Combination of pitch synchronous analysis and fisher criterion for speaker identification

A novel text independent speaker identification system is proposed. In the proposed system, the 12-order perceptual linear predictive cepstrum and their delta coefficients in the span of five frames are extracted from the segmented speech based on the method of pitch synchronous analysis. The Fisher ratios of the original coefficients then be calculated, and the coefficients whose Fisher ratios are bigger are selected to form the 13-dimensional feature vectors of speaker. The Gaussian mixture model is used to model the speakers. The experimental results show that the identification accuracy of the proposed system is obviously better than that of the systems based on other conventional coefficients like the linear predictive cepstral coefficients and the Mel-frequency cepstral coefficients.     

基于SHS的重叠语音基音分离检测方法

运用SHS(分谐波累加)法可准确地提取单个语音的基音周期,本文将该方法推广运用到重叠语音基音的分离检测,并提出了相应的检测方法.实验证明,本文提出的方法能有效地分离并提取两重叠语音的基音,即使对于基音周期相差较近的两个重叠语音也能取得较好的结果.     

基于预搜索策略的ACELP语音编码算法

基于预搜索策略的ACELP语音编码算法     

基于小波变换的汉语声调识别新方法

利用小波变换能够模拟人耳听觉特性的优点及其时频局部化特性,对实际语音信号进行分析。根据小波变换模极大值原理以及语音信号的奇异和瞬态特性,提出了一种新的小波变换峰值检测算法。该算法可用于精确提取语音的基音周期,准确进行声调识别。最后,给出应用实例说明了本文算法的有效性。     

板变形研究与改善

PCB设计逐步向薄、精、密方向发展,要求PCB所使用的芯板越来越薄、图形设计间距越来越小;降低成本提高拼版利用率的大趋势势必要求拼版尺寸越来越大,这些都对PCB的尺寸稳定性提出了更高的要求,本项目将针对PCB压合后变形进行研究、对其影响因素进行分析改善,最终得出控制PCB变形的方法。     

Pitch Matching Accuracy of Trained Singers, Untrained Subjects with Talented Singing Voices, and Untrained Subjects with Nontalented Singing Voices in Conditions of Varying Feedback

At a physiological level, the act of singing involves control and coordination of several systems involved in the production of sound, including respiration, phonation, resonance, and afferent systems used to monitor production. The ability to produce a melodious singing voice (eg, in tune with accurate pitch) is dependent on control over these motor and sensory systems. To test this position, trained singers and untrained subjects with and without expressed singing talent were asked to match pitches of target pure tones. The ability to match pitch reflected the ability to accurately integrate sensory perception with motor planning and execution. Pitch-matching accuracy was measured at the onset of phonation (prephonatory set) before external feedback could be utilized to adjust the voiced source, during phonation when external auditory feedback could be utilized, and during phonation when external auditory feedback was masked. Results revealed trained singers and untrained subjects with singing talent were no different in their pitch-matching abilities when measured before or after external feedback could be utilized. The untrained subjects with singing talent were also significantly more accurate than the trained singers when external auditory feedback was masked. Both groups were significantly more accurate than the untrained subjects without singing talent.     

Potential factors related to untrained singing talent: a survey of singing pedagogues

A national survey was conducted to identify factors associated with untrained singing talent based on perceptions obtained from a homogeneous group of professional singing pedagogues. Survey items included questions related to the perception of singing talent, factors associated with untrained singing talent, and physiological variables that distinguished untrained singing talented individuals from those without obvious singing talent. The survey data suggested that intonation, timbre, and musicality were rated the most important factors associated with the perception of singing talent in an untrained individual. Environmental influences and genetics were rated most important for explaining why one individual would express singing talent and another would not. In addition, the data suggested that abilities related to the control of pitch distinguished untrained talented individuals from those without singing talent more than other physiological variables.     

Perceived Pitch of Synthesized Voice with Alternate Cycles

Both in normal speech voice and in some types of pathological voice, adjacent vocal cycles may alternate in amplitude or period, or both. When this occurs, the determination of voice fundamental frequency (defined as number of vocal cycles per second) becomes difficult. The present study attempts to address this issue by investigating how human listeners perceive the pitch of alternate cycles. As stimuli, vowels /a/ and /i/ were synthesized with fundamental frequencies at 140 Hz and 220 Hz, and the effect of alternate cycles was simulated with both amplitude- and frequency-modulation of the glottal volume velocity waveform. Subjects were asked to judge the pitch of the modulated vowels in reference to vowels without modulation. The results showed that (a) perceived pitch became lower as the amount of modulation increased, and the effect seems to be more dramatic than would be predicted by existing hypotheses, (b) perceived pitch differed across vowels, fundamental frequencies, and modulation types, that is, amplitude versus frequency modulation, and (c) the prediction of perceived pitch was best made in the frequency domain in terms of subharmonic-to-harmonic ratio. These findings provide useful information on how we should assess the pitch of alternate cycles. They may also be helpful in developing more robust pitch determination algorithms.     

TWO KINDS OF PITCH PREDICTORS IN SPEECH COMPRESSING CODING

This paper studies two kinds of methods for pitch predictor in speech compressing coding, i.e., open-loop and closed-loop structures. Some of simplified approaches for solving pitch predictor equation are suggested, and the performances are compared under several conditions. The computer simulation results are shown.