Estudio acústico y electroacústico de la sala 18 de Kinépolis (Madrid)

El objetivo de este proyecto se materializa en el diseño acústico y electroacústico de las salas de cine con número 18, 19, 20 y 21 del centro de cines Kinépolis situado en la Ciudad de la Imagen. Dichas salas son idénticas por lo que con el estudio y análisis de una se podrán extrapolar los resultados a las demás, por tanto a partir de ahora se realizará el diseño acústico y electroacústico centrado en la sala 18. Así pues se procederá a certificar que dicha sala cumple la norma THX. En dicho recinto se habrán aplicando con anterioridad diferentes técnicas de acondicionamiento sonoro (insonorización mediante el uso de materiales tanto absorbentes como reflectantes, arquitectura de la sala ), así como todos los acondicionamientos propios de un espacio de uso público cumpliendo las consiguientes normativas de seguridad. Se analizará la sala en su estado de partida mediante medidas acústicas in-situ tanto del tiempo de reverberación como del ruido de fondo, así como medidas espaciales con un medidor de alta precisión (láser); para posteriormente realizar las simulaciones en el programa EASE 4.01 de manera que la simulación sea lo más fidedigna posible. Estas medidas se realizarán de acuerdo a lo especificado en la norma UNE-EN ISO 3382. Cuando el comportamiento acústico del modelado de la sala sea el mismo que el de la sala real (respondan con el mismo Tiempo de Reverberación), mediante la introducción de los materiales adecuados y del ruido de fondo; se procederá al diseño electroacústico del equipo necesario para implementar el sistema de sonido multicanal Dolby (R). En el estudio electroacústico se distribuirán los diferentes altavoces que correctamente insertados ajustados sus niveles y retardos cubrirán con su señal uniformemente la sala cumpliendo los requisitos de la norma Dolby (R). Y finalmente una vez propuesto el sistema electroacústico y comprobado su correcto funcionamiento y por tanto el cumplimiento de la norma THX se propondrán mejoras en el sistema. Hay que señalar que aunque las recomendaciones THX son conocidas como norma THX no es una norma como tal, sino un conjunto de recomendaciones, que aconsejan utilizar una norma u otra para cada requisito. De ahora en adelante se referirá en este documento como norma THX. Se recuerda una vez más que dado que las salas son idénticas, y que las medidas realizadas en cada una de ellas son similares, se procederá en adelante al estudio de la sala única sala, la sala 18, siendo todos los estudios, análisis, comentarios y conclusiones aplicables a las otras 3 salas. Abstract The aim of this Project is the acoustic and electroacoustic design of the projection rooms 18th, 19th, 20th and 21st of the theater kinépolis, which is located at “Ciudad de la imagen”. These rooms are equal so with the studing and analazing of one of them , the results can be extrapolted from this one to the others, therefore as from now the and electroacoustic design will focus on the 18th room. As result the room will be certified that it comply with the standard THX. The starting point of the room will be analized such on-spot acoustical measures as the reverberation time and the noise level, in the same way the spatial measurements will be make with a precise laser meter, in order to perform simulations with the data obtained with the EASE 4.01 program. These mesurements should be made in accordance with the standard UNE-EN ISO 3382. Once the acoustical behavior of the simulated room became the same as the real room (the same reverberation times), through the configuration of the suitable materials and the background noise, previously measured, the electroacoustic design of the equipment necessary to develop the multichannel sound system Dolby (R) will be completed. In the electroacoustic design the sound power level and the dealys of the speakers and its amplifiers will be configurated till amplifiers provide an uniform coverage over the entire room in compliance with the Dolby (R) standard. Finally, once an electroacoustic system will be proposed and checked it works correctly in compliance with the THX standard, posible improvements will be identified. Abstract. Acoustic and electroacoustic study of the 18th room of the movie theater Kinépolis (Madrid) It must however be pointed out that although the THX standard is known as a standard it is actually a set of recommended practices made by Lucasfilm Ltd, anyway, from now on we will call it THX standard.

Relationship between objective and subjective indicators in urban soundscape analysis. The case of Cordoba - Argentina

This paper presents the main results of a comparative evaluation of some acoustical parameters with the user´s perception of urban sounds. The study was carried out in three open spaces integrated with different environmental characteristics but similar objective conditions of urban noise. The subjective evaluation was done by means of a survey simultaneously with the objective measurements. The results of the crossed analysis confirmed that in environments with similar noise levels not always exists direct correlation between the objetive indicators and the acoustic comfort of the people. To predict the acustical quality of the soundscape it is necessary to consider aspects such as the background noise and the perception of natural or technological sounds as complements of the general sound level.

Diseño acústico y electroacústico de Waipahu Transit Center en Honolulú, Hawái

El objetivo de este Proyecto Fin de Grado es el diseño de megafonía y PAGA (Public Address /General Alarm) de la estación de tren Waipahu Transit Center en la ciudad de Honolulú, Hawái. Esta estación forma parte de una nueva línea de tren que está en proceso de construcción actualmente llamada Honolulu Rail Transit. Inicialmente la línea de tren constará de 21 estaciones, en las que prácticamente todas están diseñadas como pasos elevados usando como referencia las autopistas que cruzan la isla. Se tiene prevista su fecha de finalización en el año 2019, aunque las primeras estaciones se inaugurarán en 2017. Se trata en primer lugar un estudio acústico del recinto a sonorizar, eligiendo los equipos necesarios: conmutadores, altavoces, amplificadores, procesador, equipo de control y micrófonos. Este primer estudio sirve para obtener una aproximación de equipos necesarios, así como la posible situación de estos dentro de la estación. Tras esto, se procede a la simulación de la estación mediante el programa de simulación acústica y electroacústica EASE 4.4. Para ello, se diseña la estación en un modelo 3D, en el que cada superficie se asocia a su material correspondiente. Para facilitar el diseño y el cómputo de las simulaciones se divide la estación en 3 partes por separado. Cada una corresponde a un nivel de la estación: Ground level, el nivel inferior que contiene la entrada; Concourse Level, pasillo que comunica los dos andenes; y Platform Level, en el que realizarán las paradas los trenes. Una vez realizado el diseño se procede al posicionamiento de altavoces en los diferentes niveles de la estación. Debido al clima existente en la isla, el cual ronda los 20°C a lo largo de todo el año, no es necesaria la instalación de sistemas de aire acondicionado o calefacción, por lo que la estación no está totalmente cerrada. Esto supone un problema al realizar las simulaciones en EASE, ya que al tratarse de un recinto abierto se deberán hallar parámetros como el tiempo de reverberación o el volumen equivalente por otros medios. Para ello, se utilizará el método Ray Tracing, mediante el cual se halla el tiempo de reverberación por la respuesta al impulso de la sala; y a continuación se calcula un volumen equivalente del recinto mediante la fórmula de Eyring. Con estos datos, se puede proceder a calcular los parámetros necesarios: nivel de presión sonora directo, nivel de presión sonora total y STI (Speech Transmission Index). Para obtener este último será necesario ecualizar antes en cada uno de los niveles de la estación. Una vez hechas las simulaciones, se comprueba que el nivel de presión sonora y los valores de inteligibilidad son acordes con los requisitos dados por el cliente. Tras esto, se procede a realizar los bucles de altavoces y el cálculo de amplificadores necesarios. Se estudia la situación de los micrófonos, que servirán para poder variar la potencia emitida por los altavoces dependiendo del nivel de ruido en la estación. Una vez obtenidos todos los equipos necesarios en la estación, se hace el conexionado entre éstos, tanto de una forma simplificada en la que se pueden ver los bucles de altavoces en cada nivel de la estación, como de una forma más detallada en la que se muestran las conexiones entre cada equipo del rack. Finalmente, se realiza el etiquetado de los equipos y un presupuesto estimado con los costes del diseño del sistema PAGA. ABSTRACT. The aim of this Final Degree Project is the design of the PAGA (Public Address / General Alarm) system in the train station Waipahu Transit Center in the city of Honolulu, Hawaii. This station is part of a new rail line that is currently under construction, called Honolulu Rail Transit. Initially, the rail line will have 21 stations, in which almost all are designed elevated using the highways that cross the island as reference. At first, it is treated an acoustic study in the areas to cover, choosing the equipment needed: switches, loudspeakers, amplifiers, DPS, control station and microphones. This first study helps to obtain an approximation of the equipments needed, as well as their placement inside the station. Thereafter, it is proceeded to do the simulation of the station through the acoustics and electroacoustics simulation software EASE 4.4. In order to do that, it is made the 3D design of the station, in which each surface is associated with its material. In order to ease the design and calculation of the simulations, the station has been divided in 3 zones. Each one corresponds with one level of the station: Ground Level, the lower level that has the entrance; Concourse Level, a corridor that links the two platforms; and Platform Level, where the trains will stop. Once the design is made, it is proceeded to place the speakers in the different levels of the station. Due to the weather in the island, which is about 20°C throughout the year, it is not necessary the installation of air conditioning or heating systems, so the station is not totally closed. This cause a problem when making the simulations in EASE, as the project is open, and it will be necessary to calculate parameters like the reverberation time or the equivalent volume by other methods. In order to do that, it will be used the Ray Tracing method, by which the reverberation time is calculated by the impulse response; and then it is calculated the equivalent volume of the area with the Eyring equation. With this information, it can be proceeded to calculate the parameters needed: direct sound pressure level, total sound pressure level and STI (Speech Transmission Index). In order to obtain the STI, it will be needed to equalize before in each of the station’s levels. Once the simulations are done, it is checked that the sound pressure level and the intelligibility values agree with the requirements given by the client. After that, it is proceeded to perform the speaker’s loops and the calculation of the amplifiers needed. It is studied the placement of the microphones, which will help to vary the power emitted by the speakers depending on the background noise level in the station. Once obtained all the necessary equipment in the station, it is done the connection diagram, both a simplified diagram in which there can be seen the speaker’s loops in each level of the station, or a more detailed diagram in which it is shown the wiring between each equipment of the rack. At last, it is done the labeling of the equipments and an estimated budget with the expenses for the PAGA design.

Caracterización de ambientes sonoros en recintos universitarios: influencia del ruido sobre procesos cognitivos básicos

El interés por el estudio de la problemática del ruido en las escuelas y sus efectos sobre los estudiantes a nivel universitarios, es un tema que no ha sido estudiado debidamente. Desgraciadamente, en el ámbito educativo universitario, no existen regulaciones específicas que permitan determinar parámetros preventivos, ni procedimientos de evaluación de ruido dentro de este tipo de instalaciones educativas. Debido a la importancia de los efectos que el ruido tiene sobre la salud y la calidad de vida de los estudiantes universitarios, y consecuentemente en el rendimiento académico; es de suma importancia desarrollar mecanismos que estudien y planteen soluciones que ayuden a garantizar la mejora de la calidad de vida de la población estudiantil. En este trabajo se ha presentado un extenso trabajo que incluye el estudio de los ambientes sonoros a los que los estudiantes universitarios se ven expuestos día a día y se proponen acciones que ayudan a mejorar la calidad acústica en instalaciones educativas. Así mismo se evidencian los efectos que tiene este contaminante sobre la salud psicológica y por consecuencia en el desarrollo intelectual de los estudiantes. Por un lado, se incluye una propuesta de metodología que ayuda a la correcta caracterización de los ambientes sonoros en los cuales se desarrollan los estudiantes a nivel universitario. Esta se realizó haciendo un completo registro de los niveles sonoros durante sus actividades diarias. Así mismo, una encuesta fue aplicada a estudiantes para conocer la percepción que se tiene sobre las condiciones sonoras en ambientes universitarios. Así mismo, se realizó un estudio de la calidad sonora en instalaciones universitarias, el cual deriva la valoración de la molestia al ruido. Se propone una escala de valoración de molestia al ruido, la cual deriva el diseño de una propuesta con acciones de bajo coste frente al ruido. Por otro lado, se evidencian los trastornos que ocasiona este contaminante sobre la salud psicológica de los estudiantes y que afectan el desarrollo académico de estos. Se realizó primeramente la valoración de la atención y la memoria por medio de test psicométricos estandarizados y otros diseñados para este estudio en particular. Por último, con la finalidad de obtener datos objetivos y confiables que permitieron relacionar la influencia negativa del ruido de fondo sobre procesos cognitivos básicos como la atención y la memoria, se llevó a cabo un estudio de la actividad cerebral. Para llevar a cabo esta evaluación se utilizó como principal herramienta el electroencefalograma (EEG), enfocándose en los cambios producidos con y sin exposición a ruido de fondo, específicamente en las bandas de frecuencia relacionadas con procesos cognitivos básicos como los son la atención y la memoria, en este caso la banda theta (4-7 Hz) y la banda beta (13-30 Hz). ABSTRACT The interest in the study of the problem of noise in schools and its impact on students at university level is a topic that has not been properly studied. Unfortunately, there are no specific regulations for determining preventive parameters or noise assessment procedures in university facilities. Due to the importance of the effects that noise has on health and on the quality of life of university students, and consequently on academic performance; is very important to develop mechanisms to evaluate and design solutions that help ensure an improvement in the quality of life of the student population. This thesis has presented an extensive work, which includes the study of the state of the art on the problem of noise in the sound environments to which university students are exposed every day, and the effects on students mainly on attention aspects. On one hand, a general study of the common noise environments of life of university students was carried out, where a methodological proposal is included and that helps in the correct characterization of the sound environments in which university students grow. This proposal includes the assessment of noise exposure, noise dose and a recording of the characteristic sound levels during their daily activities in and out spaces dedicated to their education. Also, a survey was conducted to know the perception that students have on noise conditions in university environments. Also, a method for evaluation of the noise annoyance is proposed, this is through the correlation of two known methods of evaluation. The first method is based on psychoacoustic parameters that allow the evaluation of the sound quality. These parameters were related, obtaining as a result the parameter known as psychoacoustics annoyance. The second method is based on a questionnaire in conjunction with listening tests in specific sound environments. Derived from the correlation of these two methods, a series of indicators of noise annoyance are proposed, which entails the design of a noise annoyance indicator. Furthermore, the effects of this pollutant on psychological health and therefore in the intellectual development of students has been shown. First, an evaluation of attention and memory using standardized psychometric tests were performed and others designed for this particular study. Because it has been evidenced that the use of these psychometric tests are not very reliable, we sought to obtain another objective and reliable data to show the relationship between the negative influence of background noise on basic cognitive processes such as attention and memory. This was achieved by carrying out a study of the brain activity. To carry out this evaluation the electroencephalogram (EEG) was used as the main tool, focusing on the changes produced with and without exposure to background noise, specifically in the frequency bands related to basic cognitive processes such as attention and are memory. In this case the band theta (4-7 Hz) and beta band (13-30 Hz) were studied. The purpose of this thesis is to establish the bases for future studies that allow go deep in the study of the sound conditions in school environments, and enable the design of strategies and measures against noise and the correct evaluation of the effects of noise on aspects for improving the psychological quality of life and academic performance of students.

Aislamiento acústico a ruido aéreo en techos con materiales ecológicos

El incremento de la contaminación acústica se ha convertido en un problema medioambiental lo cual ha generado un aumento en la demanda del aislamiento de los edificios para lograr el confort acústico. Existen métodos de medición de aislamiento acústico a ruido aéreo de fachadas bajo ensayo “in situ” pero no para techos. El objetivo de esta investigación consiste en determinar el aislamiento acústico de prototipos de techos ecológicos multicapas adaptando la metodología recomendada por normas internacionales. Se propusieron cuatro prototipos de techos con distintos materiales naturales como especies vegetales y sustratos de fibra de coco, superpuestos sobre un techo base liviano. Al sustrato se le varió su espesor de 10 a 20 cm, sus condiciones seca o húmeda y su densidad: 100%, 66% y 33% fibra de coco. En los resultados se determinó que las especies vegetales no aportaron aislamiento, pero al incrementar el espesor y densidad del sustrato mejoró el aislamiento sonoro. También se determinó que el aislamiento acústico en condición seca fue mejor que en condición húmeda. Se planteó una metodología para determinar el aislamiento acústico a ruido aéreo en techos bajo ensayo “in situ” empleando el método global con altavoz, ésta se estructuró en tres partes: la primera describe el módulo experimental y la plataforma tecnológica; la segunda aborda procedimientos para medir los niveles de presión sonora, niveles de ruido de fondo y los tiempos de reverberación, en bandas de frecuencia de tercios de octava; en la tercera se explica el cálculo de los promedios de estos parámetros, así como también la diferencia de niveles estandarizada, el índice de reducción sonora aparente con sus valores globales y su incertidumbre. Así mismo, se determinó un algoritmo de predicción del aislamiento acústico, analizando los valores obtenidos en las mediciones “in situ” como la Diferencia de nivel estandarizada ponderada y el Índice ponderado de reducción sonora, los cuales se relacionaron con el peso y el espesor de los materiales de las diferentes multicapas. A través de un análisis de regresión se establecieron modelos para predecir la Diferencia de nivel estandarizada y el Índice de reducción sonora aparente en bandas de octavas. Los resultados del modelo propuesto son cercanos a los datos medidos “in situ”. Por otra parte, se realizaron mediciones térmicas en un módulo experimental y otro de referencia en tres períodos del día. En el módulo experimental se construyeron los prototipos de techos ecológicos y en el de referencia un techo de construcción tradicional, se compararon los resultados de ambos módulos y su interacción con la temperatura exterior. Se detectó que las temperaturas internas del módulo experimental en condición seca tienden a mantener sus valores durante todo el día, en horas de la mañana sus valores son superiores a los del módulo de referencia y temperatura exterior. Al mediodía y en la tarde las temperaturas internas del módulo experimental son inferiores a las del módulo de referencia, incrementándose esta última a medida que aumenta temperatura exterior. Finalmente, a partir de las mediciones “in situ” se realizaron cuatro modelos de correlación acústica-térmica, los tres primeros relacionando la temperatura y el nivel de presión sonora en tres momentos del día, en la tarde se aprecia que a medida que aumenta la temperatura aumentan los niveles de presión sonora. En el cuarto modelo se estableció una correlación acústica-térmica entre la resistencia térmica de los materiales de las multicapas con su índice de reducción sonora, obteniéndose un coeficiente de correlación moderado. La presente investigación plantea retos desde el punto de vista ambiental, permite cuantificar el aislamiento acústico de los techos y mejorar la calidad de vida en áreas urbanas; el empleo de los materiales de procedencia local como los utilizados fomenta el respeto por la naturaleza y producen un menor impacto ambiental. ABSTRACT Sound contamination increase has generated a raise in insulation demand of buildings in order to achieve a sound comfort, and this has become into an environmental problem. There are measurements methods for air borne soundproofing in facades through “in situ” test but there are not for roofs. The purpose of this research is to determine sound insulation of multilayer green roof prototypes following the methodology suggested by international standards. Four prototypes of roofs with different types of vegetation and overlapped coconut fiber substrates over a light roof were proposed. Thickness of substrate varied from 10 to 20 cm, as well as its dry a humid condition and its density: 100%, 66% y 33% of coconut fiber. Results determined that vegetation did not contribute to insulation but when increasing substrate’s thickness and density, sound insulation was improved. Likewise, it was determined that sound insulation in dry condition was greater than in humid condition. A methodology to determine airborne sound insulation in roofs through “in situ” test using a speaker global method was stated. This was structured in three parts: the first part describes the experimental module and the technological platform; the second one establishes the procedures to measure sound pressure levels; levels of background noise and time of reverberation in frequency bands of thirds of octave, and in the third part, averages of these parameters, as well as the difference of standardized levels, the apparent sound reduction with its global values and uncertainty were calculated. Likewise, a prediction algorithm of sound insulation was determined by analyzing values obtained in “in-situ” measures such as the difference of weighted standardized level and the weighted index of sound reduction which they were related to weight and thickness of different multilayer materials. Models to predict the standardized level difference and the apparent sound reduction index in bands of octaves were established by a regression analysis. Results for the proposed model are close to data measured “in situ”. On the other hand, thermal measures were done in an experimental module, as well as in another as for reference in three periods of the day. Green prototypes roofs were built in the experimental module and a traditional roof were built in the reference one. Results of both modules were compared as well as the interaction with outside temperature. Internal temperatures of the experimental module in dry condition tend to keep their values throughout the day; in the morning, its values are higher than those of the reference module and external temperatures. Finally, four models of sound-thermal correlation were done from measures “in situ”. The first three were related to temperature and sound pressure level in three moments of the day. In the afternoon, it is observed that when temperature increases, sound pressure levels increases too. In the fourth model, a sound and thermal correlation was established between thermal resistance of multilayer materials with their sound reduction index, and a moderated correlation coefficient was obtained. This research poses challenges from the environmental point of view, and it allows quantifying sound insulation of roofs as well as improving quality of life in urban areas; the use of local vegetation promotes respect for nature and it produces a smaller environmental impact as well.

Estudio acústico y electroacústico para la realización de un musical en el teatro Rialto de Madrid

El propósito de este Proyecto Fin de Carrera es el estudio acústico y electroacústico de la realización del musical “Hoy no me puedo levantar” en el Teatro Rialto de Madrid en 2005. En primer lugar, se realiza una breve introducción histórica, citando sus remodelaciones y comentando la situación actual del recinto. Posteriormente, es analizado el equipo de sonido empleado en el espectáculo a partir de cada uno de los distintos controles de sonido: FOH (Front of Hause), monitores y microfonía inalámbrica. De cada uno de ellos se explican sus principales funciones y los sistemas que los conforman. También se describe la utilización de las cabinas insonorizadas. A continuación, se detallan los sistemas electroacústicos (empleados en el diseño) de la sonorización de dicho musical, que se consideran divididos en las siguientes partes: sistema principal, refuerzos y retardos, efectos y monitores. Además, se detalla el software RMS (Remote Monitoring System), que aporta información del funcionamiento de estos sistemas en tiempo real. Seguidamente, se exponen el equipo, procedimiento y resultados de la medida in situ en el Teatro, aplicando la Norma UNE-EN ISO 3382-2/2008 para obtener el tiempo de reverberación y ruido de fondo. Con el objeto de inicializar la simulación por ordenador, primero se exportan los planos originales de AutoCAD a EASE 4.4, donde se finaliza el proceso de modelar el recinto. Posteriormente, se asignan materiales, áreas de audiencia, puntos de escucha y se ubican los sistemas electroacústicos. Se afina el tiempo de reverberación obtenido en la medida in situ mediante materiales de la base de datos del propio software. También se ajustan los sistemas electroacústicos en el recinto para obtener la ecualización empleada y los niveles de presión sonora directo y total para distintas frecuencias. Una vez finalizados los pasos anteriores, se procede a realizar estudios psicoacústicos para comprobar posibles ecos y el efecto precedencia (empleando retardos electrónicos o delays). Finalmente, se realizan estudios de inteligibilidad, en los que se justifica la Claridad de Voz (C50) y Claridad Musical (C80); el Índice de inteligibilidad del habla (SII), la Pérdida de articulación de consonantes (Alcons) y el Índice de transmisión del habla (STI). Por último se expone el presupuesto del proyecto y del alquiler del equipo de sonido del musical y se exponen las conclusiones del Proyecto Final de Carrera. ABSTRACT. The purpose of this Final Degree Project is the acoustic and electro-acoustic study of the musical “Hoy No Me Puedo Levantar” at Teatro Rialto in 2005 (Madrid, Spain). First of all, a brief review of its history is made, quoting its refurbishments and discussing the current situation of this enclosure. Later, the sound equipment of the show is analyzed through every different sound controls: FOH (Front Of House), monitors and wireless microphones. There is also an explanation about their principal functions and systems, as well as a description of the soundproof cabins. Then, the electro-acoustic systems are detailed and divided in the following parts: main system, boosters and delays, effects and monitors. The RMS software (Remote Monitoring System) is described too, since it gives relevant information of the systems operations in real time. Afterwards, equipment, procedures and results of the measurements are exposed, applying the UNE-EN ISO 3382-2/2008 regulation in order to obtain the reverberation time and background noise of the theatre. With the purpose of initialize the computer simulation, original plans are exported from AutoCad to EASE 4.4., where its modeling process is ended. Materials, audience areas, hearing points and electro-acoustic locations are assigned below. At the same time, reverberation time is tuned up using database materials of the software itself. Also, electro-acoustic systems of the enclosure are adjusted to get the equalization and pressure sound levels of the different frequencies. Once previous steps are finished, psycho-acoustic studies are made to check possible echoes and the precedence effect - using electronic delays -. Finally, intelligibility studies are detailed, where the Voice and Musical Clarities are justified: The Speech Intelligibility Index, the Loss of Consonants Articulation and the Talk Transmission Index. This Final Degree Project ends describing the budget and rent of the sound equipment and the final conclusions.

Genetic instability of cancer cells is proportional to their degree of aneuploidy

Genetic and phenotypic instability are hallmarks of cancer cells, but their cause is not clear. The leading hypothesis suggests that a poorly defined gene mutation generates genetic instability and that some of many subsequent mutations then cause cancer. Here we investigate the hypothesis that genetic instability of cancer cells is caused by aneuploidy, an abnormal balance of chromosomes. Because symmetrical segregation of chromosomes depends on exactly two copies of mitosis genes, aneuploidy involving chromosomes with mitosis genes will destabilize the karyotype. The hypothesis predicts that the degree of genetic instability should be proportional to the degree of aneuploidy. Thus it should be difficult, if not impossible, to maintain the particular karyotype of a highly aneuploid cancer cell on clonal propagation. This prediction was confirmed with clonal cultures of chemically transformed, aneuploid Chinese hamster embryo cells. It was found that the higher the ploidy factor of a clone, the more unstable was its karyotype. The ploidy factor is the quotient of the modal chromosome number divided by the normal number of the species. Transformed Chinese hamster embryo cells with a ploidy factor of 1.7 were estimated to change their karyotype at a rate of about 3% per generation, compared with 1.8% for cells with a ploidy factor of 0.95. Because the background noise of karyotyping is relatively high, the cells with low ploidy factor may be more stable than our method suggests. The karyotype instability of human colon cancer cell lines, recently analyzed by Lengnauer et al. [Lengnauer, C., Kinzler, K. W. & Vogelstein, B. (1997) Nature (London) 386, 623–627], also corresponds exactly to their degree of aneuploidy. We conclude that aneuploidy is sufficient to explain genetic instability and the resulting karyotypic and phenotypic heterogeneity of cancer cells, independent of gene mutation. Because aneuploidy has also been proposed to cause cancer, our hypothesis offers a common, unique mechanism of altering and simultaneously destabilizing normal cellular phenotypes.

Children's auditory perception and cognitive processing skills in adverse listening situations

Thesis (Ph.D.)--University of Washington, 2016-06

An adaptive code position modulation scheme for wireless sensor networks

In this letter, an energy-efficient adaptive code position modulation scheme is proposed for wireless sensor networks to provide the relatively stable bit error ratio (BER) performance expected by the upper layers. The system is designed with focus on the adaptive control of transmission power, which is adjusted based on the measured power density of background noise. Interfaces among the modulation module, packet scheduling module and upper layer are provided for flexible adjustments to adapt to the background noise and deliver expected application quality. Simulations with Signal Processing Worksystem (SPW) validate the effectiveness of the scheme. © 2005 IEEE.

Investigating microphone efficacy for facilitation of mobile speech-based data entry

Despite being nominated as a key potential interaction technique for supporting today's mobile technology user, the widespread commercialisation of speech-based input is currently being impeded by unacceptable recognition error rates. Developing effective speech-based solutions for use in mobile contexts, given the varying extent of background noise, is challenging. The research presented in this paper is part of an ongoing investigation into how best to incorporate speechbased input within mobile data collection applications. Specifically, this paper reports on a comparison of three different commercially available microphones in terms of their efficacy to facilitate mobile, speech-based data entry. We describe, in detail, our novel evaluation design as well as the results we obtained.

Development of a passive MEG stimulus for measurement of the binaural masking level difference

The ability to hear a target signal over background noise is an important aspect of efficient hearing in everyday situations. This mechanism depends on binaural hearing whenever there are differences in the inter-aural timing of inputs from the noise and the signal. Impairments in binaural hearing may underlie some auditory processing disorders, for example temporal-lobe epilepsies. The binaural masking level difference (BMLD) measures the advantage in detecting a tone whose inter-aural phase differs from that of the masking noise. BMLD’s are typically estimated psychophysically, but this is challenging in children or those with cognitive impairments. The aim of this doctorate is to design a passive measure of BMLD using magnetoencephalography (MEG) and test this in adults, children and patients with different types of epilepsy. The stimulus consists of Gaussian background noise with 500-Hz tones presented binaurally either in-phase or 180° out-of-phase between the ears. Source modelling provides the N1m amplitude for the in-phase and out-of-phase tones, representing the extent of signal perception over background noise. The passive BMLD stimulus is successfully used as a measure of binaural hearing capabilities in participants who would otherwise be unable to undertake a psychophysical task.

An algorithm for FHR estimation from foetal phonocardiographic signals

The long-term foetal surveillance is often to be recommended. Hence, the fully non-invasive acoustic recording, through maternal abdomen, represents a valuable alternative to the ultrasonic cardiotocography. Unfortunately, the recorded heart sound signal is heavily loaded by noise, thus the determination of the foetal heart rate raises serious signal processing issues. In this paper, we present a new algorithm for foetal heart rate estimation from foetal phonocardiographic recordings. A filtering is employed as a first step of the algorithm to reduce the background noise. A block for first heart sounds enhancing is then used to further reduce other components of foetal heart sound signals. A complex logic block, guided by a number of rules concerning foetal heart beat regularity, is proposed as a successive block, for the detection of most probable first heart sounds from several candidates. A final block is used for exact first heart sound timing and in turn foetal heart rate estimation. Filtering and enhancing blocks are actually implemented by means of different techniques, so that different processing paths are proposed. Furthermore, a reliability index is introduced to quantify the consistency of the estimated foetal heart rate and, based on statistic parameters; [,] a software quality index is designed to indicate the most reliable analysis procedure (that is, combining the best processing path and the most accurate time mark of the first heart sound, provides the lowest estimation errors). The algorithm performances have been tested on phonocardiographic signals recorded in a local gynaecology private practice from a sample group of about 50 pregnant women. Phonocardiographic signals have been recorded simultaneously to ultrasonic cardiotocographic signals in order to compare the two foetal heart rate series (the one estimated by our algorithm and the other provided by cardiotocographic device). Our results show that the proposed algorithm, in particular some analysis procedures, provides reliable foetal heart rate signals, very close to the reference cardiotocographic recordings. © 2010 Elsevier Ltd. All rights reserved.

A plasticidade acústica de uma população de Boto - Cinza, Sotalia Guianensis (Van Banédén, 1864) (Cetacea, Delphinidae), na região Nordeste do Brasil

The environmental characteristics can modify the acoustics of a species due to habitat, time of day and year. Therefore, this study investigated the relationships between seasons, tide, daily cycle of tides, times of day and different habitat and noise emission of S. guianensis. Sound recordings occurred in the Curral’s Cove and Lagoon Complex of Guaraíras (CLG) in the municipality of Tibau do Sul/RN. Whistles are emitted with lower frequency during rainy season and spring tide while clicks are higher; whistles, clicks and calls have higher frequency during ebb tide. These modifications can be related with turbidity and prey availability. The whistles and clicks occurrence are higher at night probably because luminosity is lower. Furthermore, the whistles and clicks frequency reduction overnight allows the sound to travel longer distance and helps the view which is limited; but the minimum frequency increase was needed to catch the prey. The low occurrence of calls could be related to the small group size. The acoustic changes at night may be partly influenced by light levels as prey availability that is larger in this period. Whistle frequencies and click initial frequency are higher in CLG than Curral’s cove that permitted good precision. However, click central frequency is lower and may be connected to tracking the area. Several factors may be associated with such modifications as background noise, bottom and others. This study supports the hypothesis that S. guianensis presents an acoustic plasticity according to the local conditions where the species is embedded and adapts to the environmental changes.

Secrecy Capacity Analysis Over κ–μ Fading Channels: Theory and Applications

In this paper, we consider the transmission of confidential information over a κ-μ fading channel in the presence of an eavesdropper who also experiences κ-μ fading. In particular, we obtain novel analytical solutions for the probability of strictly positive secrecy capacity (SPSC) and a lower bound of secure outage probability (SOPL) for independent and non-identically distributed channel coefficients without parameter constraints. We also provide a closed-form expression for the probability of SPSC when the μ parameter is assumed to take positive integer values. Monte-Carlo simulations are performed to verify the derived results. The versatility of the κ-μ fading model means that the results presented in this paper can be used to determine the probability of SPSC and SOPL for a large number of other fading scenarios, such as Rayleigh, Rice (Nakagamin), Nakagami-m, One-Sided Gaussian, and mixtures of these common fading models. In addition, due to the duality of the analysis of secrecy capacity and co-channel interference (CCI), the results presented here will have immediate applicability in the analysis of outage probability in wireless systems affected by CCI and background noise (BN). To demonstrate the efficacy of the novel formulations proposed here, we use the derived equations to provide a useful insight into the probability of SPSC and SOPL for a range of emerging wireless applications, such as cellular device-to-device, peer-to-peer, vehicle-to-vehicle, and body centric communications using data obtained from real channel measurements.

Using the interaural time difference and cross-correlation to localise short-term complex noises

The mammalian binaural cue of interaural time difference (ITD) and cross-correlation have long been used to determine the point of origin of a sound source. The ITD can be defined as the different points in time at which a sound from a single location arrives at each individual ear [1]. From this time difference, the brain can calculate the angle of the sound source in relation to the head [2]. Cross-correlation compares the similarity of each channel of a binaural waveform producing the time lag or offset required for both channels to be in phase with one another. This offset corresponds to the maximum value produced by the cross-correlation function and can be used to determine the ITD and thus the azimuthal angle θ of the original sound source. However, in indoor environments, cross-correlation has been known to have problems with both sound reflections and reverberations. Additionally, cross-correlation has difficulties with localising short-term complex noises when they occur during a longer duration waveform, i.e. in the presence of background noise. The crosscorrelation algorithm processes the entire waveform and the short-term complex noise can be ignored. This paper presents a technique using thresholding which enables higher-localisation abilities for short-term complex sounds in the midst of background noise. To determine the success of this thresholding technique, twenty-five sounds were recorded in a dynamic and echoic environment. The twenty-five sounds consist of hand-claps, finger-clicks and speech. The proposed technique was compared to the regular cross-correlation function for the same waveforms, and an average of the azimuthal angles determined for each individual sample. The sound localisation ability for all twenty-five sound samples is as follows: average of the sampled angles using cross-correlation: 44%; cross-correlation technique with thresholding: 84%. From these results, it is clear that this proposed technique is very successful for the localisation of short-term complex sounds in the midst of background noise and in a dynamic and echoic indoor environment.