Fourth Aircraft Interior Noise Workshop

The fourth in a series of NASA/SAE Interior Noise Workshops was held on May 19 and 20, 1992. The theme of the workshop was new technology and applications for aircraft noise with emphasis on source noise prediction; cabin noise prediction; cabin noise control, including active and passive methods; and cabin interior noise procedures. This report is a compilation of the presentations made at the meeting which addressed the above issues

Suivi Multi-Locuteurs avec des Informations Audio-Visuelles pour la Perception des Robots

Robot perception plays a crucial role in human-robot interaction (HRI). Perception system provides the robot information of the surroundings and enables the robot to give feedbacks. In a conversational scenario, a group of people may chat in front of the robot and move freely. In such situations, robots are expected to understand where are the people, who are speaking, or what are they talking about. This thesis concentrates on answering the first two questions, namely speaker tracking and diarization. We use different modalities of the robot’s perception system to achieve the goal. Like seeing and hearing for a human-being, audio and visual information are the critical cues for a robot in a conversational scenario. The advancement of computer vision and audio processing of the last decade has revolutionized the robot perception abilities. In this thesis, we have the following contributions: we first develop a variational Bayesian framework for tracking multiple objects. The variational Bayesian framework gives closed-form tractable problem solutions, which makes the tracking process efficient. The framework is first applied to visual multiple-person tracking. Birth and death process are built jointly with the framework to deal with the varying number of the people in the scene. Furthermore, we exploit the complementarity of vision and robot motorinformation. On the one hand, the robot’s active motion can be integrated into the visual tracking system to stabilize the tracking. On the other hand, visual information can be used to perform motor servoing. Moreover, audio and visual information are then combined in the variational framework, to estimate the smooth trajectories of speaking people, and to infer the acoustic status of a person- speaking or silent. In addition, we employ the model to acoustic-only speaker localization and tracking. Online dereverberation techniques are first applied then followed by the tracking system. Finally, a variant of the acoustic speaker tracking model based on von-Mises distribution is proposed, which is specifically adapted to directional data. All the proposed methods are validated on datasets according to applications.La perception des robots joue un rôle crucial dans l’interaction homme-robot (HRI). Le système de perception fournit les informations au robot sur l’environnement, ce qui permet au robot de réagir en consequence. Dans un scénario de conversation, un groupe de personnes peut discuter devant le robot et se déplacer librement. Dans de telles situations, les robots sont censés comprendre où sont les gens, ceux qui parlent et de quoi ils parlent. Cette thèse se concentre sur les deux premières questions, à savoir le suivi et la diarisation des locuteurs. Nous utilisons différentes modalités du système de perception du robot pour remplir cet objectif. Comme pour l’humain, l’ouie et la vue sont essentielles pour un robot dans un scénario de conversation. Les progrès de la vision par ordinateur et du traitement audio de la dernière décennie ont révolutionné les capacités de perception des robots. Dans cette thèse, nous développons les contributions suivantes : nous développons d’abord un cadre variationnel bayésien pour suivre plusieurs objets. Le cadre bayésien variationnel fournit des solutions explicites, rendant le processus de suivi très efficace. Cette approche est d’abord appliqué au suivi visuel de plusieurs personnes. Les processus de créations et de destructions sont en adéquation avecle modèle probabiliste proposé pour traiter un nombre variable de personnes. De plus, nous exploitons la complémentarité de la vision et des informations du moteur du robot : d’une part, le mouvement actif du robot peut être intégré au système de suivi visuel pour le stabiliser ; d’autre part, les informations visuelles peuvent être utilisées pour effectuer l’asservissement du moteur. Par la suite, les informations audio et visuelles sont combinées dans le modèle variationnel, pour lisser les trajectoires et déduire le statut acoustique d’une personne : parlant ou silencieux. Pour experimenter un scenario où l’informationvisuelle est absente, nous essayons le modèle pour la localisation et le suivi des locuteurs basé sur l’information acoustique uniquement. Les techniques de déréverbération sont d’abord appliquées, dont le résultat est fourni au système de suivi. Enfin, une variante du modèle de suivi des locuteurs basée sur la distribution de von-Mises est proposée, celle-ci étant plus adaptée aux données directionnelles. Toutes les méthodes proposées sont validées sur des bases de données specifiques à chaque application

Development of a software for panoramic video and audio recordings with microphone arrays

Dense microphones array is certainly one of the most promising technology not only for environmental noise analysis, but also for 3D audio recordings, where 3D stands for a complete spatial description of the event recorded. During last years at the Industrial Engineering Department of Università degli Studi di Parma (IED) with the collaboration of the spinoff AIDA srl., a new meta-theory was developed that provides a framework capable of representing all the known microphones array, based on the model of Virtual Microphones. The strict collaboration with the Centro Ricerca ed Innovazione Tecnologica (CRIT, Research Center and Technology Innovation) of RAI, the national Italian television broadcasting company, quickly individuates some key applications of this technology that conduct to the realization of some ad-hoc dense arrays and of a software to manage all the acquisition and post-processing system. In this PhD thesis work a detailed description of the software, named 3D VMS, will be given, preceded by an introduction about the current state of the art of this technology.Sviluppo di array planari di microfoni e dell'HW/SW necessario per un'applicazione alla manutenzione predittiva delle macchin

Video Conferencing Technology for Distance Learning in Saudi Arabia: Current Problems, Feasible Solutions and Developing an Innovative Interactive Communication System based on Internet and wifi Technology for Communication Enhancement

Context: In Saudi Arabia, distance-learning plays a vital role in the female higher education system. This system is considered unique among all the world’s countries because, for religious reasons, intermixing of the genders is not allowed within most educational settings in Saudi society. This system is currently facing a problem with an overflow of female students in higher educational institutions as these institutions suffer from a lack of female faculty members. To resolve this problem, all universities in Saudi Arabia utilise synchronous distance learning technologies such as video and audio conferences technologies for the delivery of subjects by male faculty members to female students, as this is the only authorised way for male faculty to teach female students. Although this method has been used in Saudi Arabia continuously since 1970, no study has addressed the perceptions of female students, regarding the problems they face whilst studying, through such technologies or proposed any solution for these problems. Aim: The purpose of this study is to identify the perceptions of female students at King Saud University regarding the difficulties and barriers they encounter in the distance learning classrooms that use video conferencing technology. This study also proposes feasible solutions for the most common problems. It has developed an innovative interactive communication system, CommEasy, based on the internet and Wi-Fi technologies for handheld devices and uses this system to enhance communication and participation in distance learning. Method: The research questions are answered by applying a mixture of quantitative and qualitative approaches that have been selected according to the nature of the research. A case study research design was chosen to address all the research questions related to KSU. Identifying the perceptions of female students about the problems they encounter in distance learning classrooms was gathered through a questionnaire with five main parts: classroom physical design, classroom physical features, technical support, communication and participation with male instructors and classroom management. Each part used a number of questions to measure the students' perceptions and the students were asked to respond to each question using a five-point Likert scale. Proposing feasible solutions for the problems reported by students required using a mixture of methods, such as observations, structured interviews and surveys. An incremental software development approach was used to develop the CommEasy tool that was used in this thesis and the quasi-experimental method was used to evaluate this tool in the actual learning environment. Results: The results of the thesis presented the perceptions of students towards the components of the distance-learning classrooms and showed all the satisfactory and unsatisfactory components. It produced a list of strategies for effective designing of the distance-learning classroom that uses video conference technology, produced a new physical design for the distance-learning classrooms that used video conference technologies, provided a set of feasible solutions for the problems identified and finally, showed that the CommEasy system has a positive impact, in supporting communication in the distance-learning classroom, leading to an increased level of student participation with instructors, as well as solving most of the problems students were faced with in this regard. Conclusions: in summary, the outcome of this thesis should provide both researchers and decision makers with an insight into the problems facing students in distance-learning, as well as providing them with feasible solutions for these problems. This thesis will serve as a basis for further research in this field to be conducted in Saudi Arabia

New Procedure For Loudness Assesment and Noise Attenuation of Ventilation Kitchen Range Hoods

The Home Ventilating Institute (HVI) created a standard to specify the procedure for sound quality testing of mechanical ventilation equipment. This standard contained a procedure for performance, reliability, and accuracy based on a full assembly loudness assessment. This thesis provides a new generic component loudness assessment procedure that can be utilized to identify and reduce the noise radiating from kitchen range hoods based on an individual component loudness assessment. With these evaluations, design improvements are implemented to help reduce the outgoing noise from the range hood that may cause hearing loss or high stress. Four different range hoods were tested across the 24-1/3 octave frequency bands using the new component loudness assessment procedure. The kitchen range hoods tested include two centrifugal-flow fans and two axial-flow fans for ventilation. Each range hood includes basic component design differences in the damper, grille, and enclosure. The results show that in all but one case the damper caused an increase in the overall loudness by 10% at high speed and as much as 70% at low speed. In addition it has been observed that the addition of the grille can either reduce the loudness or increase the loudness depending on design features. Using the information gathered from the component loudness assessment, practical low-cost noise attenuation techniques are formulated and implemented in order to reduce overall loudness. The primary goal of noise attenuation (or noise reduction) is to diminish the overall loudness to a comfortable level. Using the techniques formulated, vibration and aerodynamic induced noise have been reduced across all speeds of the range hood by as much as 15%. The greatest reduction was observed at high speed with a reduction of 2.17 sones, while mid and low speed were able to archive a reduction of 0.89 sones and 1 sone respectively. The new procedure gives improved insight into individual components contribution to overall loudness, and provides better intuition on how to reduce the outgoing noise. A reduction in noise should improve the sound quality indoors and have a positive effect on consumer health and quality of life

Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Proceedings of the EAA Spatial Audio Signal Processing symposium: SASP 2019

International audienc

Sound Localization by Echolocating Bats

Echolocating bats emit ultrasonic vocalizations and listen to echoes reflected back from objects in the path of the sound beam to build a spatial representation of their surroundings. Important to understanding the representation of space through echolocation are detailed studies of the cues used for localization, the sonar emission patterns and how this information is assembled. This thesis includes three studies, one on the directional properties of the sonar receiver, one on the directional properties of the sonar transmitter, and a model that demonstrates the role of action in building a representation of auditory space. The general importance of this work to a broader understanding of spatial localization is discussed. Investigations of the directional properties of the sonar receiver reveal that interaural level difference and monaural spectral notch cues are both dependent on sound source azimuth and elevation. This redundancy allows flexibility that an echolocating bat may need when coping with complex computational demands for sound localization. Using a novel method to measure bat sonar emission patterns from freely behaving bats, I show that the sonar beam shape varies between vocalizations. Consequently, the auditory system of a bat may need to adapt its computations to accurately localize objects using changing acoustic inputs. Extra-auditory signals that carry information about pinna position and beam shape are required for auditory localization of sound sources. The auditory system must learn associations between extra-auditory signals and acoustic spatial cues. Furthermore, the auditory system must adapt to changes in acoustic input that occur with changes in pinna position and vocalization parameters. These demands on the nervous system suggest that sound localization is achieved through the interaction of behavioral control and acoustic inputs. A sensorimotor model demonstrates how an organism can learn space through auditory-motor contingencies. The model also reveals how different aspects of sound localization, such as experience-dependent acquisition, adaptation, and extra-auditory influences, can be brought together under a comprehensive framework. This thesis presents a foundation for understanding the representation of auditory space that builds upon acoustic cues, motor control, and learning dynamic associations between action and auditory inputs