Yuta Tamai, Kazuyuki Matsumoto, S. Hiryu, Kohta I. Kobayasi
An extra-cochlear stimulation system has been investigated as a less invasive alternative to conventional cochlear implant; however, the system is used primarily as a speech-reading aid. The purpose of this study was to develop a speech encoding scheme for the extra-cochlear stimulation system to convey intelligible speech. A click-modulated speech sound (CMS) was created as a simulation of the extra-cochlear stimulation system. The CMS is a repetitive click with a repetition rate similar to the formant frequency transition of an original sound. Seven native Japanese speakers with normal hearing participated in the experiment. After listening to the CMS, synthesized from low familiarity Japanese words, the subjects reported their perceptions. The results showed that the rates of correctly identified vowels and consonants were significantly higher than those of the control stimulus, suggesting that the CMS can generate at least partially intelligible vowel and consonant perceptions. In all, the speech encoding scheme could be applied to the extra-cochlear stimulation system to restore speech perception.
{"title":"Speech Encoding Scheme for the Extra-Cochlear Pulsed Electrical Stimulation System","authors":"Yuta Tamai, Kazuyuki Matsumoto, S. Hiryu, Kohta I. Kobayasi","doi":"10.4236/OJA.2018.83005","DOIUrl":"https://doi.org/10.4236/OJA.2018.83005","url":null,"abstract":"An extra-cochlear stimulation system has been investigated as a less invasive alternative to conventional cochlear implant; however, the system is used primarily as a speech-reading aid. The purpose of this study was to develop a speech encoding scheme for the extra-cochlear stimulation system to convey intelligible speech. A click-modulated speech sound (CMS) was created as a simulation of the extra-cochlear stimulation system. The CMS is a repetitive click with a repetition rate similar to the formant frequency transition of an original sound. Seven native Japanese speakers with normal hearing participated in the experiment. After listening to the CMS, synthesized from low familiarity Japanese words, the subjects reported their perceptions. The results showed that the rates of correctly identified vowels and consonants were significantly higher than those of the control stimulus, suggesting that the CMS can generate at least partially intelligible vowel and consonant perceptions. In all, the speech encoding scheme could be applied to the extra-cochlear stimulation system to restore speech perception.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"8 1","pages":"52-60"},"PeriodicalIF":0.0,"publicationDate":"2018-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42210171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling signals and compared them with the original input signal. The factors under investigation in this experiment included: wood type, wood moisture content (MC), input signal frequencies, signal travelling distance and wood condition (wood with/without cracks). The experiment findings demonstrated that higher input signal frequencies results in higher attenuation of acoustic emissions (AE) travelling through the wood. The results also indicate that: wood type, MC, the signal’s travelling distance, and the orientation of the travelling signal, compared to the wood’s grain direction, affected the signal propagation.
{"title":"The Effect of Wood Condition on Sound Wave Propagation","authors":"A. El-Hadad, G. Brodie, B. Ahmed","doi":"10.4236/oja.2018.83004","DOIUrl":"https://doi.org/10.4236/oja.2018.83004","url":null,"abstract":"This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling signals and compared them with the original input signal. The factors under investigation in this experiment included: wood type, wood moisture content (MC), input signal frequencies, signal travelling distance and wood condition (wood with/without cracks). The experiment findings demonstrated that higher input signal frequencies results in higher attenuation of acoustic emissions (AE) travelling through the wood. The results also indicate that: wood type, MC, the signal’s travelling distance, and the orientation of the travelling signal, compared to the wood’s grain direction, affected the signal propagation.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"8 1","pages":"37-51"},"PeriodicalIF":0.0,"publicationDate":"2018-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46830099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-28DOI: 10.12677/OJAV.2018.62005
郑伟光, 林泽宇, 唐荣江
{"title":"Optimization and Analysis of Acoustic Impedance of Duct Wall Based on Virtual.Lab Acoustics","authors":"郑伟光, 林泽宇, 唐荣江","doi":"10.12677/OJAV.2018.62005","DOIUrl":"https://doi.org/10.12677/OJAV.2018.62005","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"06 1","pages":"36-45"},"PeriodicalIF":0.0,"publicationDate":"2018-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66178066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Detection and localization of acoustic events in an environment are important to protect the military and civilian installations. While there are finite paths of wave propagation in simple or low reverberant environments, in complex environments (e.g. a complex urban environment) obstacles such as terrain or buildings introduce multipath propagations, reflections and diffractions which make source localization challenging. Therefore, numeric results of simulated models (simplified and Fort Benning urban models) of 3D complex environments can highly help in real applications. Some of the conventional beamformer algorithms have been used in order to localize point sound source. Analyzing results shows that MRCB beamformer has better performance than others in this issue and its accuracy superiority is more than 3 m in simplified urban model and 5 m in Fort Benning urban model with respect to the SOC. Moreover, due to possible uncertainties between the numerical model and the actual environment such as squall effect, temperature gradient etc., sensitivity of the beamformers to temperature gradient is investigated which shows higher robustness of SOC beamformer than the MRCB beamformer. According to the results, due to gradient temperature uncertainty the accuracy degradation of the SOC is about 1m while in MRCB it alters from 0.5 m to 20 m approximately at all SNRs. COMSOL Multiphysics has been used to numerically simulate the environment of wave propagation.
{"title":"Detection of Point Sound Source Using Beamforming Technique in Complex Environments","authors":"Navid Nassaji, Masoume Shafieian","doi":"10.4236/OJA.2018.82003","DOIUrl":"https://doi.org/10.4236/OJA.2018.82003","url":null,"abstract":"Detection and localization of acoustic events in an environment are important to protect the military and civilian installations. While there are finite paths of wave propagation in simple or low reverberant environments, in complex environments (e.g. a complex urban environment) obstacles such as terrain or buildings introduce multipath propagations, reflections and diffractions which make source localization challenging. Therefore, numeric results of simulated models (simplified and Fort Benning urban models) of 3D complex environments can highly help in real applications. Some of the conventional beamformer algorithms have been used in order to localize point sound source. Analyzing results shows that MRCB beamformer has better performance than others in this issue and its accuracy superiority is more than 3 m in simplified urban model and 5 m in Fort Benning urban model with respect to the SOC. Moreover, due to possible uncertainties between the numerical model and the actual environment such as squall effect, temperature gradient etc., sensitivity of the beamformers to temperature gradient is investigated which shows higher robustness of SOC beamformer than the MRCB beamformer. According to the results, due to gradient temperature uncertainty the accuracy degradation of the SOC is about 1m while in MRCB it alters from 0.5 m to 20 m approximately at all SNRs. COMSOL Multiphysics has been used to numerically simulate the environment of wave propagation.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"23-35"},"PeriodicalIF":0.0,"publicationDate":"2018-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44865663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In real life, when a noise problem occurs, it is important to identify the cause and measure the noise of the source, since it may affect human beings or other constructions due to vibration generated from noise, so it is necessary to determine the noise related to a specific source like a machine in the presence of other sources which is a very important approach in noise control engineering. In this article a full experiment was executed to measure the sound pressure levels of various sources (stationary and non-stationary), in both an anechoic chamber and a non-ideal noisy environment. The sound pressure level was extracted for different sources and compared for both ideal and non-ideal environment. The results showed that acoustical free field of the space is the best field to do measurements to avoid reflection, on the other hand the difference between the source and the background should be more than 3 dB to get better results.
{"title":"Measurement of Sound Pressure Levels in Anechoic Chamber and a Noisy Environment Experimentally","authors":"M. Zubi","doi":"10.4236/oja.2018.82002","DOIUrl":"https://doi.org/10.4236/oja.2018.82002","url":null,"abstract":"In real life, when a noise problem occurs, it is important to identify the cause and measure the noise of the source, since it may affect human beings or other constructions due to vibration generated from noise, so it is necessary to determine the noise related to a specific source like a machine in the presence of other sources which is a very important approach in noise control engineering. In this article a full experiment was executed to measure the sound pressure levels of various sources (stationary and non-stationary), in both an anechoic chamber and a non-ideal noisy environment. The sound pressure level was extracted for different sources and compared for both ideal and non-ideal environment. The results showed that acoustical free field of the space is the best field to do measurements to avoid reflection, on the other hand the difference between the source and the background should be more than 3 dB to get better results.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"8 1","pages":"13-22"},"PeriodicalIF":0.0,"publicationDate":"2018-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43433305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The availability of ideal conditions like anechoic chamber to characterize some sound parameters, like sound intensity and sound power necessities the determination of free field and cut off frequency measurements. In this article, full experiment was executed at Wayne State University (Detroit-Michigan), to determine the cut off frequency in all directions; the obtained results showed that the free field can be determined for a specified space. So other tests can take place in this space avoiding regions where reflections and consequently noise can be found. Upon these results tests related to noise abatement in vehicles can be done in such environment.
{"title":"An Experimental Method to Determine the Cut-Off Frequency of an Acoustical Free Field in a Non-Ideal Environment","authors":"M. Zubi","doi":"10.4236/oja.2018.81001","DOIUrl":"https://doi.org/10.4236/oja.2018.81001","url":null,"abstract":"The availability of ideal conditions like anechoic chamber to characterize some sound parameters, like sound intensity and sound power necessities the determination of free field and cut off frequency measurements. In this article, full experiment was executed at Wayne State University (Detroit-Michigan), to determine the cut off frequency in all directions; the obtained results showed that the free field can be determined for a specified space. So other tests can take place in this space avoiding regions where reflections and consequently noise can be found. Upon these results tests related to noise abatement in vehicles can be done in such environment.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2018-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70558100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-01-15DOI: 10.12677/OJAV.2018.61001
戴峥, 汪胡根, 乔飞, 李峰, 钱艳园, 王俊生
采用穿孔板共振吸声结构用于变电站噪声治理，根据变电站噪声频率分布特性设计了共振吸声结构参数，并对共振结构吸声系数进行了数值仿真，得到其吸声谱在低频具有相对较大的吸声系数。对设计的穿孔板共振吸声结构进行了工程实验，利用设计的软件得到变电站的可听噪声倍频A计权声压级。分析了噪声治理前后的不同频带噪声的变化特性，测试结果表明所采用穿孔板共振吸声结构具有较好频率选择吸声特性，该结构大幅度地降低了变电站中的低频噪声，使变电站的噪声得到有效的控制。 This paper discusses the use of perforated plate resonant sound absorption structure for substation noise control. Based on the noise distribution characteristics of the substation, the resonant sound absorption structure parameters are designed, and the sound absorption coefficient of the resonant structure is numerically simulated. It is shown that the structure has a relatively large sound absorption coefficient at low frequency. Experiments are conducted to verify the perforated plate resonant sound absorption structure and a software is designed to obtain the substation audible noise frequency A weighted sound pressure level. The results show that the resonant sound absorption structure of the perforated plate has better frequency selection sound absorption characteristics, which greatly reduces the low frequency noise in the substation and makes the noise of the substation get effective control.
The perforated plate resonant sound absorption structure is used for noise control in substations. The parameters of the resonant sound absorption structure are designed based on the frequency distribution characteristics of substation noise, and the absorption coefficient of the resonant structure is numerically simulated. It is found that its absorption spectrum has a relatively large absorption coefficient at low frequencies. Engineering experiments were conducted on the designed perforated plate resonant sound absorption structure, and the audible noise octave A-weighted sound pressure level of the substation was obtained using the designed software. The variation characteristics of noise in different frequency bands before and after noise control were analyzed. The test results showed that the perforated plate resonant sound absorption structure used has good frequency selective sound absorption characteristics, which greatly reduces low-frequency noise in the substation and effectively controls the noise in the substation. This paper discusses the use of preempted plate resonant sound absorption structure for substation noise control Based on the noise distribution characteristics of the substation, the resonant sound absorption structure parameters are designed, and the sound absorption coefficient of the resonant structure is numerically simulated It is shown that the structure has a relatively large sound absorption coefficient at low frequency Experiences are conducted to verify the advanced plate resonant sound absorption structure and a software is designed to retain the substation audible noise frequency A weighted sound pressure level The results show that the resonant sound absorption structure of the advanced plate has better frequency selection sound absorption characteristics, which greatly reduces the low frequency noise in the substation and makes the noise of the substation get effective control
{"title":"变电站降噪方法研究 Research on Acoustic Noise Reduction Methods for Substation","authors":"戴峥, 汪胡根, 乔飞, 李峰, 钱艳园, 王俊生","doi":"10.12677/OJAV.2018.61001","DOIUrl":"https://doi.org/10.12677/OJAV.2018.61001","url":null,"abstract":"采用穿孔板共振吸声结构用于变电站噪声治理，根据变电站噪声频率分布特性设计了共振吸声结构参数，并对共振结构吸声系数进行了数值仿真，得到其吸声谱在低频具有相对较大的吸声系数。对设计的穿孔板共振吸声结构进行了工程实验，利用设计的软件得到变电站的可听噪声倍频A计权声压级。分析了噪声治理前后的不同频带噪声的变化特性，测试结果表明所采用穿孔板共振吸声结构具有较好频率选择吸声特性，该结构大幅度地降低了变电站中的低频噪声，使变电站的噪声得到有效的控制。 This paper discusses the use of perforated plate resonant sound absorption structure for substation noise control. Based on the noise distribution characteristics of the substation, the resonant sound absorption structure parameters are designed, and the sound absorption coefficient of the resonant structure is numerically simulated. It is shown that the structure has a relatively large sound absorption coefficient at low frequency. Experiments are conducted to verify the perforated plate resonant sound absorption structure and a software is designed to obtain the substation audible noise frequency A weighted sound pressure level. The results show that the resonant sound absorption structure of the perforated plate has better frequency selection sound absorption characteristics, which greatly reduces the low frequency noise in the substation and makes the noise of the substation get effective control.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"06 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45338520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-01-01DOI: 10.12677/OJAV.2018.63009
严 志刚
{"title":"Study and Progress of Nonlinear Dynamics of Semi-Active Suspension System Vibration for Railway High-Speed Train","authors":"严 志刚","doi":"10.12677/OJAV.2018.63009","DOIUrl":"https://doi.org/10.12677/OJAV.2018.63009","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"06 1","pages":"71-78"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66178336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：