To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dyn...To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dynamic range compression （WDRC） methods are alternately employed according to the dynamic range of the band-passed signal and the hearing range （HR） of the patient. To further reduce the distortion caused by the WDRC and improve the output signal to noise ratio （SNR） under noise conditions, an adaptive adjustment of the compression ratio is presented. Experimental results demonstrate that the output SNR of the proposed method in babble noise is improved by at least 1.73 dB compared to the WDRC compensation method, and the average speech intelligibility is improved by 6.0% and 5. 7%, respectively, compared to the linear and WDRC compensation methods.展开更多
设计一款音频响度控制器,该响度控制器支持对多声道AES3数字音频和数字分量串行接口(Serial Digital Interface,SDI)嵌入音频进行响度监测控制。该响度控制器根据设定的不同类型的音频信号目标响度值,由响度测量计算方法逆推,对音频信...设计一款音频响度控制器,该响度控制器支持对多声道AES3数字音频和数字分量串行接口(Serial Digital Interface,SDI)嵌入音频进行响度监测控制。该响度控制器根据设定的不同类型的音频信号目标响度值,由响度测量计算方法逆推,对音频信号进行频域均衡,按频率划分为几个子带,再经过限幅器输出符合目标响度的音频信号,解决了音频响度控制问题,使音频响度可测可控。在节目制播和传输过程中,通过合理有效地控制节目音频响度,提高用户的响度舒适度。展开更多
A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parame...A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parameters as used when determining the equal-loudness-level contours of the former ISO standard. However, as an additional main idea, a loudness summation rule has been proposed in the study. Moreover, the loudness expressions have been normalised to give the same values for people who have a similar sense of hearing. It has also been found that the loudness expressions include basically two different weightings. The first weighting is a conservative frequency weighting in the domain of sound pressure level, and the second weighting consists of coefficients applied to the weighted sound pressure levels. The latter have the greatest effect on the very low-frequency range. Finally, the paper includes a new way to use the A-weighting which takes into account the compressed character of the equal-loudness-level contours at the low frequency range. This method remarkably transforms the character of the A-weighting as a measure for low-frequency environmental noise.展开更多
The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values def...The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values defining equal-loudness-level contours that are not consistent with the chosen loudness function type. Serious mathematical and acoustical discrepancies have also been found that result in constant terms having an unnecessarily high numerical accuracy and a flawed phon definition, which leads to an erroneous loudness level representation. Therefore an extensive treatment of the logarithmic calculations (phon) of a loudness function is performed in this study. Finally, the author concludes that it would be desirable for the discrepancies in the standard (shown in the study) to be taken into account and corrected before publishing a new version of the standard.展开更多
基金The National Natural Science Foundation of China(No.61301219,61375028,61273266)the Natural Science Foundation of Jiangsu Province(No.BK20130241)+1 种基金the Fundamental Research Funds for the Central Universities(No.2242013K30010)the Science and Technology Program of Nantong(No.BK2014002)
文摘To alleviate the conflict between audibility and distortion in the conventional loudness compensation method, an adaptive multichannel loudness compensation method is proposed for hearing aids. The linear and wide dynamic range compression （WDRC） methods are alternately employed according to the dynamic range of the band-passed signal and the hearing range （HR） of the patient. To further reduce the distortion caused by the WDRC and improve the output signal to noise ratio （SNR） under noise conditions, an adaptive adjustment of the compression ratio is presented. Experimental results demonstrate that the output SNR of the proposed method in babble noise is improved by at least 1.73 dB compared to the WDRC compensation method, and the average speech intelligibility is improved by 6.0% and 5. 7%, respectively, compared to the linear and WDRC compensation methods.
文摘设计一款音频响度控制器,该响度控制器支持对多声道AES3数字音频和数字分量串行接口(Serial Digital Interface,SDI)嵌入音频进行响度监测控制。该响度控制器根据设定的不同类型的音频信号目标响度值,由响度测量计算方法逆推,对音频信号进行频域均衡,按频率划分为几个子带,再经过限幅器输出符合目标响度的音频信号,解决了音频响度控制问题,使音频响度可测可控。在节目制播和传输过程中,通过合理有效地控制节目音频响度,提高用户的响度舒适度。
文摘A stationary loudness model has been built up on the basis of the former ISO 226: 1987 concerning equal-loudness-level contours. The loudness and loudness level expressions derived in the study include the same parameters as used when determining the equal-loudness-level contours of the former ISO standard. However, as an additional main idea, a loudness summation rule has been proposed in the study. Moreover, the loudness expressions have been normalised to give the same values for people who have a similar sense of hearing. It has also been found that the loudness expressions include basically two different weightings. The first weighting is a conservative frequency weighting in the domain of sound pressure level, and the second weighting consists of coefficients applied to the weighted sound pressure levels. The latter have the greatest effect on the very low-frequency range. Finally, the paper includes a new way to use the A-weighting which takes into account the compressed character of the equal-loudness-level contours at the low frequency range. This method remarkably transforms the character of the A-weighting as a measure for low-frequency environmental noise.
文摘The recent Standard ISO 226 concerning equal-loudness-level contours has been critically analysed. As a result, it is shown that the fitting and smoothing processes applied in the standard lead to parameter values defining equal-loudness-level contours that are not consistent with the chosen loudness function type. Serious mathematical and acoustical discrepancies have also been found that result in constant terms having an unnecessarily high numerical accuracy and a flawed phon definition, which leads to an erroneous loudness level representation. Therefore an extensive treatment of the logarithmic calculations (phon) of a loudness function is performed in this study. Finally, the author concludes that it would be desirable for the discrepancies in the standard (shown in the study) to be taken into account and corrected before publishing a new version of the standard.
文摘为了提高有源噪声控制系统的降噪效果,提出了基于经验模态分解(empirical mode decomposition,EMD)和响度的控制系统。该系统首先采用EMD方法对噪声源进行自适应分解,并对分解后的各个固有模态函数(intrinsic mode functionI,MF)分量的响度进行计算,然后根据各个分量的响度大小进行残差滤波器的设计。与基于A计权曲线设计的残差滤波器相比,该方法所设计滤波器能更好地抑制响度较小的信号频率成分。对有源噪声控制系统的降噪效果进行了仿真,结果表明,所提出的控制系统比传统滤波-X LMS(filtered-X least mean square)方法和采用基于A计权残差滤波器的系统降噪效果更好。
