Loudspeaker

About: Loudspeaker is a research topic. Over the lifetime, 14114 publications have been published within this topic receiving 104660 citations. The topic is also known as: speaker & Refoam.

The simulation of moving sound sources

Abstract: A digital computer was used to generate four channels of information, which are recorded on a tape recorder. The computer program provides control over the apparent location and movement of a synthesized sound in an illusory acoustical space. The method controls the distribution and amplitude of direct and reverberant signals between the loudspeakers to provide the angular and distance information and introduces a Doppler shift to enhance velocity information.

Systems, methods, apparatus, and computer-readable media for generating obfuscated speech signal

Abstract: Arrangements are described that may be used to reduce the intelligibility of speech using masker signals which are obfuscated yet correlated versions of the speech. Other applications of pitch analysis and demodulation are also described. A system may be used to drive an array of loudspeakers to produce a sound field that includes a source component, whose energy is concentrated along a first direction relative to the array, and a masking component that is based on an estimated intensity of the source component in a second direction that is different from the first direction.

Maximum Likelihood Sound Source Localization and Beamforming for Directional Microphone Arrays in Distributed Meetings

Abstract: In distributed meeting applications, microphone arrays have been widely used to capture superior speech sound and perform speaker localization through sound source localization (SSL) and beamforming. This paper presents a unified maximum likelihood framework of these two techniques, and demonstrates how such a framework can be adapted to create efficient SSL and beamforming algorithms for reverberant rooms and unknown directional patterns of microphones. The proposed method is closely related to steered response power-based algorithms, which are known to work extremely well in real-world environments. We demonstrate the effectiveness of the proposed method on challenging synthetic and real-world datasets, including over six hours of recorded meetings.

Automatic audio system equalizing

Abstract: An automated process for equalizing an audio system and an apparatus for implementing the process. An audio system includes a microphone unit, for receiving the sound waves radiated from a plurality of speakers, acoustic measuring circuitry, for calculating frequency response measurements; a memory, for storing characteristic data of the loudspeaker units and further for storing the frequency response measurements; and equalization calculation circuitry, for calculating an equalization pattern responsive to the digital data and responsive to the characteristic data of the plurality of loudspeaker units. Also described is an automated equalizing system including a acoustic measuring circuitry including a microphone for measuring frequency response at a plurality of locations; a memory, for storing the frequency responses at the plurality of locations; and equalization calculation circuitry, for calculating, from the frequency responses, an optimized equalization pattern.

Theory and design of sound field reproduction in reverberant rooms.

Abstract: With the recent emergence of surround sound technology, renewed interest has been shown in the problem of sound field reproduction. However, in practical acoustical environments, the performance of sound reproduction techniques are significantly degraded by reverberation. In this paper, we develop a method of sound field reproduction for reverberant environments. The key to this method is an efficient parametrization of the acoustic transfer function over a region of space. Using this parametrization, a practical method has been provided for determining the transfer function between each loudspeaker and every point in the reproduction region. Through several simulation examples, the reverberant field designs have been shown to yield a reproduction accuracy as good as conventional free-field designs, and better than multipoint least squares designs when loudspeaker numbers are limited. The successful reproduction of sound over a wide frequency range has also been demonstrated. This approach reveals the appropriate choices for fundamental design parameters.