数字测量技术,对混响声场进行了大量的测量,得到的实验结果与理论符合良好。 相似文献
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厅堂音质中的响度评价 总被引:4,自引:0,他引:4
厅堂音质评价的各项指标中,响度是最重要和最基本的内容之一。但由于长期来缺乏合适的参量,因此迄今无法在完工后的厅堂中去测量这项指标,当然也难以在设计阶段对此参量进行估算.不少人常把仅仅适用于稳态声源和混响场的声场估算法(即以直达声加上混响声)作为厅堂内各处总声强的评价,无论从音质设计和现场测量来看,显然很不合适。近年Lehmann提出以声强指数G(Starkemass)(dB)作为评价参量是一个好的建议。但根据我们的研究结果来看,鉴于早期反射声对响度起主导作用,因此厅堂内各处的声强指数应取50ms(语言)和80ms(音乐)的早期反射声积分值更符合实际,。以代替t从0积分到∞的评价方法。因此G(50ms)和G(80ms)将分别用于评价厅堂内对语言和音乐的响度评价参量。 相似文献
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Suppression of reverberation distortions of a receiver signal using the water tank transfer function
The paper considers a method for suppressing the reverberant distortions of an underwater sound receiver signal during receiver calibration in a laboratory water tank. The method is based on using the water tank transfer function, which is a complex frequency-dependent coefficient that establishes, for the point of signal reception, the relation between the sound pressures in the reverberant sound field of the water tank and in the free sound field. The procedure for experimentally obtaining the water tank transfer function is considered. Examples of suppressing reverberant distortions during noise and pulse sound reception are presented. 相似文献
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The reciprocity measurement theory in anomalous reverberant sound fields was investigated.An improved method Was proposed due to the interrelated errors.The source volume velocity Was corrected by spatial average of measurement results and evaluation of the reverberant sound field influence on acoustic energy density.The result was validated in underwater experiment,corrected reciprocity measurement results were almost the same as direct measurement results.It indicates that reverberant sound field does not affect the validitv of the principle,but influences the obtainment of source volume velocity,then influences the measurement of transfer functions with the principle.The proposed method is simple and effective in anomalous reverberant sound fields.The study mav be valuable for the applications which are based on the principle. 相似文献
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The binaural room impulse responses (BRIRs) can be applied to 3-D sound field reconstruction, virtual reality, noise control, et al. Because the BRIRs are non-minimum phase functions, it is difficult to find the exact inverse functions of the BRIRs, especially when there are two or more sources in a reverberant space. In this work, a method was proposed to find the inverse functions of BRIRs with two sound sources in a reverberant space. The concept of time delays and the method of weighted least squares were used to find the causal, however, approximate inverse functions. The accuracy of the inverse functions was first evaluated objectively by a dummy head system. The result shows that the distortion due to crosstalk and room reverberation can be improved by 16∼18 dB. The inverse functions were also verified subjectively by 20 students. The result of subjective evaluation also shows that the inverse functions can be used successfully to reduce the crosstalk effect and the room reverberation. 相似文献
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扩散声场会在反射边界附近形成干涉图样,研究方法包括平面波模型、简正模态分析、渐进模态分析等,但仅适用于尺度远大于声波波长的矩形声腔。提出一种预测扩散声场在非规则刚性壁面结构附近形成的干涉图样的数值方法,表明结构附近“受挡”声压的互谱矩阵取决于:(1)假定该结构在自由空间中振动辐射声音时其表面法向振速到表面及场点声压的边界元系数矩阵;(2)假定结构置于自由空间中且表面刚性时,点声源辐射声波入射到结构表面上产生的散射声场的边界元系数矩阵;(3)扩散声场均方声压。仿真表明,该途径预测的干涉图样与理论值完全吻合。该预测方法还可用于混响环境下声源附近直达声压均方值的空间分布估计,为混响环境下设备的声源定位提供帮助。 相似文献
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Adaptive beamformers have been proposed as noise reduction schemes for conventional hearing aids and cochlear implants. A method to predict the amount of noise reduction that can be achieved by a two-microphone adaptive beamformer is presented. The prediction is based on a model of the acoustic environment in which the presence of one acoustic target-signal source and one acoustic noise source in a reverberant enclosure is assumed. The acoustic field is sampled using two omnidirectional microphones mounted close to the ears of a user. The model takes eleven different parameters into account, including reverberation time and size of the room, directionality of the acoustic sources, and design parameters of the beamformer itself, including length of the adaptive filter and delay in the target signal path. An approximation to predict the achievable signal-to-noise improvement based on the model is presented. Potential applications as well as limitations of the proposed prediction method are discussed and a FORTRAN subroutine to predict the achievable signal-to-noise improvement is provided. Experimental verification of the predictions is provided in a companion paper [J. Acoust. Soc. Am. 109, 1134 (2001)]. 相似文献
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Simulating the response of multiple microphones to a single acoustic source in a reverberant room 总被引:2,自引:0,他引:2
P M Peterson 《The Journal of the Acoustical Society of America》1986,80(5):1527-1529
A method is presented for simulating the impulse response between an acoustic source and multiple microphones in a reverberant room. The method is similar to the image method described by Allen and Berkley [J. Acoust. Soc. Am. 65, 943-950 (1979)] but includes modifications to simulate received echo arrival time accurately. The essential modification is to represent each received echo as a low-pass-filtered impulse at the correct arrival time. Using this "low-pass impulse" method, reverberant rooms can be simulated with sufficient accuracy to investigate multiple-microphone systems that are sensitive to interchannel phase. 相似文献
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Al Munawir Azma Putra Iwan Prasetiyo Wan Mohd Farid Wan Mohamad Safarudin Herawan 《声与振动》2021,55(3):203-219
Statistical Energy Analysis (SEA) is a well-known method to analyze the flow of acoustic and vibration energy in a complex structure. This study investigates the application of the corrected SEA model in a non-reverberant acoustic space where the direct field component from the sound source dominates the total sound field rather than a diffuse field in a reverberant space which the classical SEA model assumption is based on. A corrected SEA model is proposed where the direct field component in the energy is removed and the power injected in the subsystem considers only the remaining power after the loss at first reflection. Measurement was conducted in a box divided into two rooms separated by a partition with an opening where the condition of reverberant and non-reverberant can conveniently be controlled. In the case of a non-reverberant space where acoustic material was installed inside the wall of the experimental box, the signals are corrected by eliminating the direct field component in the measured impulse response. Using the corrected SEA model, comparison of the coupling loss factor (CLF) and damping loss factor (DLF) with the theory shows good agreement. 相似文献
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Ihlefeld A Shinn-Cunningham BG 《The Journal of the Acoustical Society of America》2011,130(1):324-333
Two experiments explored how frequency content impacts sound localization for sounds containing reverberant energy. Virtual sound sources from thirteen lateral angles and four distances were simulated in the frontal horizontal plane using binaural room impulse responses measured in an everyday office. Experiment 1 compared localization judgments for one-octave-wide noise centered at either 750 Hz (low) or 6000 Hz (high). For both band-limited noises, perceived lateral angle varied monotonically with source angle. For frontal sources, perceived locations were similar for low- and high-frequency noise; however, for lateral sources, localization was less accurate for low-frequency noise than for high-frequency noise. With increasing source distance, judgments of both noises became more biased toward the median plane, an effect that was greater for low-frequency noise than for high-frequency noise. In Experiment 2, simultaneous presentation of low- and high-frequency noises yielded performance that was less accurate than that for high-frequency noise, but equal to or better than for low-frequency noise. Results suggest that listeners perceptually weight low-frequency information heavily, even in reverberant conditions where high-frequency stimuli are localized more accurately. These findings show that listeners do not always optimally adjust how localization cues are integrated over frequency in reverberant settings. 相似文献