Telephone Transmission Research Articles

Automatic Speaker Recognition System Based on Gaussian Mixture Models, Cepstral Analysis, and Genetic Selection of Distinctive Features

This article presents the Automatic Speaker Recognition System (ASR System), which successfully resolves problems such as identification within an open set of speakers and the verification of speakers in difficult recording conditions similar to telephone transmission conditions. The article provides complete information on the architecture of the various internal processing modules of the ASR System. The speaker recognition system proposed in the article, has been compared very closely to other competing systems, achieving improved speaker identification and verification results, on known certified voice dataset. The ASR System owes this to the dual use of genetic algorithms both in the feature selection process and in the optimization of the system's internal parameters. This was also influenced by the proprietary feature generation and corresponding classification process using Gaussian mixture models. This allowed the development of a system that makes an important contribution to the current state of the art in speaker recognition systems for telephone transmission applications with known speech coding standards.

СУЧАСНІ ЗАСОБИ ЗВ’ЯЗКУ ТА ІНФОКОМУНІКАЦІЙНІ ТЕХНОЛОГІЇ У ЗБРОЙНИХ СИЛАХ УКРАЇНИ ТА НАЦІОНАЛЬНІЙ ГВАРДІЇ УКРАЇНИ: СЬОГОДЕННЯ ТА ПЕРСПЕКТИВИ ЗАСТОСУВАННЯ

A brief analysis of modern means of communication and information communication technologies in the Armed Forces and the National Guard of Ukraine was conducted. Determination of the main directions of development and prospects for the use of information and communication technologies in the Armed Forces and the National Guard of Ukraine. The construction of a communication system that integrates the functions of troop management, weapons, intelligence, radio-electronic warfare, as well as communication, navigation, orientation, should be created in accordance with the concept of troop management adopted in NATO countries on the basis of the construction of a single information space. Brief conclusions are given regarding the assessment of the possibility of organizing the interaction of the Armed Forces and the National Guard of Ukraine. Modern complex communication hardware of the Armed Forces and field telecommunication nodes and complex telecommunication hardware at NSU were considered. It was determined that according to their purpose and composition, they have the same characteristics and are intended to ensure communication, automatic switching and routing of digital flows between communication nodes of control points of different ranks, for the organization (deployment) of subscriber networks of telephone communication and data transmission , provision of telecommunication control points of all management units of the Armed Forces and NGU, other law enforcement agencies of special purpose in all types of combat for the services of operational staff on channels created by various means of communication. A promising concept of a single information space combining modern digital means of communication of Harris for the Armed Forces of Ukraine and Aselsan for the Armed Forces of Ukraine at the same time in the framework of Mesh and MANET technology is proposed for consideration.

Implementation of a 46-node quantum metropolitan area network

Quantum key distribution (QKD) enables secure key exchanges between two remote users. The ultimate goal of secure communication is to establish a global quantum network. The existing field tests suggest that quantum networks are feasible. To achieve a practical quantum network, we need to overcome several challenges including realizing versatile topologies for large scales, simple network maintenance, extendable configuration and robustness to node failures. To this end, we present a field operation of a quantum metropolitan-area network with 46 nodes and show that all these challenges can be overcome with cutting-edge quantum technologies. In particular, we realize different topological structures and continuously run the network for 31 months, by employing standard equipment for network maintenance with an extendable configuration. We realize QKD pairing and key management with a sophisticated key control centre. In this implementation, the final keys have been used for secure communication such as real-time voice telephone, text messaging and file transmission with one-time pad encryption, which can support 11 pairs of users to make audio calls simultaneously. Combined with intercity quantum backbone and ground–satellite links, our metropolitan implementation paves the way toward a global quantum network.

Telemedicine in the management of hypertension: Evolving technological platforms for blood pressure telemonitoring.

The prevalence of hypertension is high and still increasing in almost all communities regardless of high, middle, or low income. The control rate remains low in most countries. Telemedicine offers possibilities to improve blood pressure control. The past two decades witnessed the fast evolving telecommunication from telephone transmission to smart mobile phone technology for telemedicine. There is some evidence from randomized controlled trials that telemonitoring improves blood pressure control. However, it requires co‐interventions. The emerging new technology may offer even more possibilities in telemonitoring and co‐interventions, for instance, an interactive platform between patients and health professionals for the management of hypertension. Telemedicine might ultimately change the situation of the unsatisfactory management of hypertension in many communities. It helps fully utilize antihypertensive treatment, the most effective cardiovascular prevention, to achieve the goal of ending atherosclerosis and arteriosclerosis in humans.

Update on cardiac implantable electronic devices: from the injectable loop recorder to the leadless pacemaker, to the subcutaneous defibrillator.

A very fast-paced improvement of technology in the field of cardiac implantable devices has been observed in the last ten years. The aim of this review is to highlight the most important innovations which have been recently introduced in this field, such as the leadless pacemaker (a heart stimulator without intracardiac leads), the subcutaneous defibrillator (a completely extracardiac defibrillator device), the injectable loop recorder (a miniaturized subcutaneous continuous echocardiographic monitor provided by alarms and telephonic transmission) and many other new devices which will completely change the clinical practice in this field over the next decade.

The Effect of Telephone Transmission on Voice Quality Perception

This study aims to analyze the effect of telephone transmission on the voice quality perception of subjects with dysphonia and seeks to contribute to the use of perceptual voice analysis in forensic context. The main hypothesis is that the auditory perception of voice quality differs according to the acoustic quality of the speech material. Eight male speakers were simultaneously recorded directly by a digital recorder and over a mobile phone. A perceptual experiment containing 21 speech samples was used. The samples were analyzed via an online adaptation of the Vocal Profile Analysis Scheme (VPAS) into Brazilian Portuguese by a group of six voice-specialized professionals. Data analysis included the relative frequency of the 10 most evaluated VPAS settings in both recording conditions, and the relative frequency of the VPAS groups of features. A multidimensional scaling technique was applied to investigate the perceptual distance between stimuli pairs from both recording conditions. This was followed by a nonparametric multiple linear regression analysis that aimed to comprehend the underlying variables that motivated the spatial arrangement of the stimuli. The telephone transmission effect may have an influence on assessing correctly the supralaryngeal, laryngeal, prosodic, and temporal VPAS settings. The perceptual distance between stimuli pairs were mainly motivated by the rating of velopharyngeal system, respiratory support, laryngeal tension, speech rate, and creaky voice. The auditory perception differences between the stimuli pairs with different acoustic qualities could be related to the mobile phone bandwidth and data compression, and to telephone interaction characteristics. A group of laryngeal, supralaryngeal, temporal, and respiratory settings was mainly related to the dissimilarities reported. In terms of the application of VPAS in forensic context, the protocol was considered a relevant scientific tool that enables standardizing and analysis comparison among different groups of forensic specialists.

Comparison of spectral tilt measures for sentence prominence in speech—Effects of dimensionality and adverse noise conditions

Linguistic prominence in speech is known to correlate with the acoustic measures of energy, F0, and duration. In contrast, the role of spectral tilt in the realization of prominence has remained more inconsistent between previous empirical investigations. This may be partially due to the lack of a standard method for quantifying spectral tilt or due to difficulties in estimating the acoustical source of spectral tilt, the glottal flow, from continuous speech. These issues have rendered interpretations and comparisons between studies difficult. In addition, (i) little is known about the robustness of tilt estimators for prominence detection in the case when speech is not clean but corrupted, as in real life, by environmental noise or telephone transmission (i.e. degradation caused by bandpass filtering and quantization noise). Moreover, (ii) little attention has been paid to multidimensional representations of source spectrum that can potentially incorporate more information about the phonation style than purely scalar measures. In this work, we study spectral tilt in signaling prominence in spoken Dutch and French under different levels of additive noise, and for telephone-band coded speech, and compare several one-dimensional tilt measures that have been previously encountered in the literature as well as multidimensional tilt measures. We also compare spectral tilt measures with other standard acoustic correlates for prominence, namely, energy, F0, and duration. Our results provide further empirical support for the finding that tilt is a systematic correlate of prominence in Dutch, that the role is smaller in French, and that energy, F0, and duration appear still to be the most robust features for discriminating prominent and non-prominent words. In addition, our results show that there are notable differences between different tilt measures at different levels of noise, and that multidimensional representations for tilt improve class separability from the scalar measures.

Automated Fault Recognition in Power Line Patrolling Using GSM and IoT Technology

Today's civil constructions are developed using closed wiring so detecting of fault is becoming a big task to identify and solve where the fault is being located. So a pulse-type echo ranging fault locator has been developed which is suitable for locating sustained faults on telephone and power transmission lines. A number of these instruments have been in service for several years. They have been used to locate a wide variety of power and telephone line faults with signifcant reductions in service interruptions and economies in line patrolling. Before a new circuit is energized it may be tested with the line scope to ensure that all construction grounds have been removed and that all transpositions are correct. Telephone circuits also may be tested to locate sources of mismatch which introduce transmission losses. An automated fault recognizer has been developed, which operates on the same principle and which without any human intervention records the locations of sustained or transient power line faults.

Effect of pole size on preservative penetration and retention in air-dried ugandan grown eucalypt utility poles

Treated wooden utility poles, from trees such as eucalypts, are the most commonly used for telephone and electricity transmission lines in Uganda. In the last decade, however, frequent failure of wooden poles in service has been reported, likely due to the preservative chemical, wood used or the treatment process. The objective of this study was to assess the creosote preservative penetration and retention in eucalypt wood. A total of 126 Eucalyptus grandis poles i.e. 42 poles for each size category, with an average moisture content of below fibre saturation point (28%) were treated in different charges depending on their size. In length, poles used were 9, 11 and 14m. Every charge consisted of poles within the same size category. The Full Cell pressure method was used to treat the different charges with creosote preservative. For all the charges the same treatment schedule was maintained. Creosote penetration was highest in 14m poles (20.5mm) and lowest in 9m poles (18.4mm), Creosote retention was also highest in 14m poles (193kgm-3), but lowest in 11m poles (162kgm-3). Irrespective of differences in level of penetration and retention among the various pole sizes, all the poles acquired more than the required standard minimum level of penetration and retention i.e. 15mm and 115kgm-3 respectively. However, for all the pole sizes, creosote penetration was less than the sapwood depth. The current treatment schedule seems better suited for the larger poles of 14m than the 9 and 11m. For better treatment, it is recommended that smaller poles i.e. 9m and 11m should be treated for a longer period than 14m poles since they tend to have lager sapwood. The minimum basis of 15mm penetration should be increased to at least cover the entire pole sapwood depth.

Telephone Transmission and Earwitnesses: Performance on Voice Parades Controlled for Voice Similarity

The effect of telephone transmission on a listener's ability to recognise a speaker in a voice parade is investigated. A hundred listeners (25 per condition) heard 1 of 5 ‘target' voices, then returned a week later for a voice parade. The 4 conditions were: target exposure and parade both at studio quality; exposure and parade both at telephone quality; studio exposure with telephone parade, and vice versa. Fewer correct identifications followed from telephone exposure and parade (64%) than from studio exposure and parade (76%). Fewer still resulted for studio exposure/telephone parade (60%) and, dramatically, only 32% for telephone exposure/studio parade. Certain speakers were identified more readily than others across all conditions. Confidence ratings reflected this effect of speaker, but not the effect of exposure/parade condition.

E-therapy: The Ethics Behind the Process

Abstract E-therapy is a new form of counselling that is arising the last years. E-therapy, cyber therapy, webcounseling, and Internet counselling are often used interchangeably. The question that arises on the ethical dilemmas since the licensing laws have not yet caught up with the rapid pace of technology. The salient ethical dimensions of e-therapy include competence, credentialing, informed consent, exceptions to confidentiality, as well as privacy and security limits (Corey, Corey, & Callanan, 2007). The informed consent (written and verbal) including the potential risks, consequences and benefits of telemedicine, or competence to practice, confidentiality, doing no harm, and on how terminations, interruption of service and payment arrangements need to be discussed. In addition, when using these technologies, it's important to conduct an initial assessment of each client to determine his or her appropriateness for telepsychology. Other factors to consider include making sure you have provided adequate emergency contact information in case your distance client faces a crisis, and ensuring that your patient's privacy and confidentiality are adequately protected by encrypting electronic transmissions and records. Furthermore the APA “Ethics Code applies to these activities across a variety of contexts, such as in person, postal, telephone, internet, and other electronic transmissions” (p. 1061). In other words, the ethical standards contain language designed for psychologists who provide services in person, via electronic media, or by other forms of communication.

A novel redundant haar lifting wavelet analysis based fault detection and location technique for telephone transmission lines

The redundant lifting scheme is a perfect tool for wavelet decomposition and reconstruction conducted in the time domain without decimation procedure. In this paper based on the redundant haar lifting wavelet analysis and time domain reflectometry (RHLW-TDR) a novel fault detection scheme is introduced to detect the fault of the telephone transmission lines. The fault time tags are extracted directly from the wavelet detail coefficients. Furthermore, the proposed algorithm is improved to adaptive morphological redundant haar lifting wavelet analysis based time domain reflectometry (AMRHLW-TDR). Comparing to the conventional wavelet based TDR technique, the simulation test and practical experiment results verified the accuracy and convenience enhancement of the proposed methodology and its improved version.

Effects of the telephone on perceived voice similarity: implications for voice line-ups

This study is relevant to forensic cases where an earwitness claims to be able to remember and identify a voice, and, more generally, to voice recognition. Given that a voice may have been heard over the telephone, it is important to know the effects of the telephone on voice quality. In particular we may ask whether the perceptual distance between two voice samples is affected by telephone transmission. In this paper the effects of the telephone are tested by an experiment using fifteen speakers of Standard Southern British English from the DyViS database of accent-matched young adult male speakers. For each possible pairing of speakers (including same-same pairs) twenty listeners heard a short speech sample from each of the two speakers and were asked to rate the distance between the two voices on a scale of 1 (very similar) to 9 (very different). The speech samples had been recorded simultaneously in both studio and telephone quality and were heard in ‘studio only’, ‘telephone only’, and ‘mixed (telephone and studio)’ pairs. Average similarity ratings across all speaker pairings for the three media conditions showed that the same pairs of voices are judged to be more similar when recorded over the telephone than at full bandwidth. When presentation qualities are mixed the voices sound more different for the listener; it is likely that the different transmission characteristics are being conflated with the voice differences. Implications for forensic cases are discussed.

Efectividad y seguridad de la monitorización a distancia de los pacientes portadores de Holter insertable

Introduction and objectivesImplantable loop recorders have proven efficacy in the study of patients with syncope and palpitations. Remote monitoring of patients with pacemakers and implantable cardioverter-defibrillators has been shown to be safe and effective. The purpose of this study was to analyze the safety and effectiveness of remote monitoring in patients with an implantable loop recorder. MethodsRetrospective observational study in which 109 patients with an implantable loop recorder were analyzed and 2 population groups were compared: 1 receiving conventional follow-up consisting of 3-monthly office visits (41 patients) and 1 with remote monitoring via monthly telephone transmissions and yearly visits (68 patients). The mean follow-up was 64 weeks (range, 0.57-164.57 weeks). The study analyzed diagnosis of a significant event, defined as any event that led to a therapeutic approach and explained the symptoms leading to the implant, as well as the mean time from implant to diagnosis and the specific treatment. ResultsA significant event was diagnosed in 82.6% of patients; of these, 54.4% had a normal electrocardiogram; 26.7%, asystole; 15.6%, tachycardia, and 3.3%, bradycardia. The mean time from implant to diagnosis was 260 days (range, 5-947 days) in conventional follow-up, compared with 56 days (range, 0-650 days) in patients with remote monitoring (P<.01), which led to targeted treatment in this group 187 days earlier, on average, with no secondary complications. ConclusionsRemote monitoring of patients with an implantable loop recorder can significantly shorten the time to diagnosis and targeted treatment, without adversely affecting patient safety.Full English text available from:www.revespcardiol.org/en

Effectiveness and Safety of Remote Monitoring of Patients With an Implantable Loop Recorder

Introduction and objectivesImplantable loop recorders have proven efficacy in the study of patients with syncope and palpitations. Remote monitoring of patients with pacemakers and implantable cardioverter-defibrillators has been shown to be safe and effective. The purpose of this study was to analyze the safety and effectiveness of remote monitoring in patients with an implantable loop recorder. MethodsRetrospective observational study in which 109 patients with an implantable loop recorder were analyzed and 2 population groups were compared: 1 receiving conventional follow-up consisting of 3-monthly office visits (41 patients) and 1 with remote monitoring via monthly telephone transmissions and yearly visits (68 patients). The mean follow-up was 64 weeks (range, 0.57-164.57 weeks). The study analyzed diagnosis of a significant event, defined as any event that led to a therapeutic approach and explained the symptoms leading to the implant, as well as the mean time from implant to diagnosis and the specific treatment. ResultsA significant event was diagnosed in 82.6% of patients; of these, 54.4% had a normal electrocardiogram; 26.7%, asystole; 15.6%, tachycardia, and 3.3%, bradycardia. The mean time from implant to diagnosis was 260 days (range, 5-947 days) in conventional follow-up, compared with 56 days (range, 0-650 days) in patients with remote monitoring (P<.01), which led to targeted treatment in this group 187 days earlier, on average, with no secondary complications. ConclusionsRemote monitoring of patients with an implantable loop recorder can significantly shorten the time to diagnosis and targeted treatment, without adversely affecting patient safety.

Speech perception and communication ability over the telephone by Mandarin-speaking children with cochlear implants

Objective(1) To understand speech perception and communication ability through real telephone calls by Mandarin-speaking children with cochlear implants and compare them to live-voice perception, (2) to report the general condition of telephone use of this population, and (3) to investigate the factors that correlate with telephone speech perception performance. MethodsFifty-six children with over 4 years of implant use (aged 6.8–13.6 years, mean duration 8.0 years) took three speech perception tests administered using telephone and live voice to examine sentence, monosyllabic-word and Mandarin tone perception. The children also filled out a questionnaire survey investigating everyday telephone use. Wilcoxon signed-rank test was used to compare the scores between live-voice and telephone tests, and Pearson's test to examine the correlation between them. ResultsThe mean scores were 86.4%, 69.8% and 70.5% respectively for sentence, word and tone recognition over the telephone. The corresponding live-voice mean scores were 94.3%, 84.0% and 70.8%. Wilcoxon signed-rank test showed the sentence and word scores were significantly different between telephone and live voice test, while the tone recognition scores were not, indicating tone perception was less worsened by telephone transmission than words and sentences. Spearman's test showed that chronological age and duration of implant use were weakly correlated with the perception test scores. The questionnaire survey showed 78% of the children could initiate phone calls and 59% could use the telephone 2 years after implantation. ConclusionImplanted children are potentially capable of using the telephone 2 years after implantation, and communication ability over the telephone becomes satisfactory 4 years after implantation.

Effects of telephone transmission on the performance of formant-trajectory-based forensic voice comparison – Female voices

In forensic-voice-comparison casework a common scenario is that the suspect’s voice is recorded directly using a microphone in an interview room but the offender’s voice is recorded via a telephone system. Acoustic-phonetic approaches to forensic voice comparison often include analysis of vowel formants, and the second formant is often assumed to be relatively robust to telephone-transmission effects. This study assesses the effects of telephone transmission on the performance of formant-trajectory-based forensic-voice-comparison systems. The effectiveness of both human-supervised and fully-automatic formant tracking is investigated. Human-supervised formant tracking is generally considered to be more accurate and reliable but requires a substantial investment of human labor. Measurements were made of the formant trajectories of /iau/ tokens in a database of recordings of 60 female speakers of Chinese using one human-supervised and five fully-automatic formant trackers. Measurements were made under high-quality, landline-to-landline, mobile-to-mobile, and mobile-to-landline conditions. High-quality recordings were treated as suspect samples and telephone-transmitted recordings as offender samples. Discrete cosine transforms (DCT) were fitted to the formant trajectories and likelihood ratios were calculated on the basis of the DCT coefficients. For each telephone-transmission condition the formant-trajectory system was fused with a baseline mel-frequency cepstral-coefficient (MFCC) system, and performance was assessed relative to the baseline system. The systems based on human-supervised formant measurement always outperformed the systems based on fully-automatic formant measurement; however, in conditions involving mobile telephones neither the former nor the latter type of system provided meaningful improvement over the baseline system, and even in the other conditions the high cost in skilled labor for human-supervised formant-trajectory measurement is probably not warranted given the relatively good performance that can be obtained using other less-costly procedures.

Intra- and inter-speaker variability in duration and spectral properties of English /s/

This study investigates the speaker-specificity of acoustic characteristics of the English fricative /s/ and contributes background population statistics for use in forensic speaker comparison work. The intra- and inter-speaker variability in duration and spectral properties of /s/ was investigated in data from 30 young adult male speakers of Cambridge and Leeds English. Read speech was used in the present study to allow direct comparison across speakers. Segment duration was normalized for speaking rate. Spectra were filtered at 4 kHz in order to explore speaker discrimination performance at settings mimicking the bandpass filter effect of telephone transmission. Additional filters were applied at 8, 16, and 22.05 kHz to investigate discrimination with data from various frequency ranges. Spectral measures were calculated from a 40-ms window centered on the midpoint of each token. Although mean values display relatively little inter-speaker variation, the individuals at the extreme high and low ends of the distributions may be the best discriminated, particularly those at the extremes on more than one parameter. Discriminant analyses were conducted to determine the most speaker-specific predictors; relative performance was compared across the four filter conditions. The discriminatory ability of these parameters will also be presented using a likelihood ratio framework.

The telecardiology revolution: improving the management of cardiac disease in primary care.

Telecardiology allows for the remote specialist interpretation of electrocardiographic recordings via telephone transmission. It has the potential to change the way cardiac care is being delivered in the primary care setting. This review discusses the current status of cardiac care in the community, and highlights how telecardiology can help support general practitioners in the diagnosis and management of acute and chronic cardiac disease, as well as provide the potential for screening opportunities in particular patients at risk. Also reviewed is the success of recent trials of a telecardiology service in the north west of England. Thanks to developments in technology and ever decreasing costs, telecardiology has the potential to save time, money and lives. Telecardiology, it would seem, is set to revolutionize cardiac care in the community, making savings and bridging the gap between primary and secondary care.

ECG QRS Enhancement Using Artificial Neural Network

Soft computing is a new approach to construct intelligent systems. The complex real world problems require intelligent systems that combine knowledge, techniques and methodologies from various sources. Neural networks recognize patterns and adapt themselves to cope with changing environments. Artificial neural network has potential applications in the field of ECG diagnosis measures. So noise reduced QRS complex of ECG signal is of utmost importance for automatic ECG interpretation and analysis. Noise is an unwanted energy, which interferes with the desired signal. Noise cancellation is mainly used as interference canceling in ECG, echo elimination on long distance telephone transmission lines and antenna side lobe interference canceling. In the study, the ECG signal is trained following various artificial neural network based algorithms to enhance the QRS complex by reducing noise for further analysis.