水下噪声听觉属性的主观评价与分析

为探求人耳感知水下目标类型的声学因素,研究了水下噪声听觉属性空间的维度数及其各维度的物理解释.首先通过词汇聚类分析和问卷调查确定评价水下噪声听觉属性的汉语描述词,然后完成基于成对比较法和语义细分法的主观评价实验,获得听觉属性的不相似性矩阵及各样本在不同听觉属性下的主观评价分值.最后,利用多维尺度分析确定水下噪声听觉属性空间由五个维度组成,再利用主成分分析得到独立的五个主成分,进而利用相关系数和压力值确定五个主成分分别表示听觉属性空间的五个维度,根据各个主成分对应的汉语描述词所反映的听觉属性对其进行物理解释 关键词： 听觉属性 多维尺度分析 主成分分析     

不同测量对头相关传输函数的听觉影响

头相关传输函数(HRTF)是虚拟听觉重放的核心·目前,HRTF的实验室测量缺乏统一的规范。本文研究了不同测量对HRTF的听觉影响。首先提出了扩散场均衡的预处理方法,并对来自5个不同数据库的KEMAR假人的HRTF数据进行了扩散场均衡;然后,采用谱差异评估了不同数据库HRTF测量的频谱差异;最后,采用HRTF合成的虚拟声信号开展了一系列的主观听音实验,包括定位实验和区分实验·结果表明,扩散场均衡是一种有效的HRTF预处理方法,可以减小不同测量对HRTF频谱的影响;不同测量基本上不影响HRTF在12 kHz以下的定位效果,但对音色的影响较大,从而导致听觉上的可区分.      

节律性时间期待和空间期待对听觉目标辨别的影响

合理的推断和预期是加快辨别听觉目标的关键。通过听觉目标辨别的反应时任务,研究了听感知过程中节律性时间期待和空间期待对声音目标辨别的影响。实验中,听觉序列中各声音以规律或不规律的时间节奏、沿有序或随机的空间方位呈现,形成四种期待条件:时间和空间期待兼备、只有时间期待、只有空间期待和没有期待。被试对声音序列末尾随机呈现的听觉目标尽快做按键反应。结果发现:（1）节律性时间期待显著加快被试对目标声音的反应速度;（2）空间期待对目标辨别速度的促进作用仅在时间非规律条件下发生。可见,在辨别听觉目标时,听者优先使用时间期待,并在无有效时间预测信息时使用空间期待,以促成对声音目标的最优知觉加工。      

骨导超声听觉感知进展与研究*

骨导超声听觉感知是超声振动通过头骨传导产生听觉感知的一种特殊现象。本文首先介绍了骨导超声听觉感知研究领域的国内外发展现状,在此基础上设计了一套骨导超声听觉感知测试系统,并完成了系统的软、硬件平台实现。利用该系统,分别对听力正常和听力障碍被试者进行了主观测试,围绕单频超声感知效果及单频可听声、汉语语音由超声载波调制后的感知效果开展研究,比较了多种不同调制方式下的主观感知效果,并分析了空气传导声对实验结果的影响。     

基于人耳听觉模型的自动嗓音评估方法

在嗓音评估系统的长元音谐噪比分析中,针对传统方法在普通傅里叶变换域上进行谐波成分计算并且需要对样本进行人工选择切分的情况,提出了一种新谐噪比计算方法,能够自动切分出长元音中稳定部分,并采用了更贴近人耳听觉模型的时频分析办法,使对长元音的分析能够更稳定更贴近人耳主观听觉.同时由于没有人工干预,使得评估标准更加统一,结果更加客观. 关键词： 嗓音评估 听觉模型 长元音分析 谐噪比计算     

人耳辨识非语言声目标能力的实验研究

以主观听觉测试实验为手段,研究人耳听觉系统辨识能力与声音特性、评价主体训练程度及噪声干扰的关系.实验结果发现：人耳辨识声音能力主要由声信号的谱时结构决定,人耳对于谐音信号的辨识能力明显强于非谐音,对于稳态信号的辨识能力略强于瞬态信号;评价主体的训练可以提高辨识效果及准确性,但与声音特性密切相关;不同的噪声干扰对人耳目标辨识能力的影响主要取决于声音频谱结构;比对测听方式能提高非受训人员的辨识准确性,但不影响受训人员的辨识效果. 关键词： 听觉系统 主观听觉测试 目标辨识     

基于听觉感知的语音稀疏表示及压缩感知*

本文针对语音信号稀疏表示及压缩感知问题,将听觉感知引入稀疏系数筛选过程,用掩蔽阈值筛选重要系数,以得到更符合听觉感受的语音稀疏表示。通过对一帧浊音信号分别采用掩蔽阈值和能量阈值方法进行系数筛选对比实验,结果表明掩蔽阈值法具有更好的稀疏表示效果。为验证听觉感知对语音压缩感知性能的影响,与能量阈值法对照对测试语音进行压缩感知观测和重构,通过压缩比、信噪比、主观平均意见分等主客观指标评价其性能,结果表明,掩蔽阈值法可有效地提高压缩比且保证重构语音具有较高的主观听觉质量。     

听觉感知中的噪声特性语义描述及其分析

基于听觉感知的噪声语义描述是噪声声品质研究的基础性问题,已有研究未将语义描述与噪声来源、频谱特性以及产品运行状态等物理信息联系起来。该文分别针对飞机舱内噪声、车辆噪声和空气净化器噪声这3组典型噪声开展了主观评价实验,并通过多维尺度分析和主成分分析描述了3组噪声的语义空间,系统分析了不同类型噪声的描述词,同时解释了描述词与噪声物理属性之间的联系。研究发现：飞机舱内噪声、车辆噪声以及空气净化器噪声可以由4维、4维和3维语义空间进行描述;不同类型噪声在语义描述中具有共性与个性,3组噪声语义的主要维度均与嘈杂感相关,而噪声的个性描述词与其声源的物理属性密切相关;进行声品质建模及应用时,应同时考虑噪声共性和个性描述词对听觉感知的影响,采取有针对性的措施以提升产品声品质。该文从听觉感知的角度进行了噪声特性的语义描述和分析,研究结果可为产品声品质以及噪声控制研究提供帮助。     

基于听觉中枢模型的水下噪声音色表达与特性分析

为建立水下噪声音色特征的定量表达以用于目标识别, 本文将主观评价实验获得的 4个本质音色维度得分与声音的听觉中枢响应建立联系, 得到音色的偏最小二乘回归模型, 并基于回归系数对每个维度进行物理分析. 为验证该方法的有效性, 本文提取大量音色描述符作为自变量进行对比, 结果表明听觉中枢模型预测能力有一定优势. 同时发现, 前 3个本质音色维度可分别由高频能量比例、谱平坦程度和时域连续性描述, 而第4 维度则无法与任何声学特征建立联系. 关键词： 本质音色 听觉中枢模型 偏最小二乘回归 音色描述符     

汉语语境下的车辆噪声听觉属性评价与分析

研究了等响度车辆噪声听觉属性的空间维度及其汉语表述.首先通过问卷调查确定评价车辆噪声听觉属性的汉语描述词,然后完成基于成对比较法和语义细分法的主观评价实验,获得听觉属性的不相似度矩阵及描述词的等级顺序.最后,利用多维尺度分析和主成分分析法得到独立的用中文表达的车辆噪声听觉属性,结果表明:对于等响度的车辆噪声,其听觉属性可以用三个维度表示,分别用"粗糙"、"刺耳"和"起伏"描述.     

Impact of unilateral hearing loss on sound localization

The impact of unilateral hearing loss on the localization of horizontal plane sound sources ipsilateral and contralateral to the side of the unimpaired ear was examined. Normal-hearing listeners judged the direction of six loudspeakers, separated by 30° and arrayed frontally or laterally on the right side with the right or left ear occluded. The benefit of massed practice over three sequential days was assessed. For the frontal loudspeaker array, azimuthal discrimination on the occluded side was poor but only 30% of sounds were perceived to come from the unoccluded side. For the right lateral array, when the ipsilateral ear was unoccluded, front and back were rarely confused. Accuracy mainly decreased for speakers close to the midline axis, front and back. When the contralateral ear was unoccluded responses were biased toward the rearmost speaker. Practice did not improve performance. The findings were discussed within the context of military operations. They support the need for job-specific hearing standards.     

A field study to assess the effects of wearing hearing protectors on the perception of warning sounds in an industrial environment

A field study has been performed which assessed the effectiveness of two warning sounds under realistic factory conditions. The thirty subjects were press operators who were involved in their regular work activities during the course of the experiment. The noise levels at their work stations were in the range 85 to 95 dB(A). The warning sound, plus four other irrelevant sounds, each at one of five different intensities, were presented via a loudspeaker in random order and at random time intervals (mean inter-stimulus interval, 30 s; range, 10 to 50 s). The influence of the factors hearing level and age of the subjects and use of hearing protection were investigated.The results showed significant differences between the intentional and incidental warning sounds investigated. Whilst the perception of the intentional horn warning sound was unaffected by the hearing sensitivity of the subjects and the wearing of hearing protectors, these two factors had a significant effect on the perception, as a warning, of the clinking sound of metal components. Subjects classified as having a substantial hearing loss perceived, on average, 18 percent fewer clinking sounds than those subjects with normal hearing or a mild hearing loss and, when wearing hearing protectors, the subjects overall perceived, on average, 9 percent fewer clinks. It is of note that the results of the field study differ from those of earlier laboratory-based experiments in finding that the distinctive intentional warning sound was not entirely reliable as a warning, even at levels substantially above its masked threshold, and in observing more than double the adverse effect of wearing hearing protection.     

Musical background not associated with self-perceived hearing performance or speech perception in postlingual cochlear-implant users

In normal-hearing listeners, musical background has been observed to change the sound representation in the auditory system and produce enhanced performance in some speech perception tests. Based on these observations, it has been hypothesized that musical background can influence sound and speech perception, and as an extension also the quality of life, by cochlear-implant users. To test this hypothesis, this study explored musical background [using the Dutch Musical Background Questionnaire (DMBQ)], and self-perceived sound and speech perception and quality of life [using the Nijmegen Cochlear Implant Questionnaire (NCIQ) and the Speech Spatial and Qualities of Hearing Scale (SSQ)] in 98 postlingually deafened adult cochlear-implant recipients. In addition to self-perceived measures, speech perception scores (percentage of phonemes recognized in words presented in quiet) were obtained from patient records. The self-perceived hearing performance was associated with the objective speech perception. Forty-one respondents (44% of 94 respondents) indicated some form of formal musical training. Fifteen respondents (18% of 83 respondents) judged themselves as having musical training, experience, and knowledge. No association was observed between musical background (quantified by DMBQ), and self-perceived hearing-related performance or quality of life (quantified by NCIQ and SSQ), or speech perception in quiet.     

Perception of complex sounds in budgerigars (Melopsittacus undulatus) with temporary hearing loss

Songbirds and parrots deafened as nestlings fail to develop normal vocalizations, while birds deafened as adults show a gradual deterioration in the quality and precision of vocal production. Beyond this, little is known about the effect of hearing loss on the perception of vocalizations. Here, we induced temporary hearing loss in budgerigars with kanamycin and tested several aspects of the hearing, including the perception of complex, species-specific vocalizations. The ability of these birds to discriminate among acoustically distinct vocalizations was not impaired but the ability to make fine-grain discriminations among acoustically similar vocalizations was affected, even weeks after the basilar papilla had been repopulated with new hair cells. Interestingly, these birds were initially unable to recognize previously familiar contact calls in a classification task-suggesting that previously familiar vocalizations sounded unfamiliar with new hair cells. Eventually, in spite of slightly elevated absolute thresholds, the performance of birds on discrimination and perceptual recognition of vocalizations tasks returned to original levels. Thus, even though vocalizations may initially sound different with new hair cells, there are only minimal long-term effects of temporary hearing loss on auditory perception, recognition of species-specific vocalizations, or other aspects of acoustic communication in these birds.     

Evaluation of the risk of noise-induced hearing loss among unscreened male industrial workers

Variability in background risk and distribution of various risk factors for hearing loss may explain some of the diversity in excess risk of noise-induced hearing loss (NIHL). This paper examines the impact of various risk factors on excess risk estimates of NIHL using data from the 1968-1972 NIOSH Occupational Noise and Hearing Survey (ONHS). Previous analyses of a subset of these data focused on 1172 highly "screened" workers. In the current analysis, an additional 894 white males (609 noise-exposed and 285 controls), who were excluded for various reasons (i.e., nonoccupational noise exposure, otologic or medical conditions affecting hearing, prior occupational noise exposure) have been added 2066) to assess excess risk of noise-induced material impairment in an unscreened population. Data are analyzed by age, duration of exposure, and sound level (8-h TWA) for four different definitions of noise-induced hearing impairment, defined as the binaural pure-tone average (PTA) hearing threshold level greater than 25 dB for the following frequencies: (a) 1-4 kHz (PTA1234), (b) 1-3 kHz (PTA123), (c) 0.5, 1, and 2 kHz (PTA512), and (d) 3, 4, and 6 kHz (PTA346). Results indicate that populations with higher background risks of hearing loss may show lower excess risks attributable to noise relative to highly screened populations. Estimates of lifetime excess risk of hearing impairment were found to be significantly different between screened and unscreened population for noise levels greater than 90 dBA. Predicted age-related risk of material hearing impairment in the ONHS unscreened population was similar to that predicted from Annex B and C of ANSI S3.44 for ages less than 60 years. Results underscore the importance of understanding differential risk patterns for hearing loss and the use of appropriate reference (control) populations when evaluating risk of noise-induced hearing impairment among contemporary industrial populations.     

基于Cool Edit Pro 2.0 的人耳听阈曲线测定实验

利用数字音乐编辑软件Cool Edit Pro 2.0,设计了人耳听阈曲线测定实验.该实验使用计算机即可进行,除添置1台声级计(共用)定标外,不再需其他仪器.实验中信号频率可任意设定,信号强度动态范围可达80 dB,分贝值读数精度可达0.1 dB,可利用同台计算机进行数据处理、作图等.     

Distribution of risk factors for hearing loss: implications for evaluating risk of occupational noise-induced hearing loss

This paper presents an analysis of hearing threshold levels among 2066 white male workers employed in various U.S. industries studied in the 1968-72 NIOSH Occupational Noise and Hearing Survey (ONHS). The distribution of hearing threshold levels (HTL) is examined in relation to various risk factors (age, prior occupational noise, medical conditions) for hearing loss among a population of noise exposed and control (low noise-exposed) industrial workers. Previous analyses of a subset of these data from the ONHS focused on 1172 highly "screened" workers. An additional 894 male workers (609 noise-exposed and 285 controls), who were excluded for various reasons (i.e., nonoccupational noise exposure, otologic or medical conditions affecting hearing, prior occupational noise exposure) have been added to examine hearing loss in an unscreened population. Data are analyzed by age, duration of exposure, and sound level (8-h TWA) by individual test frequency. Results indicate that hearing threshold levels are higher among unscreened noise-exposed and control workers relative to screened workers. Analysis of risk factors such as nonoccupational noise exposure, medical conditions, and type of industry among unscreened controls indicated that these factors were not significantly associated with increased mean HTLs or risk of material impairment over and above what is expected due to age. Age-specific mean hearing threshold levels (and percentiles of the distribution) among the unscreened ONHS control population may be used as a comparison population of low-noise exposed white male industrial workers for evaluating the effectiveness of hearing conservation programs for workers less than 55 years of age. To make valid inferences regarding occupational noise-induced hearing loss, it is important to use hearing data from reference (control) populations that are similar with respect to the degree of subject screening, type of work force (blue vs white collar), and the distribution of other risk factors for hearing loss.     

Compression and expansion of the temporal envelope: evaluation of speech intelligibility and sound quality.

Sensorineural hearing loss is accompanied by loudness recruitment, a steeper-than-normal rise of perceived loudness with presentation level. To compensate for this abnormality, amplitude compression is often applied (e.g., in a hearing aid). Alternatively, since speech intelligibility has been modeled as the perception of fast energy fluctuations, enlarging these (by means of expansion) may improve speech intelligibility. Still, even if these signal-processing techniques prove useful in terms of speech intelligibility, practical application might be hindered by unacceptably low sound quality. Therefore, both speech intelligibility and sound quality were evaluated for syllabic compression and expansion of the temporal envelope. Speech intelligibility was evaluated with an adaptive procedure, based on short everyday sentences either in noise or with a competing speaker. Sound quality was measured by means of a rating-scale procedure, for both speech and music. In a systematic setup, both the ratio of compression or expansion and the number of independent processing bands were varied. Individual hearing thresholds were compensated for by a listener-specific filter and amplification. Both listeners with normal hearing and listeners with sensorineural hearing impairment participated as paid volunteers. The results show that, on average, both compression and expansion fail to show better speech intelligibility or sound quality than linear amplification.     

Localization ability with bimodal hearing aids and bilateral cochlear implants

After successful cochlear implantation in one ear, some patients continue to use a hearing aid at the contralateral ear. They report an improved reception of speech, especially in noise, as well as a better perception of music when the hearing aid and cochlear implant are used in this bimodal combination. Some individuals in this bimodal patient group also report the impression of an improved localization ability. Similar experiences are reported by the group of bilateral cochlear implantees. In this study, a survey of 11 bimodally and 4 bilaterally equipped cochlear implant users was carried out to assess localization ability. Individuals in the bimodal implant group were all provided with the same type of hearing aid in the opposite ear, and subjects in the bilateral implant group used cochlear implants of the same manufacturer on each ear. Subjects adjusted the spot of a computer-controlled laser-pointer to the perceived direction of sound incidence in the frontal horizontal plane by rotating a trackball. Two subjects of the bimodal group who had substantial residual hearing showed localization ability in the bimodal configuration, whereas using each single device only the subject with better residual hearing was able to discriminate the side of sound origin. Five other subjects with more pronounced hearing loss displayed an ability for side discrimination through the use of bimodal aids, while four of them were already able to discriminate the side with a single device. Of the bilateral cochlear implant group one subject showed localization accuracy close to that of normal hearing subjects. This subject was also able to discriminate the side of sound origin using the first implanted device alone. The other three bilaterally equipped subjects showed limited localization ability using both devices. Among them one subject demonstrated a side-discrimination ability using only the first implanted device.     

Noise-induced hearing damage caused by metabolic exhaustion: a mathematical model

A mathematical model for noise-induced hearing loss is based on the assumption that hair cells are damaged, temporarily or permanently, by metabolic exhaustion, and that the number of damaged hair cells and the hearing loss are monotonically increasing functions of an energy deficiency. The purpose of the model is to focus on the influence of sound intensity, exposure duration, and temporal pattern of the sound exposure on the noise-induced hearing loss from long-duration exposures. The model is restricted to the range of sound levels where metabolic exhaustion probably is the main reason for the hair cell damage. Only exposures with similar frequency spectra and producing moderate hearing losses are considered; frequency dependence is not discussed.