Time reversal operator (TRO) decompositions are performed in a model of an ocean wave guide containing a target and having different kinds of bottom. The objective is to study the effects of bottom reverberation and absorption by means of ultrasonic experiments. It is shown experimentally that the echo from a target can be separated from the bottom reverberation. Reverberation eigenvectors are ...

Spring reverberation is a sonically unique form of artificial reverberation, desirable as an effect distinct from that of more conventional reverberation. Recent work has introduced a parametric model of spring reverberation based on long chains of allpass filters. Such chains can be computationally expensive. In this paper, we propose a number of modifications to these structures, via the appl...

Echo-to-reverberation enhancement previously has been demonstrated using time reversal focusing when knowledge of the channel response between a target and the source array elements is available. In the absence of this knowledge, direct focusing is not possible. However, active reverberation nulling still is feasible given observations of reverberation from conventional source array transmissio...

In this paper a study of the acoustical response of a new built church is shown. This study is based on the measurement of reverberation time, adopting the noise interrupted method, according to the International Standard. This method allows to evaluate the reverberation time by means of acoustical sound level acquisition and analysis. The reverberation time is one of the principal parameters t...

This paper describes a highly versatile, low-cost reverberation system comprising two main elements: a computer for building and editing the desired reverberation effect impulse response, and a commercial DSP-based board, to run the algorithm in real-time, allowing the evaluation of the results. The main parameters of the reverberation algorithm can be modified by means of a dedicated graphic i...

We describe a technique for robust recognition of reverberated speech using the ‘missing data’ paradigm. Modulation filtering is used to identify time-frequency regions of the speech signal which are relatively uncontaminated by reverberation and contain strong speech energy; only these ‘reliable’ acoustic features are made directly available to the recogniser. The proposed system is evaluated ...