Abstract: The present disclosure discloses an acoustic output apparatus including at least one acoustic driver, a controller, and a supporting structure. The at least one acoustic driver may be configured to output sounds through at least two sound guiding holes. The at least two sound guiding holes may include a first sound guiding hole and a second sound guiding hole. The controller may be configured to control a phase and an amplitude of the sounds generated by the at least one acoustic driver using a control signal such that the sounds output by the at least one acoustic driver through the first and second sound guiding holes have opposite phases. The supporting structure may be provided with a baffle and configured to support the at least one acoustic driver such that the first and second sound guiding holes are located on both sides of the baffle.

Abstract: A system for generating surround sound is disclosed. The system may be used for replicating a sonic space that can be reproduced around an end user listener. Applications may include general rebroadcasting of an event or use in a virtual reality setting. The sound captured may be live sound or a recorded sound. The system includes microphones positioned in multiple positions on or proximate an audio source subject. Speakers are positioned relative to each other in a cuboctahedral arrangement around an acoustic point of reference. An audio processing unit connected wirelessly to the microphones processes individual signals from the microphones and transmits the individual signals to the plurality of speakers.

Abstract: A headphone includes two earphone bodies, a head mount bracket, two elastic portions and two ear cushions. The head mount bracket is connected to the two earphone bodies. The two elastic portions are respectively connected to the two earphone bodies, and respectively have a concave surface. The two ear cushions are respectively disposed on the concave surfaces of the two elastic portions and are used to contact a user's ears.

Abstract: A system and method for measuring phase variations in signals are disclosed. The system and method may be integrated inside a circuit pack in the form of a built-in-self-test (BIST) unit. The BIST provides predetermined periodic attenuation to an input signal and determines phase variation in output signal due to applied attenuations by measuring sideband power of the output signal.

Abstract: An electronic device may be coupled to an accessory such as a pair of earphones. The earphones may have ear presence sensor structures that determine whether or not the ears of a user are present in the vicinity of the earphones. The earphones may contain first and second speakers. When both the first and second speakers are located in the ears of the user, the electronic device may perform functions such as playing audio content. When one of the speakers has been removed from the ears of the user while the other of the speakers remains in the ears of the user, the electronic device can take actions such as pausing the playback of audio content, switching from stereo to monophonic playback, or stopping the playback of content. Suitable actions such as increasing audio drive strength may be taken when both speakers have been removed from the ears.

Abstract: Automatic measurements are made of audio presence and level in an audio signal by direct processing of an MPEG data stream representing the audio signal, without reconstructing the audio signal. Sub-band data is extracted from the data stream, and the extracted sub-band data is dequantized and denormalized. An audio level for the dequantized and denormalized sub-band data is measured without reconstructing the audio signal. Channel characteristics are used in measuring the audio level of the sub-band data, wherein the channel characteristics are used to weight the measured levels. The measured levels are compared against at least one threshold to determine whether an alarm should be triggered.

Abstract: A conventional billboard for displaying a visual message is combined with a communication system for enabling a message related to the message displayed by the billboard to be transmitted from the billboard to passengers of automotive vehicles driving by said billboard. The communication system includes a transmitter located at the billboard and connected to an external telephone line. A telephone unit, disposed at a remote business office, supplies the related message over the telephone line to the transmitter. Receivers, located in individual automotive vehicles, receive the transmitted message. The transmitter includes a recorder for recording the related message received from the telephone unit and a control unit for controlling recording and playback of that message.

Abstract: An improved theater surround sound system incorporates a screen top speaker and an overhead speaker driven by corresponding upper surround channels to more accurately reproduce sounds produced from above the listener. These top surround channels are encoded along with the left and right surround channels. A pilot signal is used to direct the sound from the side surround channels to the upper surround channels when needed.

Abstract: A device and method for composite signal decoding is provided in which an analog-to-digital converter (15) digitizes an incoming FM composite signal. The digitized signal is filtered by an interpolator (13) which uses filter coefficients developed as a function of a sampled pilot signal's phase without synchronizing the decoder sample rate to the pilot signal to reconstruct the composite signal at points Where the pilot signal phase is a multiple of 45.degree..