“鸡尾酒会”环境中的知觉线索的去掩蔽作用

在有多人同时说话的嘈杂环境中,为什么具有正常听力的人能在一定的程度上听懂目标语句？研究这个著名的“鸡尾酒会”问题的一个新进展是将干扰言语的作用区分出了能量掩蔽和信息掩蔽两种成分。与发生在外周系统的能量掩蔽不同,信息掩蔽发生在心理层次并受到认知过程的调节。因此,主观空间分离、与目标语句节奏相关的视觉信号以及对目标语句某些特征的熟悉程度等知觉线索都具有去掩蔽作用。考察可减少信息掩蔽的知觉线索的交互作用及其高级认知调节是今后重要的研究内容     

听觉信息掩蔽的亚成分：基于行为和脑成像研究的证明

听觉掩蔽的机制是解决嘈杂声学环境下对特定目标声音进行加工, 即“鸡尾酒会”问题的关键。听觉掩蔽可以分为能量掩蔽和信息掩蔽两种类型。前者是因为目标和掩蔽声音在听觉外周在时间和频率上的重叠所造成的, 而后者被认为是掩蔽声音在听觉中枢和目标声音竞争加工资源所造成的。长久以来, 信息掩蔽一直被当作一种单一成分的现象, 这一概念框架已经成为制约对其机制进行深入研究的一个瓶颈。信息掩蔽中至少包含有知觉信息掩蔽和认知信息掩蔽两种亚成分, 它们源于不同的中枢机制。多个说话人声音掩蔽的条件下, 总体掩蔽量是能量掩蔽、知觉信息掩蔽和认知信息掩蔽等成分总和的结果。操纵掩蔽和目标声音的知觉空间分离、掩蔽声音的可懂度以及掩蔽和目标声音的知觉相似度, 可以实现对两种信息掩蔽亚成分的双重分离。应用功能性核磁共振成像技术可以发现两者有不同的神经机制。     

言语的情绪韵律和情绪语义对听觉去信息掩蔽的作用

言语的情绪信息(情绪性韵律和情绪性语义)具有去听觉掩蔽的作用, 但其去掩蔽的具体机制还不清楚。本研究通过2个实验, 采用主观空间分离范式, 通过操纵掩蔽声类型的方式, 分别探究言语的情绪韵律和情绪语义去信息掩蔽的机制。结果发现, 情绪韵律在知觉信息掩蔽或者在知觉、认知双重信息掩蔽下, 均具有去掩蔽的作用。情绪语义在知觉信息掩蔽下不具有去掩蔽的作用, 但在知觉、认知双重信息掩蔽下具有去掩蔽的作用。这些结果表明, 言语的情绪韵律和情绪语义有着不同的去掩蔽机制。情绪韵律能够优先吸引听者更多的注意, 可以克服掩蔽声音在知觉上造成的干扰, 但对掩蔽声音在内容上的干扰作用很小。言语的情绪语义能够优先获取听者更多的认知加工资源, 具有去认知信息掩蔽的作用, 但不具有去知觉信息掩蔽的作用。     

掩蔽刺激对目标识别加工的作用：来自fNIRS的证据

信息掩蔽刺激(如随机字母群)对字母视觉搜索的干扰大于能量掩蔽刺激(如将字母群像素随机化后的散点), 但相应的中枢机理还不清楚。本研究采用记录脑代谢激活模式的功能性近红外光学脑成像技术(fNIRS), 考察年轻成年被试分别在字母掩蔽、字母碎片掩蔽、像素掩蔽条件下判断上、下、左、右四个目标字母是否相同时的大脑皮层氧合血红蛋白浓度的变化。结果显示, 依字母、字母碎片、随机散点掩蔽条件顺序, 被试的搜索任务成绩显著递增, 而顶-枕皮层的激活范围与程度显著递减, 表明信息掩蔽较匹配的能量掩蔽对视觉搜索有更大的干扰作用, 并在初级和联合视觉皮层引发更大的激活。在字母碎片掩蔽条件下, 视觉初级皮层部分区域的激活水平与搜索行为绩效的相关显著, 而在字母掩蔽条件下, 视觉联合皮层部分区域的激活水平与搜索行为绩效的相关显著。这进一步说明信息掩蔽中的字母掩蔽和字母碎片掩蔽的掩蔽作用在大脑皮层上所造成的加工负载存在差异。     

Emotionally conditioning the target-speech voice enhances recognition of the target speech under “cocktail-party” listening conditions

Under a noisy “cocktail-party” listening condition with multiple people talking, listeners can use various perceptual/cognitive unmasking cues to improve recognition of the target speech against informational speech-on-speech masking. One potential unmasking cue is the emotion expressed in a speech voice, by means of certain acoustical features. However, it was unclear whether emotionally conditioning a target-speech voice that has none of the typical acoustical features of emotions (i.e., an emotionally neutral voice) can be used by listeners for enhancing target-speech recognition under speech-on-speech masking conditions. In this study we examined the recognition of target speech against a two-talker speech masker both before and after the emotionally neutral target voice was paired with a loud female screaming sound that has a marked negative emotional valence. The results showed that recognition of the target speech (especially the first keyword in a target sentence) was significantly improved by emotionally conditioning the target speaker’s voice. Moreover, the emotional unmasking effect was independent of the unmasking effect of the perceived spatial separation between the target speech and the masker. Also, (skin conductance) electrodermal responses became stronger after emotional learning when the target speech and masker were perceptually co-located, suggesting an increase of listening efforts when the target speech was informationally masked. These results indicate that emotionally conditioning the target speaker’s voice does not change the acoustical parameters of the target-speech stimuli, but the emotionally conditioned vocal features can be used as cues for unmasking target speech.     

噪音背景对二语语音感知的影响

日常言语交流常常会遇到各种噪音的干扰。研究表明, 噪音所产生的能量掩蔽和信息掩蔽会给语音感知带来较大影响。在感知地道的二语语音时, 二语者在各种噪音条件下所受干扰通常比母语者更大, 其表现随噪音类型、水平和目标音位特征的不同而变化; 同时, 二语者的感知也存在较大个体差异, 这是多种因素影响的结果。在噪音下感知带有各种外国腔的二语口音时, 母语者的表现差于其对地道母语语音的感知; 二语经历贫乏的二语者则对与自己口音类似的外国腔感知较好, 但二语经历较长的二语者在感知中却表现出较大灵活性。     

精神分裂症患者在听觉掩蔽环境下的言语识别

深入研究精神分裂症患者特异性的认知障碍有助于精神分裂症的早期发现、早期诊断和早期治疗.本综述在总结精神分裂症患者的听觉和言语识别异常以及听觉注意和听觉工作记忆缺陷的同时,重点阐述了精神分裂症患者完成言语听觉任务时的对掩蔽刺激特别信息掩蔽刺激的异常易感性.本文还特别指出,精神分裂症患者仍然具有利用言语内容启动线索来提高掩蔽下言语识别的能力.本文所总结的研究成果对探讨精神分裂症的病因学基础、寻找新的临床诊断以及治疗和康复手段都具有参考价值.     

语音型噪音对二语者汉语元音声调感知的影响

在安静、语音型噪音、语音调制型噪音三种背景下测量了汉语母语者、汉语中、高水平的韩语母语者感知汉语元音和声调的正确率。安静背景下,三组人的语音感知类似,而在语音型噪音背景下,汉语母语者的感知正确率显著高于中水平二语者。进一步的检验表明中水平二语者在语音型噪音背景下的感知难度较大是由于其受到的语音型噪音中能量掩蔽的影响比母语被试要大,而其受到的信息掩蔽的干扰和另外两组被试相近。     

Informational masking and auditory attention

Informational masking is broadly defined as a degradation of auditory detection or discrimination of a signal embedded ina context of other similar sounds; it is not related to energetic masking caused by physical interactions between signal and masker. In this paper, we report a systematic release from informational masking of a target tone in anine-tone rapid auditory sequence as the target is increasingly isolated in frequency or intensity from the remaieining sequence components. Improved target-tone frequency difference limens as isolation increases are interpreted as a reflection of increasingly focused auditory attention. The change from diffuse to highly focused attention is gradual over the frequency and intensity ranges examined, with each 1-dB increment in target intensity relative to the remaining components producing performance improvements equivalent to those produced by a 2% increase in frequency isolation. The results are modeled as bands of attention in the frequency and intensity domains. For attention directed by frequency isolation, there is a strong correspondence with auditory filters predicted by the power spectrum model of masking. These data also support the existence of an attention band of intensity, with a bandwidth of about 5–7 dB at the moderate levels used in this experiment.     

老龄化对F0轮廓线索在汉语言语识别去掩蔽作用的影响

动态基频(F0)轮廓有助于嘈杂环境下的言语识别,可以作为将目标语音从背景声中分离的知觉线索。本研究通过评估老年人与年轻人在言语掩蔽下聆听具有自然动态F0轮廓与对F0轮廓操作调节后的汉语语句的言语识别能力,探讨老龄化对F0轮廓线索在汉语言语识别去掩蔽作用中的影响。结果显示,在言语掩蔽下自然动态的F0轮廓比压扁或拉伸的F0轮廓更能帮助年轻人抵抗信息掩蔽识别目标言语;而老年人在言语掩蔽下却难以从动态F0轮廓线索中受益。研究结果揭示了老年人利用F0轮廓线索促进掩蔽下言语感知能力的老化特点。     

Informational masking and auditory attention.

Informational masking is broadly defined as a degradation of auditory detection or discrimination of a signal embedded in a context of other similar sounds; it is not related to energetic masking caused by physical interactions between signal and masker. In this paper, we report a systematic release from informational masking of a target tone in a nine-tone rapid auditory sequence as the target is increasingly isolated in frequency or intensity from the remaining sequence components. Improved target-tone frequency difference limens as isolation increases are interpreted as a reflection of increasingly focused auditory attention. The change from diffuse to highly focused attention is gradual over the frequency and intensity ranges examined, with each 1-dB increment in target intensity relative to the remaining components producing performance improvements equivalent to those produced by a 2% increase in frequency isolation. The results are modeled as bands of attention in the frequency and intensity domains. For attention directed by frequency isolation, there is a strong correspondence with auditory filters predicted by the power spectrum model of masking. These data also support the existence of an attention band of intensity, with a bandwidth of about 5-7 dB at the moderate levels used in this experiment.     

Effects of acoustic degradation on syntactic processing: implications for the nature of the resource system used in language processing

This study investigated the effect of noise masking on on-line syntactic processing. Ninety college students were tested on measures of working memory and on-line sentence comprehension. Subjects were divided equally into three listening conditions: no noise masking, -3 dB signal-to-noise ratio (S:N), -4.5 dB S:N. The auditory moving windows (AMW) paradigm was used to measure on-line sentence processing. In the AMW paradigm, subjects pressed a button for the successive presentation of each phrase in two types of sentences (syntactically simple and complex), and listening times were recorded for each phrase. Previous studies have shown that the verb in the more complex sentence type is the most capacity demanding portion of the sentence. Listening times were longer overall with increased noise masking, and listening times were longer overall at the verb of the harder sentence type. However, the increase at the verb was not larger with increased noise masking. All three groups showed similar effects of syntactic structure in the on-line data. The on-line syntactic effects were not due to problems in word recognition. Correlational analyses did not indicate a relationship between the increase in processing time at the capacity demanding region of the harder sentence types and any of the measures of working memory capacity in any of the three listening conditions. Results indicate that on-line sentence processing is not affected by noise masking if lexical access (e.g., word recognition) remains intact.     

The influence of speech rate and accent on access and use of semantic information

Circumstances in which the speech input is presented in sub-optimal conditions generally lead to processing costs affecting spoken word recognition. The current study indicates that some processing demands imposed by listening to difficult speech can be mitigated by feedback from semantic knowledge. A set of lexical decision experiments examined how foreign accented speech and word duration impact access to semantic knowledge in spoken word recognition. Results indicate that when listeners process accented speech, the reliance on semantic information increases. Speech rate was not observed to influence semantic access, except in the setting in which unusually slow accented speech was presented. These findings support interactive activation models of spoken word recognition in which attention is modulated based on speech demands.     

Perception of Native English Reduced Forms in Adverse Environments by Chinese Undergraduate Students

Previous research has shown that learners of English-as-a-second-language (ESL) have difficulties in understanding connected speech spoken by native English speakers. Extending from past research limited to quiet listening condition, this study examined the perception of English connected speech presented under five adverse conditions, namely multi-talker babble noise, speech-shaped noise, factory noise, whispering and sad emotional tones. We tested a total of 64 Chinese ESL undergraduate students, using a battery of listening tasks. Results confirmed that the recognition of English native speech was more challenging for Chinese ESL learners under unfavorable listening conditions, in comparison to a noise-free listening condition. These findings carry significant implications for the importance of training and assessments on connected speech perception across various listening environments.     

Breaking Surface Feature Continuity of Previewed Mask Reinstates Object Substitution Masking12

Perception of a briefly presented target is impaired when a sparse surrounding mask (e.g., four-dot) persists after target offset compared to when the target and mask offset together (i.e., object substitution masking [OSM]). Previous studies have reported a mask preview effect in which OSM is largely attenuated by prior presentation of the mask. Here, we investigated how breaking object continuity of the previewed mask affects the mask preview effect. Introducing an abrupt surface color change of the previewed mask at target onset disrupted the beneficial effect of mask preview, that is, OSM was reinstated (Experiment 1). The masking induced by mask color change exhibited the same two characteristics as conventional OSM: target location specificity and non-necessity of voluntary attention to the mask (Experiment 2). These results suggest that a sudden change in surface color breaks object continuity of the previewed mask and causes the mask to be represented as a new one, which triggers OSM anew.     

Perceptual order and the effect of vocalic context of fricative perception

This three-part study demonstrates that perceptual order can influence the integration of acoustic speech cues. In Experiment 1, the subjects labeled the [s] and [sh] in natural FV and VF syllables in which the frication was replaced with synthetic stimuli. Responses to these "hybrid" stimuli were influenced by cues in the vocalic segment as well as by the synthetic frication. However, the influence of the preceding vocalic cues was considerably weaker than was that of the following vocalic cues. Experiment 2 examined the acoustic bases for this asymmetry and consisted of analyses revealing that FV and VF syllables are similar in terms of the acoustic structures thought to underlie the vocalic context effects. Experiment 3 examined the perceptual bases for the asymmetry. A subset of the hybrid FV and VF stimuli were presented in reverse, such that the acoustic and perceptual bases for the asymmetry were pitted against each other in the listening task. The perceptual bases (i.e., the perceived order of the frication and vocalic cues) proved to be the determining factor. Current auditory processing models, such as backward recognition masking, preperceptual auditory storage, or models based on linguistic factors, do not adequately account for the observed asymmetries.     

Perceptual order and the effect of vocalic context on fricative perception

This three-part study demonstrates that perceptual order can influence the integration of acoustic speech cues. In Experiment 1, the subjects labeled the [s] and [∫] in natural FV and VF syllables in which the frication was replaced with synthetic stimuli. Responses to these “hybrid” stimuli were influenced by cues in the vocalic segment as well as by the synthetic frication. However, the influence of the preceding vocalic cues was considerably weaker than was that of the following vocalic cues. Experiment 2 examined the acoustic bases for this asymmetry and consisted of analyses revealing that FV and VF syllables are similar in terms of the acoustic structures thought to underlie the vocalic context effects. Experiment 3 examined the perceptual bases for the asymmetry. A subset of the hybrid FV and VF stimuli were presented inreverse, such that the acoustic and perceptual bases for the asymmetry were pitted against each other in the listening task. The perceptual bases (i.e., the perceived order of the frication and vocalic cues) proved to be the determining factor. Current auditory processing models, such as backward recognition masking, preperceptual auditory storage, or models based on linguistic factors, do not adequately account for the observed asymmetries.     

“To Name or Not to Name: That is the Question”: The Role of Response Inhibition in Reading

Reading is a complex process that includes the integration of information about letters (graphemes) and sounds (phonemes). In many circumstances, such as noisy environments, response inhibition is an additional factor that plays a marked role in successful oral reading. Response inhibition can take the form of task relevant inhibition (i.e., foils in a go/no-go task) and task irrelevant inhibition (i.e., distractor information). Here we investigated task relevant inhibition by having participants (N?=?30) take part in two tasks: go/no-go naming with nonwords foils (GNG-NW) and go/no-go naming with pseudohomophones foils (GNG-PH). Also, we investigated the addition of task irrelevant inhibition by having participants (N?=?28) take part in two tasks: GNG-NW?+?information masking and GNG-PH?+?information masking. We provide evidence that during a task relevant inhibition task, sub-word sound level information can be successfully inhibited, as evidenced by comparable response times for regular words and exception words, provided the foils do not contain familiar sound-based information (GNG-NW). In contrast, regular words were read aloud faster than exception words in a GNG-PH task, indicating that sub-word level interference occurs when the foils contain familiar sound-based information. The addition of task irrelevant inhibition (i.e., information masking at the phoneme level), served to increase response time overall, but did not impact the pattern of response times between regular words and exception words. Together these findings provide useful information regarding the role of response inhibition in word recognition and may be useful in computational models of word recognition and future work may benefit from accounting for the effects outlined in this paper.     

The effects of literacy on the recognition of dichotic words

The hypothesis that awareness of phonemic segments influences the way in which speech is perceived was examined. Illiterate adults, who generally lack awareness of segments, were compared with literates, who are aware of the segmental structure of speech, on the recognition of words presented dichotically. A group of people who learned to read and write but who do it only occasionally was also tested. The results indicated much better performance in literates than in illiterates or semiliterates. In addition, literates made proportionally more single-segment errors, especially those limited to the first consonant, and fewer global errors, i.e. on all the segments of a syllable, than illiterates. On the other hand, phonetic feature blendings were as frequent in illiterates as in literates. It is suggested that awareness of segments allows attention to be focused on the phonemic constituents of speech and thus contributes to better recognition in difficult listening conditions. However, awareness of segments does not influence the preattentive extraction of phonetic information.

The hypothesis that awareness of phonemic segments influences the way in which speech is perceived was examined. Illiterate adults, who generally lack awareness of segments, were compared with literates, who are aware of the segmental structure of speech, on the recognition of words presented dichotically. A group of people who learned to read and write but who do it only occasionally was also tested. The results indicated much better performance in literates than in illiterates or semiliterates. In addition, literates made proportionally more single-segment errors, especially those limited to the first consonant, and fewer global errors, i.e. on all the segments of a syllable, than illiterates. On the other hand, phonetic feature blendings were as frequent in illiterates as in literates. It is suggested that awareness of segments allows attention to be focused on the phonemic constituents of speech and thus contributes to better recognition in difficult listening conditions. However, awareness of segments does not influence the preattentive extraction of phonetic information.