Leaks in the enclosed acoustical system of the stethoscope reduce its efficiency and can greatly impair the physician's ability to detect the faint murmurs of early valvular heart disease. The results of this study demonstrate a high degree of variability in size and configuration of the external auditory meatus among different individuals. It appears probable that both excessive leaks and also...

This paper describes an interdisciplinary project on room acoustics. The main goals of this project is to identify and analyse the relevant acoustical parameters for small rooms used for music production – concert halls, studios, lecture rooms, movie theatres, etc. – and, using modern methodologies for software development, build computational tools to evaluate and manipulate these parameters. ...

Acoustical mismatch between training and testing phases induce degradation of performance in automatic speaker recognition systems [1,2]. Providing robustness to speaker recognizers has to be, therefore, a priority matter. Robustness in the acoustical stage can be accomplished through speech enhancement techniques as a prior stage to the recognizer. These techniques are oriented to the reductio...

In this study acoustical as well as lexical/syntactic correlates of prominence are analyzed and discussed. Prominence is defined at the word level and is based on listener judgments. Spoken sentences from many different speakers, taken from the Dutch Polyphone corpus of telephone speech, are analyzed. A selection of useful acoustical input features is chosen for classification of word prominenc...

The time it takes a sound to travel from source to ear differs between the ears and creates an interaural delay. It varies systematically with spatial direction and is generally modeled as a pure time delay, independent of frequency. In acoustical recordings, we found that interaural delay varies with frequency at a fine scale. In physiological recordings of midbrain neurons sensitive to intera...

In previous studies, the localisation accuracy and the spatial impression of 3-2 stereo microphone arrays were discussed. These showed that 3-2 stereo cannot produce stable images to the side and to the rear of the listener. An octagon loudspeaker array was therefore proposed. Microphone array design for this loudspeaker configuration was studied in terms of localisation accuracy, locatedness a...

There are many techniques available to study physical properties to interpret the molecular interaction in liquids, liquid mixtures and solutions. The study of ultrasonic waves through solution is found to be quite interesting. The study of ultrasonic waves through solution is used for knowing the nature and strength of intermolecular forces and their interaction in liquids, liquid mixtures and...

The acoustical impedance of a component is one of its most important characteristics. It is needed when acoustical simulations using lumped elements or electrical analog circuits are carried out. The calibration procedure for the two microphone transfer function method described in ISO 10534-2 is not sufficiently accurate in most cases. In this paper, a new calibration method for the two microp...

This paper illustrates a new system for recovering clean speech signals from noisy acoustical environments using one microphone. At the beginning of this paper, we propose an assumption that the background noise is comprised of reverberant noise and direct-path noise. And a novel late reverberant spectral variance (LRSV) estimator is generated referring to this assumption, which can be used in ...

Recent research efforts on nonlinear propagation from high performance jet aircraft have revealed an interesting challenge to predicting community response. This challenge focuses on receiver perception of these unique acoustical signals, which contain acoustical shocks that appear to increase their relative loudness and/or noisiness. This current finding suggests a need for an improved descrip...