语音编码技术及其硬件实现

压缩编码技术是无线语音通信的关键技术之一。介绍了语音编码技术的基本概念及分类,并选用AMBE多带激励压缩编码算法,通过单片机控制专用语音压缩DSP芯片,提出了一种适合低速无线语音、数据实时通信的系统解决方案,完成了硬件、软件设计,实现了低速率下的语音、数据的同步大气传输。测试结果显示,在语音编码速率为2．4kbps以下时,仍然可以得到音质较好的语音输出。     

Psychogenic Voice Disorders in Performers: A Psychodynamic Model

Psychogenic voice disorders are not infrequently encountered in the busy voice clinic. A clinician-friendly psychodynamic model and a multidisciplinary management approach are presented which have proven helpful for our voice team and our patients. In essence the formulation revolves around an “event” occurring, which may be either organic or psychological in nature. The ensuing dysphonia then leads to emotional consequences which in turn have physical consequences on the vocal tract. The situation can become reinforcing and illness behaviors develop. Elucidating this event/process to the patient improves the likelihood of a successful long-term outcome. The diagnostic and management roles of the various team members are discussed.     

Relationship between subjective voice complaints and acoustic parameters in female teachers'' voices

The aim of the study was to identify the acoustic correlates of female teachers' subjective voice complaints by recording their voices in their working environment. The subjects made recordings during lessons (N = 10) and breaks (N = 11). The subjects were divided into 2 groups: those with few voice complaints (FC group) and those with many voice complaints (MC group). The speech sample made in the breaks was maximally sustained /a/, from which fundamental frequency (F0), jitter, and shimmer were analyzed. The classroom samples were analyzed for F0, sound pressure level (SPL), and F0 time (the active vibration time of the vocal folds). Additionally, an index for assessing voice loading is presented. The results revealed a tendency of the MC group to have higher F0 and lower SPL and perturbation values than the FC group. The index values correlated moderately with the subjective vocal complaints.     

Study of the elderly females'' voice by phonetography

This study was carried out to investigate the voice characteristics of 40 healthy females with no voice disorders, ranging in age from 60 to 84 years (X = 68.2+/-5.74 years). Measurements over all the entire phonational range were obtained by phonetography. The subjects were asked to sustain the vowel /a/ in modal register for a minimum of 5 seconds in the highest and lowest intensities after hearing the semitones C, E, G, and A, over all phonational ranges. The results indicated expansion of the low and reduction of high ends of the pitch range, decrease of the pitch numbers of the vocal range, restriction of the lowest and highest limits of the intensity, and reduction of either the maximum phonational range and the phonetogram area. The phonetography technique has shown efficacy to investigate the voice characteristics of elderly females.     

Acoustic concomitants of emotional expression in operatic singing: The case of lucia in Ardi gli incensi

Two excerpts from the cadenza in Ardi gli incensi from Donizetti's opera Lucia di Lammermoor were acoustically analyzed for five recorded versions of the cadenza by Toti dal Monte, Maria Callas, Renata Scotto, Joan Sutherland, and Edita Gruberova. These acoustic parameters of the singing voices were correlated with preference and emotional expression judgments, based on pairwise comparisons, made by a group of experienced listener-judges. In addition to showing major differences in the voice quality of the five “dive” studied, the acoustic parameters suggested which vocal cues affect listener judgments. Two component scores, based on a factorial-dimensional analysis of the acoustic parameters, predicted 84% of the variance in the preference ratings.