Abstract: A system for determining fluid velocity of a fluid flow to which the system is exposed, the system comprising: an acoustic structure including a radiating element and an acoustic volume acoustically coupled to the radiating element, a microphone located inside the acoustic volume, and a wire coupled to the radiating element such that, when the wire is subject to the fluid flow, vibrations of the wire are transmitted to the radiating element, and resulting vibrations of the radiating element radiate corresponding vibrations into the acoustic volume, wherein the microphone is sensitive to said vibrations radiated into the acoustic volume, and the output of the microphone in response to said vibrations is related to the fluid velocity of the fluid flow to which the wire is subject.

Abstract: An apparatus includes an enclosure capable of receiving a transducer for converting electrical signals into audible signals. The apparatus also includes one or more structures within the enclosure defining one or more channels, each channel having one end located within the enclosure and another end that is external to the enclosure. The apparatus also includes an acoustic resistive element located in the one of the one or more structures, the acoustic resistive element being capable of changing the acoustic characteristics of at least one of the one or more channels within the enclosure.

Abstract: An apparatus includes an enclosure capable of receiving an array of transducers for converting electrical signals into steered audible signals. The apparatus also includes one or more structures within the enclosure defining a port having one end located within the enclosure and another end that is external to the enclosure. The apparatus also includes an acoustic resistive element located in the one of the one or more structures, the acoustic resistive element being capable of reducing effects of the acoustic characteristics of the port for audible signals being produced by the array of transducers.

Abstract: An apparatus includes an enclosure capable of receiving an array of transducers for converting electrical signals into steered audible signals. The apparatus also includes one or more structures within the enclosure defining a port having one end located within the enclosure and another end that is external to the enclosure. The apparatus also includes an acoustic resistive element located in the one of the one or more structures, the acoustic resistive element being capable of reducing effects of the acoustic characteristics of the port for audible signals being produced by the array of transducers.

Abstract: An apparatus includes an enclosure capable of receiving a transducer for converting electrical signals into audible signals. The apparatus also includes one or more structures within the enclosure defining one or more channels, each channel having one end located within the enclosure and another end that is external to the enclosure. The apparatus also includes an acoustic resistive element located in the one of the one or more structures, the acoustic resistive element being capable of changing the acoustic characteristics of at least one of the one or more channels within the enclosure.