Voice Classes Research Articles

Analysis of GSM/GPRS Cell with Multiple Data Service Classes

This paper is concerned with the performance modelling and evaluation of a General Packet Radio Service (GPRS) for a wireless Global System for Mobile telecommunication (GSM) cell involving both voice and multiple class data services under a complete partitioning scheme (CPS). The GPRS is modelled as a system of access and transfer queues in tandem having an external multiple class compound Poisson bursty traffic with geometrically distributed batches under first-come-first-served (FCFS) and generalised processor-sharing (PS) scheduling disciplines, respectively. The proposed queueing model is valid for both uplink and downlink connections and provides multiple class data services with different arrival rates, interarrival-time squared coefficients of variation (SCVs), file (burst) sizes and different PS discrimination service levels. Based on the principle of maximum entropy (ME), a product form approximation is characterised for the two queues in tandem, subject to queueing theoretic mean value constraints. The ME solution implies a decomposition of the system into individual single server building block queues, each of which can be analysed in isolation. Consequently, ME closed form expressions and simulation results for the aggregate state probability together with the marginal mean queue length and blocking probability are divised to assess the credibility of the ME solution and also to study the effect of external GPRS bursty traffic upon the performance of the wireless cell.

Resource allocation for multiple classes of DS-CDMA traffic

We consider a packet data direct-sequence code-division multiple-access (DS-CDMA) system which supports integrated services. The services are partitioned into different traffic classes according to information rate (bandwidth) and quality of service (QoS) requirements. Given sufficient bandwidth, QoS requirements can be satisfied by an appropriate assignment of transmitted power and processing gain to users in each class. The effect of this assignment is analyzed for both a single class of data users and two classes of voice and data users. For a single class of data users, we examine the relationship between average delay and processing gain, assuming that ARQ with forward error correction is used to guarantee reliability. The only channel impairment considered is interference, which is modeled as Gaussian noise. A fixed user population is assumed and two models for generation of data packets are considered: (1) each user generates a new packet as soon as the preceding packet is successfully delivered and (2) each user generates packets according to a Poisson process. In each case, the packets enter a buffer which is emptied at the symbol rate. For the second traffic model, lowering the processing gain below a threshold can produce multiple operating points, one of which corresponds to infinite delay. The choice of processing gain which minimizes average delay in that case is the smallest processing gain at which multiple operating points are avoided. Two classes of users (voice/data and two data classes) are then considered. Numerical examples are presented which illustrate, the increase in the two-dimensional (2-D) capacity region achievable by optimizing the assignment of powers and processing gains to each class.

Voicing-specific LPC quantization for variable-rate speech coding

Phonetic classification of speech frames allows distinctive quantization and bit allocation schemes suited to the particular class. Separate quantization of the linear predictive coding (LPC) parameters for voiced and unvoiced speech frames is shown to offer useful gains for representing the synthesis filter commonly used in code-excited linear prediction (CELP) and other coders. Subjective test results are reported that determine the required bit rate and accuracy in the two classes of voiced and unvoiced LPC spectra for CELP coding with phonetic classification. It was found, in this context, that unvoiced spectra need 9 b/frame or more whereas voiced spectra need 25 b/frame or more with the quantization schemes used. New spectral distortion criteria needed to assure transparent LPC spectral quantization for each voicing class in CELP coders are presented. Similar subjective test results for speech synthesized from the true residual signal are also presented, leading to some interesting observations on the role of the analysis-by-synthesis structure of CELP. Objective performance assessments based on the spectral distortion measure are also presented. The theoretical distortion-rate function for the spectral distortion measure is estimated for voiced and unvoiced LPC parameters and compared with experimental results obtained with unstructured vector quantization (VQ). These results show a saving of at least 2 b/frame for unvoiced spectra compared to voiced spectra to achieve the same spectral distortion performance.

Vocal fold strain and vocal pitch in singing:Radiographic observations of singers and nonsingers

The relationship between vocal fold strain and vocal pitch in singers and nonsingers singing a rising pitch series has been indirectly investigated by means of lateral radiographs. Nonsingers tend to exhibit more strain than singers. To standardize the degree of strain, an index of strain per semitone is proposed. The semitone strain indicates the average amount of strain per 1 semitone of pitch increase or decrease. The index has been shown to be affected by several factors: gender, singing training, singing technique, voice class, age, and status of muscle function. Observations suggest that similar groups of individuals occupy different positions on the stress-strain curve, indicated by their semitone strain values.

Distributed Bandwidth Management in FDDI Networks with Multiple Isochronous Services

The Fiber Distributed Data Interface (FDDI) is a proposed American National Standard for a 100 Mbps token ring using an optical fiber medium. The timed token protocol used in FDDI allows the integration of digital voice, video, interactive data communications and large file transfers over the same network. The performance of the protocol has been studied in the past for asynchronous class of service with a single isochronous service.In this paper, we focus on the performance of the protocol when multiple class of isochronous services are to be provided along with the asynchronous class of service. It is found that the performance of the protocol is affected by the different delay requirements of different isochronous services. The performance of the protocol is studied through simulation with two classes of isochronous services viz video and voice. We also propose two distributed algorithms to improve the performance of the protocol under multiple isochronous services.

Discussion of vocology panel presented at the nineteenth annual symposium: Care of the professional voice

Ronald Scherer: There are many of you in the audience who would be extremely effective on this panel today. I hope that in the interactive portion of this session you will get up and say what's on your mind and help in this discussion of curricula. I would like to welcome Harry Hollien, Krzysztof Izdebski, Lucille Rubin, and Robert Sataloff on this panel with Ingo Titze. Each of them will give a 3-5 minute presentation of their own views on this matter. We will then have Ingo give a response if he would like to. After that, we will open it up for discussion among the audience members and the panel and see where we go. So please enjoy this portion of the program. Lucille, would you like to begin? Lucille Rubin: I would like to congratulate Ingo Titze on a fine article. Standards of training have long been a concern to Ingo, and I am pleased he has addressed these concerns in the proposed vocology curriculum. His article reconfirms that speech pathologists and voice trainers may have different tasks but share common goals in rehabilitation and training. My remarks are limited to the part of Ingo's article on education. I have four responses to the proposed curriculum and two personal opinions on training. First, the proposed curriculum appears deficient in two areas: processing and teaching. One needs to physically process information before one can teach process to others. Taking a private voice class once a week or demonstrating one's skills on one singing student does not allow sufficient processing or teaching time. A year spent applying new vocal skills to one's own voice and another half year in teaching others should be added. Second, although important objectives are clearly

Experiments of automatic speaker recognition in open sets

In automatic speaker recognition tasks a situation may occur in which it cannot be assumed that a voice to be recognized belongs to a known set of voice classes (a closed set). Thus, a problem arises with respect to working out a recognition algorithm that could operate in open sets of speakers, i.e. without assuming that a speech sample from an unknown speaker must belong to one of the speakers of a given set. This paper presents together with some relevant experiments a method for automatic speaker recognition in open sets. This method ensures the effective rejection of outsiders. Two “key words” were examined, as were different parameter sets and large and small populations of speakers. The methodological assumptions and experimental results show that the proposed open set voice recognition method is very flexible and makes it possible to adjust global characteristics, i.e. α and β errors, to the strategy adopted by the recognition system. For a given set of voice patterns, it is always possible to optimize recognition by a proper selection of approximations of the ground class distribution, i.e. by an appropriate selection of decision thresholds.

Acoustical study of certain parameters of voice quality and their influence on voice classification in male singers

An investigation to determine the significance of formant frequencies, pitch, and source spectrum slope on voice classification is reported. Eight professional singers sang five common vowels on four common pitches, and, in a forced-choice test, vocal pedagogues classified the vocalizations as tenor, baritone, or bass. Source spectrum slopes of −12 dB per octave approximated the vocalizations of the three voice classes, while formant frequencies and pitch accounted for most of the difference in jury evaluation results. To evaluate more accurately the significance of formant frequencies, pitch, and source slope on voice classification, vowel synthesis was employed. The independent variables, representative voice class formant frequency combinations, four different pitches, and source spectrum slope were systematically altered as dependent variables, vibrato, and vowels were stabilized. The original jury classified the synthesis in a forced-choice test, and the dependence of the jury evaluation upon formant frequencies and pitch was evidenced in percentage and analysis of variance tests. Formant frequency percentage differences between basses and tensors were similar to those found between males and females. The results suggest that voice classification in male singers is dependent on at least one significant property: the formant frequencies of the singer.

Voice Classes Won't Work in My School! (Really?)

* To a music teacher whose only conscious remembrance of college voice study is out-of-tune and outof-breath renditions of Bayly's Long, Long Ago or Edward Purcell's Passing By, serious consideration of instituting voice classes at the high school level is bound to seem a mistake. To those, however, who have been exposed to voice study with competent teachers, the idea of presenting such study at the secondary level may not appear to be too undesirable or unrealistic.

Voice Classes in Senior High Schools

Voice Classes in Senior High Schools

Historical Data—High School Voice Classes

Historical Data—High School Voice Classes