基于谱减法的变频电子喉语音增强方法对比研究

目的电子喉(electrolarynx,EL)是喉头切除患者最常用的言语发声辅具,但是现有电子喉发声存在辐射噪声大的缺陷,通过消除辐射噪声以改善语音质量成为诸多研究者的目标。谱减类方法是目前消除基频恒定电子喉语音辐射噪声最常用的方法,但是对于变频电子喉语音而言,该类方法的有效性尚不得而知。因此,本文对比研究了不同谱减法对变频电子喉语音的去噪效果。方法首先分别介绍了经典谱减法、多带谱减法、基于感知加权技术的改进谱减法以及基于加权函数的改进谱减法的原理,然后在安静的环境下,让1名经过训练能够熟练使用电子喉的受试者(男)使用变频电子喉朗读给定的20句日常汉语普通话语句并录制作为电子喉语音原始数据,分别采用上述谱减方法对变频电子喉语音进行去噪处理,并对去噪后语音进行主、客观评价,比较不同谱减方法的去噪效果。结果客观结果表明,经典谱减法虽然去除了部分辐射噪声,但增强后语音仍然存在明显噪声。多带谱减法、基于感知加权技术的改进谱减法以及基于加权函数的改进谱减法均有效减少了辐射噪声,尤其是语音间隔段。然而,前两种方法增强后的语音在语音段仍存在少量噪声,而后一种方法增强后的语音在高频段有少量语音损失。主观结果表明,与原始电子喉语音相比,不同谱减法增强后的语音的可接受度有所提高,其中,基于加权函数的改进谱减法可接受度得分最高,而可懂度变化不大。结论对于选定的变频电子喉语音,基于谱减法的语音增强方法可以有效减少变频电子喉辐射噪声,提高语音的可接受度,改善语音的听觉质量,其中,基于加权函数的改进谱减法的去噪效果最好,但对于语音可懂度的影响不大。     

粤语与普通话大学生的普通话语音加工

目的:比较粤语大学生与普通话大学生普通话语音加工能力的异同,为第二语言学习和普通话教育的推广提供参考依据。方法:根据粤语、普通话双语历史评估,选择27名粤语大学生和30名普通话大学生为研究对象。采用oddball范式,对被试普通话的声母、韵母、声调意识进行测试;采用自编的快速命名测试(数字、字母、颜色、图形)对其进行命名速度测试;利用心理实验测试系统(PES)直接测试并记录被试的语音工作记忆得分。对上述结果采用独立样本t检验的方法进行比较。结果:粤语大学生韵母得分和总分低于普通话大学生(P<0.01),声母和声调得分两组差异无统计学意义。粤语大学生在数字、字母、颜色快速命名时间明显长于普通话大学生(均P<0.01),而图形快速命名时间两组差异无统计学意义;粤语大学生和普通话大学生工作记忆水平差异无统计学意义。结论:粤语大学生的普通话语音加工能力显著低于普通话大学生,主要体现在韵母意识和快速命名速度上。提示我们在今后的汉语语音加工研究中,应对粤语和普通话人群区别对待。     

基于ICA的重叠语音基频提取和语音增强

语音信号是一种特征时变信号,基音频率提取和语音增强是两种常见语音处理要求,独立分量分析（ICA）是一种盲信号处理方法,目的 在于将混合在观察信号中的相互独立的源信号分离出来,ICA在很多领域都有广泛的应用,在语音信号上最为成功,本文将ICA用来撮重叠语音信号中的基音频率,提出了一个基于ICA的混叠语音基频提取系统,成功地解决了基频相互接近时无法提取混合信号基频的问题,并将它应用到有音乐背景下的语音增强方面,均取得了较好的结果。     

联合使用助听器和增强电子耳蜗的使用者的中文语音识别

目的使用电子耳蜗与助听器联合的声学模拟考察在语音成形噪声中的中文语音识别.方法使用1增/1减的信噪比自适应变化过程,测试了6个具有正常听力、使用中文语言的被试者在语音成形噪声中的中文句子识别门限(speech recognitionthresholds,SRT).结果中文语音识别门限SRT随模拟系统中助听器的低通滤波截止频率变化的曲线呈现与低通滤波的幅频响应相似的形状.结论只要助听器恢复的残存低频声学听力覆盖了说话人的基频范围,这些低频信息就能显著地帮助电子耳蜗使用者在语音成形噪声中识别中文语音,无论电子耳蜗的整体输入频率范围与助听器恢复的频率范围是否交叠.     

电子耳蜗CIS方案与特征提取相组合的语音处理方法

本研究提出了一种改进的电子耳蜗语音信号处理策略，它将电子耳蜗连续交替取样波形策略(CIS策略)和特征提取策略相结合，既克服了CIS信号处理方案合成语音个性特征不明显的缺点，又消除了单独特征提取策略抗噪能力差的缺陷，使仿真后的电子耳蜗语音识别性能有了较好的改善。     

人工电子耳蜗语音信号处理方法的研究进展

人工电子耳蜗是全聋人健康的一项新技术。我们从系统角度出发，首先简单阐述了其原理及系统设计，在此基础上重点综述了目前人工电子耳蜗中所涉及的语音信号处理方法的研究进展状况，并对未来的研究提出了设想。     

基于OMAP-L137的电子耳蜗体外语音处理器的设计

电子耳蜗是目前唯一能使重度聋和全聋患者恢复听觉的医学装置,研制价格适中、基于汉语特征的电子耳蜗产品具有较高的经济效益和深远的社会意义.本文以新型DSP＋ARM双核低功耗处理器OMAP-L137为核心,设计并实现了一款电子耳蜗体外语音处理器原型,包括核心处理器单元、音频单元、SDRAM、NAND Flash、USB2.0 OTG接口、无线发射接口等模块.它实现了语音实时采集、连续交替采样算法处理,并根据刺激模式形成相应的刺激脉冲参数帧序列,发送到无线传输模块.通过对本系统和电子耳蜗无线传输模块、刺激电路进行联合调试,对语音采集、算法处理以及无线发射接口进行了验证,测试结果表明系统达到设计要求.     

频率信息对混叠语音环境下电子耳蜗患者汉语普通话识别效果的影响研究

多通道电子耳蜗产品在安静环境下取得了很好的言语识别效果,然而在混叠语音条件下,使用电子耳蜗患者的言语识别能力快速下降.通过在混叠语音条件下的听觉仿真试验,研究了不同算法对声音信息的传递效果,得出了频率信息对于混叠语音识别效果的重要影响,并借此提出要研究更有效的电子耳蜗语音处理算法.     

人体模型多通道电子语音解说系统的设计

介绍一种人体模型多通道电子语音解说系统的设计，该系统利用大规模 语音合成芯片的特点，建立了多路语音通道的手动寻址方式，实现了各路语音通过寻址电路和语音芯片的同步复位,完成了多路通道的录制与再生，因而提高了模型在医学教学中的价值。     

一种基于汉语音调信息的电子耳蜗语音信号处理新方案

本文在连续交替取样（Continuous Inteleaved Sampling,CIS)电子耳蜗语音处理方案的基础上,针对汉语语音信号的特点,提出一种基于汉语音调信息的语音信号处理新方案。文中首先讨论了汉语语音的特点,并初步讨论了音调的变化对语音信号处理效果的影响。结果表明,将汉语的音调变化信息加入到CIS语音信号处理方案中,可明显地提高汉语的识别能力,基于本文的结果,可以设计出适合中国聋人的电子耳蜗。     

Enhancement of electrolarynx speech using adaptive noise cancelling based on independent component analysis

The electrolarynx provides a valuable means of verbal communication for people who cannot use their natural voice-production mechanism, but technology has changed very little since it was introduced in the 1950s. The presence of background noise degrades the resulting speech. In this study background noise was reduced by a new method, independent component analysis-based adaptive noise cancelling, which can remove noise components of the primary input signal based on statistical independence, by incorporating both second-order and higher-order statistics. The method shows better performance than the conventional least mean square algorithm. Acoustic analysis of the denoised electrolarynx speech revealed a significant reduction in the amount of background noise. Results from the perceptual evaluations indicated that the new filtering technique produced a noticeable improvement in the acceptability of the electrolarynx speech in a quiet environment (from 1.75 to 2.49, arbitrary units) or a noisy environment (from 0.59 to 1.82). In general, there was no significant improvement or degradation in intelligibility in the quiet environment (from 52.7 to 53.3). However, the processing did improve the intelligibility in a babble-noise environment (from 24.9 to 40.6). The improvement in acceptability and intelligibility may increase the communication ability of the user in daily situations.     

基于统计学的生理期语音特征分析

目的：建立快速准确且安全无创的生理期语音监测模式。方法：采用中医闻声诊技术对育龄期女性进行生理期语音特征分析,分别以排卵期、月经期、痛经程度作为判别依据,筛选出可反映上述指征的差异性语音频率特征,拟建立相关回归模型。结果：在242项语音指标中分析得出排卵期与非排卵期、月经期与非月经期、4种痛经程度中,分别有14、11、4项语音特征指标差异具有统计学意义,其中与排卵期相关的语音特征指标为语音第五共振峰高度和最持续帧最大能量频率占时比,与月经期呈负相关的语音特征指标为最高能频段序号,与痛经程度呈正相关的语音特征指标为音阶。结论：育龄期女性在生理期语音呈现特征性变化,对排卵期、月经期具有一定的预测能力,对痛经程度的量化具有一定的参考价值。     

Emotional self–other voice processing in schizophrenia and its relationship with hallucinations: ERP evidence

Abnormalities in self–other voice processing have been observed in schizophrenia, and may underlie the experience of hallucinations. More recent studies demonstrated that these impairments are enhanced for speech stimuli with negative content. Nonetheless, few studies probed the temporal dynamics of self versus nonself speech processing in schizophrenia and, particularly, the impact of semantic valence on self–other voice discrimination. In the current study, we examined these questions, and additionally probed whether impairments in these processes are associated with the experience of hallucinations. Fifteen schizophrenia patients and 16 healthy controls listened to 420 prerecorded adjectives differing in voice identity (self‐generated [SGS] versus nonself speech [NSS]) and semantic valence (neutral, positive, and negative), while EEG data were recorded. The N1, P2, and late positive potential (LPP) ERP components were analyzed. ERP results revealed group differences in the interaction between voice identity and valence in the P2 and LPP components. Specifically, LPP amplitude was reduced in patients compared with healthy subjects for SGS and NSS with negative content. Further, auditory hallucinations severity was significantly predicted by LPP amplitude: the higher the SAPS “voices conversing” score, the larger the difference in LPP amplitude between negative and positive NSS. The absence of group differences in the N1 suggests that self–other voice processing abnormalities in schizophrenia are not primarily driven by disrupted sensory processing of voice acoustic information. The association between LPP amplitude and hallucination severity suggests that auditory hallucinations are associated with enhanced sustained attention to negative cues conveyed by a nonself voice.     

全喉切除术后食管语康复实践

目的总结喉全切除术食管发声训练和效果。方法对我院自1998年6月～2003年6月的59例喉癌、下咽癌全喉切除术后患者,进行食管发声康复训练。结果53例(89.8%)获得不同程度的发声功能,46例无喉者的言语水平接近正常喉言语水平,他们的最大发音时程较长、听距较远,言语可懂度高,较流利;7例发音效果差,但言语可懂度仍高;不能发声者仅6例。结论与其它发声重建相比,食管发声能很快学会发基本音,并具有发声成功率高、发声质量良好等优点。     

A causal test of the motor theory of speech perception: a case of impaired speech production and spared speech perception

The debate about the causal role of the motor system in speech perception has been reignited by demonstrations that motor processes are engaged during the processing of speech sounds. Here, we evaluate which aspects of auditory speech processing are affected, and which are not, in a stroke patient with dysfunction of the speech motor system. We found that the patient showed a normal phonemic categorical boundary when discriminating two non-words that differ by a minimal pair (e.g., ADA–AGA). However, using the same stimuli, the patient was unable to identify or label the non-word stimuli (using a button-press response). A control task showed that he could identify speech sounds by speaker gender, ruling out a general labelling impairment. These data suggest that while the motor system is not causally involved in perception of the speech signal, it may be used when other cues (e.g., meaning, context) are not available.     

Slow tonic muscle fibers in the thyroarytenoid muscles of human vocal folds; a possible specialization for speech

Most of the sounds of human speech are produced by vibration of the vocal folds, yet the biomechanics and control of these vibrations are poorly understood. In this study the muscle within the vocal fold, the thyroarytenoid muscle (TA), was examined for the presence and distribution of slow tonic muscle fibers (STF), a rare muscle fiber type with unique contraction properties. Nine human TAs were frozen and serially sectioned in the frontal plane. The presence and distribution pattern of STF in each TA were examined by immunofluorescence microscopy using the monoclonal antibodies (mAb) ALD‐19 and ALD‐58 which react with the slow tonic myosin heavy chain (MyHC) isoform. In addition, TA muscle samples from adjacent frozen sections were also examined for slow tonic MyHC isoform by electrophoretic immunoblotting. STF were detected in all nine TAs and the presence of slow tonic MyHC isoform was confirmed in the immunoblots. The STF were distributed predominantly in the medial aspect of the TA, a distinct muscle compartment called the vocalis which is the vibrating part of the vocal fold. STF do not contract with a twitch like most muscle fibers, instead, their contractions are prolonged, stable, precisely controlled, and fatigue resistant. The human voice is characterized by a stable sound with a wide frequency spectrum that can be precisely modulated and the STF may contribute to this ability. At present, the evidence suggests that STF are not presented in the vocal folds of other mammals (including other primates), therefore STF may be a unique human specialization for speech. Anat Rec 256:146–157, 1999. © 1999 Wiley‐Liss, Inc.     

The Effects of Changes in Motivation on Alpha Enhancement

The effect of varying monetary reinforcement on performance in an occipital alpha enhancement situation was examined. It was found that alpha output was increased with larger rewards but that the changes in performance were not linearly related to size of reward.     

Effects of seeing and hearing speech on speech production: a response time study

Research demonstrates that listening to and viewing speech excites tongue and lip motor areas involved in speech production. This perceptual-motor relationship was investigated behaviourally by presenting video clips of a speaker producing vowel-consonant-vowel syllables in three conditions: visual-only, audio-only, and audiovisual. Participants identified target letters that were flashed over the mouth during the video, either manually or verbally as quickly as possible. Verbal responses were fastest when the target matched the speech stimuli in all modality conditions, yet optimal facilitation was observed when participants were presented with visual-only stimuli. Critically, no such facilitation occurred when participants were asked to identify the target manually. Our findings support previous research suggesting a close relationship between speech perception and production by demonstrating that viewing speech can ‘prime’ our motor system for subsequent speech production.

基于一种新型模糊增强算法的眼底图像增强

眼底图像是细节较多的复杂图像,Ｐａｌ等人的提出的模糊增强算法对增强这类图像有着较好的效果。但这种算法存在着处理速度较性和容易损失信息的缺陷。针对这一情况,本文提出了一种改进后的模糊增强算法。实验证明,改进后的模糊增强算法对眼底图像的增强有着更好的效果。