Change in rapid eye movement (REM) sleep in response to exposure to all-night noise and transient noise.

Abstract: Hearing in laboratory animals is a topic that traditionally has been the domain of the auditory researcher. However, hearing loss and exposure to various environmental sounds can lead to changes in multiple organ systems, making what laboratory animals hear of consequence for researchers beyond those solely interested in hearing. For example, several inbred mouse strains commonly used in biomedical research (e.g., C57BL/6, DBA/2, and BALB/c) experience a genetically determined, progressive hearing loss that can lead to secondary changes in systems ranging from brain neurochemistry to social behavior. Both researchers and laboratory animal facility personnel should be aware of both strain and species differences in hearing in order to minimize potentially confounding variables in their research and to aid in the interpretation of data. Independent of genetic differences, acoustic noise levels in laboratory animal facilities can have considerable effects on the inhabitants. A large body of literature describes the nonauditory impact of noise on the biology and behavior of various strains and species of laboratory animals. The broad systemic effects of noise exposure include changes in endocrine and cardiovascular function, sleep-wake cycle disturbances, seizure susceptibility, and an array of behavioral changes. These changes are determined partly by species and strain; partly by noise intensity level, duration, predictability, and other characteristics of the sound; and partly by animal history and exposure context. This article reviews some of the basic strain and species differences in hearing and outlines how the acoustic environment affects different mammals.

Abstract: Los trastornos del sueno constituyen uno de los problemas de salud mas relevantes en las sociedades occidentales. La importancia de una buena calidad de sueno no solamente es fundamental como factor determinante de la salud, sino como elemento propiciador de una buena calidad de vida. La calidad del sueno no se refiere unicamente al hecho de dormir bien durante la noche, sino que tambien incluye un buen funcionamiento diurno (un adecuado nivel de atencion para realizar diferentes tareas). Ello hace que sea fundamental estudiar la incidencia de estos trastornos en distintos tipos de poblaciones, asi como los factores que los determinan. Para alcanzar este objetivo, y ante las dificultades que implica la evaluacion polisomnografica en la deteccion de la calidad de sueno, en la mayoria de los casos se opta por el uso de instrumentos de autoinforme, entre los que destaca el Indice de Calidad del Sueno de Pittsburg. Desde la evaluacion conductual consideramos que el sueno esta determinado por cuatro diferentes dimensiones: tiempo circadiano, esto es, la hora del dia en que se localiza, factores intrinsecos del organismo (edad, sueno, patrones de sueno), conductas facilitadoras e inhibidoras realizadas por el sujeto y el ambiente en que duerme. La higiene del sueno incide sobre estas dos ultimas dimensiones, y en nuestro estudio nos centraremos en las conductas inhibidoras (consumo de sustancias psicoactivas). En el estudio se analiza la calidad subjetiva del sueno en una muestra de 716 estudiantes universitarios (584 mujeres y 132 varones) por medio del Indice de Calidad del Sueno de Pittsburg, y se evaluan los efectos del consumo de alcohol, cafeina y tabaco sobre la calidad del sueno. El Indice de Calidad del Sueno de Pittsburg proporciona una puntuacion global de la calidad del sueno y puntuaciones parciales en siete componentes distintos: calidad subjetiva del sueno, latencia del sueno, duracion del sueno, eficiencia habitual del sueno, alteraciones del sueno, uso de medicacion hipnotica y disfuncion diurna. Los resultados encontrados muestran que aproximadamente 30% de la muestra presenta una mala calidad del sueno, una excesiva latencia y una pobre eficiencia del sueno; no se encontraron diferencias entre hombres y mujeres en ningun componente, a excepcion del consumo de hipnoticos, donde las mujeres presentan una mayor puntuacion. Ello parece indicar que las dificultades para iniciar el sueno constituyen una caracteristica de la mala calidad del sueno en los sujetos mas jovenes, mientras que en las personas mayores lo caracteristico son los despertares nocturnos y el despertar precoz. La falta de diferencias en la calidad del sueno entre hombres y mujeres se puede deber a la edad de la muestra (20.92 anos), pues en las mujeres la menor calidad del sueno se hace mas evidente a medida que avanza la edad. Si tenemos en cuenta la puntuacion total del Indice de Calidad del Sueno de Pittsburg, encontramos que 60.33% de la muestra supera la puntuacion de cinco, por lo que estos sujetos pueden ser definidos como malos dormidores. Por otro lado, esta claramente demostrado que el uso excesivo de alcohol, cafeina y nicotina provoca alteraciones del sueno: aumento de la latencia, despertares nocturnos, reduccion del sueno de ondas lentas, reduccion del tiempo total de sueno y pobre calidad autoinformada del sueno. Sin embargo, el efecto que tiene el consumo social (consumo no excesivo) de estas sustancias sobre el sueno es menos conocido. En este estudio hemos definido como consumidores sociales a los sujetos que ingieren entre dos y cuatro copas de alcohol, dos y cuatro tazas de cafe y fuman entre 20 y 30 cigarrillos diariamente. Encontramos que el consumo diario habitual no excesivo de alcohol, cafeina y tabaco, provoca una mala calidad del sueno, una mayor latencia , un mayor numero de perturbaciones y una mayor disfuncion diurna. Esto pone de manifiesto la necesidad de controlar el consumo de estas sustancias para mantener una correcta calidad del sueno.

Abstract: The effect of reducing reverberation time was studied in 12 subjects during sleep EEG-arousals following specific sound stimuli were significantly reduced (p<0007) when reverberation time was reduced with sound-absorbing ceiling-tiles On average reverberation was reduced 0124 seconds at similar sound levels It is proposed that increased sound absorption, ie reduced reverberation time, by contributing to a better acoustic environment may reduce sound-induced sleep fragmentation

Abstract: The aim of this study was to explore and compare the effect of noise from railway and road traffic on sleep in subjects habitually exposed to nocturnal noise. Forty young and middle aged healthy subjects were studied with polysomnography (PSG) during two consecutive nights in their own bedroom. Noise measurements and recordings were conducted concurrently outside of the bedroom facade as well as inside the bedroom of each participant. Different noise exposure parameters were calculated (L(p,A,eq,night), L(p,A,Fmax,night), and L(AF5,night)) and analyzed in relation to whole-night sleep parameters. The group exposed to railway noise had significantly less Rapid eye movement, (REM) sleep than the group exposed to road traffic noise. A significant association was found between the maximum level (L(p,A,Fmax,night)) of railway noise and time spent in REM sleep. REM sleep was significantly shorter in the group exposed to at least a single railway noise event above 50 dB inside the bedroom. These results, obtained in an ecological valid setting, support previous laboratory findings that railway noise has a stronger impact than road traffic noise on physiological parameters during sleep, and that the maximum noise level is an important predictor of noise effects on sleep assessed by PSG, at least for railway noise.

Abstract: An appropriate sleep environment is critical to achieve adequate quality and quantity of sleep. General sleep hygiene recommendations suggest that individuals should maintain a cool, dark, quiet sleep environment. Our goal was to conduct a review of the evidence surrounding the optimal characteristics for the sleep environment in the categories of noise, temperature, lighting, and air quality in order to provide specific recommendations for each of these components. We found that all forms of noise in the sleep environment should be reduced to below 35 dB. The optimal ambient temperature varies based on humidity and the bedding microclimate, ranging between 17 and 28 °C at 40–60% relative humidity. Complete darkness is optimal for sleep and blue light should be avoided during the sleep opportunity. Sea level air quality, with ventilation is optimal for sleep and supplemental oxygen is a useful countermeasure for improving sleep quality at altitude. Architectural design that incorporates these elements into bedroom design may improve sleep quality among inhabitants of such environments.

Abstract: Despite the prevalence of sleep complaints among psychiatric patients, few questionnaires have been specifically designed to measure sleep quality in clinical populations. The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire which assesses sleep quality and disturbances over a 1-month time interval. Nineteen individual items generate seven "component" scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of scores for these seven components yields one global score. Clinical and clinimetric properties of the PSQI were assessed over an 18-month period with "good" sleepers (healthy subjects, n = 52) and "poor" sleepers (depressed patients, n = 54; sleep-disorder patients, n = 62). Acceptable measures of internal homogeneity, consistency (test-retest reliability), and validity were obtained. A global PSQI score greater than 5 yielded a diagnostic sensitivity of 89.6% and specificity of 86.5% (kappa = 0.75, p less than 0.001) in distinguishing good and poor sleepers. The clinimetric and clinical properties of the PSQI suggest its utility both in psychiatric clinical practice and research activities.

Abstract: A model is proposed for tinnitus and sensorineural hearing loss involving cochlear pathology. As tinnitus is defined as a cortical perception of sound in the absence of an appropriate external stimulus it must result from a generator in the auditory system which undergoes extensive auditory processing before it is perceived. The concept of spatial nonlinearity in the cochlea is presented as a cause of tinnitus generation controlled by the efferents. Various clinical presentations of tinnitus and the way in which they respond to changes in the environment are discussed with respect to this control mechanism. The concept of auditory retraining as part of the habituation process, and interaction with the prefrontal cortex and limbic system is presented as a central model which emphasizes the importance of the emotional significance and meaning of tinnitus.