30 results about "Parametric loudspeaker" patented technology

A method is disclosed for increasing a parametric output of a parametric loudspeaker system. The method can include the operation of providing multiple ultrasonic frequency emission zones that output signals in a frequency band. The phase relationships of the ultrasonic frequency emission zones can be correlated and controlled to increase phase coherence between each ultrasonic frequency emission zone to maximize parametric output. Correlating and controlling the phase relationships can include offsetting a frequency of a carrier signal applied to each emission zone from a resonant frequency of each emission zone in view of a rate of change of phase of each emission zone in a vicinity of each resonant frequency. Ultrasonic energy from the ultrasonic frequency emission zones can be generated, using the correlated phase relationship to increase the parametric output.

An acoustic sound system usable in electronic entertainment systems that generates highly directional sound. The directed acoustic sound system includes a parametric audio sound system having a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated signal, and a parametric loudspeaker for projecting the modulated and amplified signal through the air for subsequent regeneration of the audio signal along a pre-selected path. The acoustic sound system allows a user to select the parametric loudspeaker, a connectable non-directional loudspeaker, or both loudspeakers for producing audible sound. The acoustic sound system may be employed in the home, in the workplace, or in any other environment where audio leakage is undesirable.

A parametric loudspeaker system comprises a pre-compensator (305) for generating a pre-compensated envelope signal by applying a pre-compensation to the input audio signal where the pre-compensation compensates for distortion of in-air demodulation of the modulated ultrasound signal. A pre-modulator (307) generates a complex base band signal generating a phase signal from the pre-compensated envelope signal using a predetermined function for determining a phase signal from an amplitude signal such that the corresponding complex signal has either suppressed negative or positive frequencies. The complex base band signal is then generated to have an amplitude corresponding to the pre-compensated envelope signal and a phase corresponding to the phase signal. A modulator (309) quadrature modulates the complex base band signal on an ultrasonic quadrature carrier and an output circuit (311) drives the ultrasound transducer (301) from the modulated signal. The invention may allow effective yet low resource pre-compensation for a suppressed or single sideband modulated modulated ultrasound signal.

A sound reproducing device includes parametric speakers disposed to a display, a loudspeaker, drivers, a human-body sensor, and a controller. The loudspeaker has a wider directivity than the parametric speakers. The drivers change directions of the parametric speakers, respectively. The parametric speakers and the drivers constitute at least two parametric speaker units each composed of respective one of the parametric speakers and respective one of the drivers. The controller reproduces sound information based the number of persons in front of the display detected from an output from the human-body senor. The sound reproducing device reduces the possibility for a number of persons to hear the sound nosily, and allows drawing more attention to the content, e.g. an advertisement.