Abstract: Example methods, apparatus, systems and articles of manufacture to implement down-mixing compensation for audio watermarking are disclosed. Example watermark embedding methods disclosed herein include determining a first attenuation factor associated with a first audio channel of a multi-channel audio signal based on first down-mixed audio samples obtained from down-mixing the first audio channel and a second audio channel of the multi-channel audio signal, determining a second attenuation factor associated with a third audio channel of the multi-channel audio signal based on second down-mixed audio samples obtained from down-mixing the second audio channel and the third audio channel of the multi-channel audio signal, selecting one of the first attenuation factor or the second attenuation factor to be a third attenuation factor associated with the second audio channel of the multi-channel audio signal, and embedding a watermark in the second audio channel based on the third attenuation factor.

Abstract: An exemplary apparatus minimizes an aircraft propeller noise having an associated frequency and a corresponding wavelength. A resonant tone produced on the propeller blade elicits a sound with substantially the same frequency as the associated frequency of the offending source. The resonant tone is powered by an inflow of air in or across an aperture of a resonant structure during the rotation of the blade and the aperture has an opening from which the sound is emitted. The resonant structure is dimensioned to generate a sound with substantially the same frequency as the offending source. The aperture is located on the blade with the opening a distance from a target origin of the noise that is substantially one half of the wavelength of the noise so that the sound arrives at the target origin of the noise substantially 180 degrees out of phase with the noise.

Abstract: Directional sound location is used to determine security events of a security system. A sound sensor reports a vector direction to a sound source of an acoustic signal. If the vector direction is historically observed at similar times, then perhaps the sound source is not considered a security event. However, if the vector direction is unknown or unfamiliar, the security system may infer the security event and notify emergency services.

Abstract: A method for forming a complete ring network of a plurality of Bluetooth® speakers, the method including populating a configurable speaker register of each of the plurality of Bluetooth® speakers with an address of an upstream Bluetooth® speaker that is in the plurality of Bluetooth® speakers, populating the configurable speaker register of each of the plurality of Bluetooth® speakers with an address of a downstream Bluetooth® speaker that is in the plurality of Bluetooth® speakers, and coupling an audio source to one Bluetooth® speaker of the plurality of Bluetooth® speakers.

Abstract: A user terminal comprising; a loudspeaker; a microphone; and an audio signal processing module comprising: a reference signal generator configured, prior to establishment of a communication event over a network with at least one further terminal, to generate and output an audio reference signal to the loudspeaker for playout; an echo removal module configured to perform echo removal on audio signals received via the microphone during the communication event; and a detector configured, prior to establishment of the communication event, to: determine characteristics of the reference signal; receive an audio signal output from the microphone which includes echo resulting from the outputted reference signal; determine characteristics of the received audio signal; compare the determined characteristics of the reference signal with determined characteristics of the received audio signal to detect a nonlinear echo path of the echo, and configure a component of the audio signal processing module based on this detecti

Abstract: A circuit may include an audio amplifier (314) configured to amplify an input signal (SAUDIO) to generate an output signal (SOUT+, SOUT?) suitable for driving a loud speaker (316). A first circuit (318) may be configured to generate a first analog signal (SI) based on a current level drawn by the loud speaker (316), and a second circuit (320) may be configured to generate a second analog signal (SV) based on a voltage supplied across the loud speaker (316). A third circuit (322, 312) may be configured to generate a third analog signal (RESIDUE) based on the difference between the first and second analog signals, and modify the input signal (SAUDIO) based on the third analog signal.

Abstract: Systems and methods to perform speaker clustering determine which audio segments appear to include sound generated by the same speaker. Speaker clustering is based on creating a graph in which a node represents an audio segment and an edge between two nodes represents a relationship and/or correspondence that reflects a probability, likelihood, or other indication that the two nodes represent audio segments of the same speaker. This graph is analyzed to detect individual communities of nodes that associate to an individual speaker.

Abstract: A method for audio signal processing and system thereof, the method includes the steps of: obtaining first audio signal information, obtaining second audio signal information, determining an audio parameter based on the first audio signal information and the second audio signal information, modulating the first audio signal information and the second audio signal information based on the audio parameter to generate a first outputting audio signal and a second outputting audio signal.

Abstract: An acoustic system includes a supply device, which is connected to a network and configured to supply an acoustic signal to the network, and at least one output device configured to output a sound based on the acoustic signal supplied from the supply device via the network. Also, the acoustic system includes a control unit, which is provided to the at least one output device on a one-to-one basis, and configured to control necessity/non-necessity of outputting the acoustic signal to an associated one of the at least one output device, based on frequency characteristics of the acoustic signal.

Abstract: A mobile device including an audio processor processing audio data and generating an audio signal, an outputter outputting the audio signal, a communicator that may be connected to an AP (Access Point) network, and a controller, in response to a predetermined event occurring with the audio signal being output, transmitting the audio signal to an external speaker included in the AP network through the communicator and controlling the external speaker to output the audio signal.

Abstract: A method includes receiving sound by a first audio unit installed in an electrical outlet, routing audio data corresponding to the received sound from the first audio unit to a second audio unit installed in a second electrical outlet, and sending the audio data to a mobile device using a wireless link between the mobile device and the second audio unit. Routing the audio data may include receiving the audio data from the first audio unit by a third audio unit and routing the audio data to the second audio unit by the third audio unit serving as a router. The data may be routed using table driven routing, on-demand routing or some other appropriate routing protocol. The method may also include performing voice recognition on the audio data and detecting a command word and routing command word data to the second audio unit.

Abstract: Methods and systems for controlling audio communications between occupants of a vehicle are provided. In accordance with one embodiment, a system includes an interface and a processor. The interface is configured to at least facilitate receiving a request for sound transmission from a first occupant inside a vehicle to a second occupant inside the vehicle. The processor is coupled to the interface, and is configured to at least facilitate identifying respective locations of the first occupant and the second occupant, and performing the sound transmission with an adjustment for a phase difference based at least in part on the respective locations of the first occupant and the second occupant.

Abstract: An audio source location, tracking and isolation system, particularly suited for use with person-mounted microphone arrays. The system increases capabilities by reducing resources required for certain functions so those resources can be utilized for result enhancing processes. A wide area scan may be utilized to identify the general vicinity of an audio source and a narrow scan to locate pinpoint positions may be initiated in the general vicinity identified by the wide area scan. Subsequent locations may be anticipated by compensating for motion of the sensor array and anticipated changes in source location by trajectory. Identification may use two or more sets of characterizations and rules. The characterizations may use computationally less intense analyzes to characterize audio and only perform computationally higher intensity analysis if needed. Rule sets may be used to eliminate the need to track audio sources that emit audio to be eliminated from an audio output.

Abstract: An electronic hearing protector includes an ear cup assembly comprising a front exterior microphone that provides a front microphone signal and a rear exterior microphone that provides a rear microphone signal. A processor receives and digitizes the front microphone signal and the rear microphone signal, and provides a front channel signal and a rear channel signal indicative thereof respectively. A filter receives the rear channel signal and has a cut-off frequency value that provides a high-frequency roll-off and a notch at a notch filter frequency value that is less than the cut-off frequency value, where the filter provides a filtered signal. A first signal indicative of the front channel signal and a second signal indicative of the filtered signal are summed, and a signal indicative of the summed signal is provided to a speaker within the ear cup that provides an audio signal within the first ear cup indicative of the summed signal.

Abstract: Filtering containing a delay by a specific time is performed on one of the pair of input signals are input from microphones L, R. After the filtering, a pair of input signals InL and InR are alternately interchanged for each sampling by an interchanging circuit 2 to generate a pair of interchanged signals InA and InB. The one interchanged signal InB is multiplied by a coefficient m by an coefficient updating circuit 3 to generate an error signal of the interchanged signals InA and InB. The recurrence formula of the coefficient m containing the error signal is calculated to update the coefficient m for each sampling. The pair of input signals InL and InR are multiplied by the sequentially updated coefficient m and are output.

Abstract: An audio signature is generated by a user device by generating an audio signal indicative of the user device, outputting the audio signal indicative of the user device through a speaker of the user device, using a microphone of the user device to sense audio, generating an audio signature of the audio sensed by the microphone in the user device, and transmitting the audio signature from the user device to a communication channel. The audio signal may be used by another user device which generates its own audio signature, and which can be compared to the audio signature of the user device that originally generated the audio signal to determine if the user devices are co-located.

Abstract: A speaker impedance may be determined by monitoring a voltage and/or current of the speaker. The calculated impedance may be used to determine whether the mobile device containing the speaker is on- or off-ear. The impedance determination may be assisted by applying a test tone low level signal to the speaker. The test tone may be inaudible to the user, but used to determine an impedance of the speaker at the frequency of the test tone. The impedance at that test tone may be used to determine whether a resonance frequency of the speaker is at a frequency corresponding to an on- or off-ear condition. The measured speaker impedance may be provided as feedback to an adaptive noise cancellation (ANC) algorithm to adjust the output at the speaker. For example, when the mobile device is removed from the user's ear, the ANC algorithm may be disabled.

Abstract: A method for determining an estimation of a secondary path transfer characteristic in an ANC system is described herein. In accordance with one example of the invention, the method includes the positioning of a microphone array in a listening room symmetrically with respect to a desired listening position and reproducing at least one test signal using a loudspeaker arranged within the listening room to generate an acoustic signal. The acoustic signal is measured with the microphones of the microphone array to obtain a microphone signal from each microphone of the microphone array, and a numerical representation of the secondary path transfer characteristic is calculated for each microphone signal based on the test signal and the respective microphone signal. The method further includes averaging the calculated numerical representations of the secondary path transfer characteristic to obtain the estimation of the secondary path transfer characteristic to be used in the ANC system.

Abstract: A loudspeaker system includes a housing having an upper housing unit, a lower housing unit, and a cylindrical passageway connecting the upper housing unit and the lowering housing unit such that the upper housing unit and the lower housing unit are in fluid communication. A driver mounting plate is secured within the lower housing unit and divides the housing into an upper compartment and a lower compartment. At least one of the side walls of the lower housing unit includes a side wall aperture linking the lower compartment to an external environment surrounding the housing. A driver is mounted to the driver mounting plate, the driver being positioned to fire into the lower compartment of the housing.

Abstract: A MEMS device includes a backplate electrode and a membrane disposed spaced apart from the backplate electrode. The membrane includes a displaceable portion and a fixed portion. The backplate electrode and the membrane are arranged such that an overlapping area of the fixed portion of the membrane with the backplate electrode is less than maximum overlapping.