Abstract: A system and a method for a blind direction of arrival estimation is provided for a nonlinear 1-dimensional array of M receivers of J<M unknown signals transmitted through an unknown channel and subject to Gaussian noise. The method overcomes the conditions of that signals be disjoint in the time-frequency domain and/or statistically independent. A likelihood function evaluates a probability for the directions of arrivals. A weighting and regularization scheme selects relevant frequency components. A joint likelihood function of all frequencies is interpreted as a cost or objective function. The time domain is included into the estimation procedure by using a particle filter that operates on the constructed likelihood function and a simple transition kernel for the directions.

Abstract: An information processing apparatus that detects a current location of the information processing apparatus; obtains a direction of a destination from the detected current location as a target direction; detects a facial orientation of a user wearing a headphone unit connected to the information processing apparatus via a wired or wireless connection in relation to a reference orientation based on outputs of a geomagnetic sensor and an acceleration sensor connected to the headphone unit; obtains a relative target angle based on a difference between the target direction and the user's facial orientation; and generates sound to be output by the headphone unit based on the obtained relative target angle.

Abstract: The transmission of a detection wave and the reception of a reflected wave are periodically repeated every transmission period. One received signal is compared with another received signal at a similar corresponding comparison periods in different transmission periods of a receiving time of the reflected wave. Switching between the comparison periods is performed each time the transmission period is updated. A waveform of a received signal in a block A0 corresponding to a reflected wave of an ultrasonic signal transmitted in a first transmission period is stored. The absolute values of differences between the waveform of a received signal in a block A1 corresponding to a reflected wave of an ultrasonic signal transmitted in a second transmission period and the stored waveform of the received signal in the block A0 are accumulated. The waveform of a received signal in a block B1 is stored.

Abstract: Systems and methods for providing audio localization are provided. In some aspects, a method includes receiving phase offsets of a plurality of fixed transmitters from a source other than the plurality of fixed transmitters, detecting an audio localization signal from each of the plurality of fixed transmitters, determining a received phase of the audio localization signal from each of the plurality of fixed transmitters, determining time differences of flight from the mobile receiver to the plurality of fixed transmitters using the received phases, determining distance differences from the mobile receiver to the plurality of fixed transmitters using the time differences of flight, and determining the location of the mobile receiver by performing multilateration using the distance differences.

Abstract: A sound direction estimation apparatus includes a sound source model storage unit that stores likelihood of a sound source class in correspondence with a sound feature quantity, a sound signal input unit that receives a sound signal, a sound source identification unit that identifies a sound source class of the sound signal input from the sound signal input unit with reference to the sound source model storage unit based on the sound feature quantity of the sound signal, and a first sound source localization unit that estimates a sound direction of the sound signal of the sound source class identified by the sound source identification unit.

Abstract: An analog to digital converter includes: a first pulse delay circuit forming a multi-stage delay unit of which each delay unit have a pulse signal delayed with a delay time responding to an input voltage; a first encoding circuit that detects the number of delay units in the first pulse delay circuit through which the pulse signal passes during a predetermined measurement period, and outputs the AD conversion data based on the number of delay units; and a timing generation circuit which, in response to receiving the start signal, generates an end signal when the input voltage of the first pulse delay circuit is a specified voltage within an allowable input voltage range, in order to determine the measurement period which is a time required for the pulse signal to pass through a predetermined number of the delay units which is specified in advance.

Abstract: An ultrasonic sensor includes a transmitting device, a receiving device, and a circuit device. The circuit device determines that the receiving device receives an ultrasonic wave reflected from an object, when an output voltage of the receiving device is equal to or greater than a first threshold. The circuit device includes a humidity detection section configured to detect an ambient humidity of the transmitting and receiving devices and a threshold adjustment section configured to calculate, based on the detected ambient humidity, a sound pressure of the ultrasonic wave that is received by the receiving device after propagating over a round-trip distance between the ultrasonic sensor and the object. The threshold adjustment section reduces the first threshold, when the output voltage corresponding to the calculated sound pressure is less than a second threshold that is greater the first threshold.

Abstract: A method and an apparatus for passive determination of target parameters by directionally selective reception of sound waves emitted or transmitted from a target, by an arrangement (24) of underwater sound sensors of a sonar receiving installation from estimated bearing angles determined from estimated positions of the target, and bearing angles measured at the measurement point by the arrangement (24). A bearing angle difference between measured and estimated bearing angles is iteratively minimized and, when the minimum is reached, the target parameters are used for an optimized solution for outputting target position, course, range and/or velocity and they are updated during each processing cycle in a series of successive processing cycles.

Abstract: An exemplary method of facilitating communication includes determining a position of a portable communication device that generates a video output. A sound output control is provided to an audio device that is distinct from the portable communication device for directing a sound output from the audio device based on the determined position of the portable communication device.

Abstract: An apparatus estimates the direction of a sound source from signals plural microphones capture sound to produce. Data are stored on reverse characteristics of spatial transfer functions defined on sound transmitted from sound source positions to the respective microphones. To the signal produced by each microphone, applied are the reverse characteristics of the spatial transfer functions thus stored in connection with that microphone with respect to the sound source positions to thereby estimate a sound source signal on a sound source position associated with the sound captured. Between the sound source signals estimated on the sound source positions associated with the sounds captured by the microphones, coincidence or higher correlation is found on a sound source position to thereby produce information on at least the direction of the sound source thus found.

Abstract: Methods and systems are provided herein for signal source tracking. A signal emitted over time from a moving source is a collection of small sub-signals that were emitted by the source at different positions along its path. If the source is traveling at a slower speed than the signal, the sub-signals will arrive at a given sensor in the same order that they were released. By identifying the locations and times of the releases of several of these sub-signals, the path and velocity of the moving source can be estimated.

Abstract: An apparatus for estimating a Direction of Arrival (DOA) of a wideband includes a first signal receiving unit and a second signal receiving unit to receive a wideband signal while satisfying d?Mc/2fs, wherein ‘d’ denotes a distance the first signal receiving unit and the second signal receiving unit are spaced apart from each other, ‘c’ denotes the speed of sound, ‘M’ denotes a number of wideband frequencies being a number of fast Fourier transformation (FFT) points of a wideband signal, and ‘fs’ denotes a sampling frequency, and a DOA calculating unit to calculate a DOA (?) using a normalized frequency ( f) which is obtained by performing an FFT on the respective wideband signals transmitted from the first signal receiving unit and the second signal receiving unit, and using the distance d.

Abstract: A distributed sensor network has a base station and clusters of sensor nodes. In a method of locating and classifying signal sources, at each node divides a received signal into blocks, performs Fourier-based transform on the blocks, selects peaks from the transformed blocks, selects subbands with features of interest based on the frequency of occurrence of the peaks across the blocks, collaborates with other nodes in the cluster to make a final selection of the subbands, encodes the subband features of the signal, and transmits the subband features to the base station. The base station processes the received subband features to locate and classify the signal sources.

Abstract: To enable precise calculation of a propagation time of a direct wave which arrives fastest from an ultrasonic generation source without being affected by a reflected wave of an ultrasonic signal. A plurality of ultrasonic signals generated based on a plurality of M sequences different from each other are propagated from a transmission side to a reception side, whereby the reception side generates model waveforms of the plurality of M sequences, executes correlation processing between each model waveform and a waveform of each ultrasonic signal and detects a secondary peak of a correlation value which appears when both waveforms partly coincide with each other to determine an M sequence which generates a smallest secondary peak among secondary peaks detected by all the correlation processing as an optimum M sequence.

Abstract: A computer implemented method for automatically detecting and classifying acoustic signatures across a set of recording conditions is disclosed. A first acoustic signature is received. The first acoustic signature is projected into a space of a minimal set of exemplars of acoustic signature types derived from a larger set of exemplars using a wrapper method. At least one vector distance is calculated between the projected acoustic signature and each exemplar of the minimal set of exemplars. An exemplar is selected from the minimal set of exemplars having the smallest vector distance to the projected acoustic signature as a class corresponding to and classifying the first acoustic signature. The first acoustic signature and the plurality of acoustic signatures may correspond to one of gunshots, musical instruments, songs, and speech. The minimal set of exemplars may correspond to a hierarchy of acoustic signature types.

Abstract: Systems and methods are disclosed associated with processing origin/location information of a source or event. In one exemplary implementation, there is provided a method of performing improved three-dimensional source location processing including constraint of location solutions to a two-dimensional plane. Moreover, the method includes obtaining a plane of constraint characterized as a plane in which the source is likely to occur, providing one or more virtual sensing elements each characterized as being located on a first side of the plane of constraint in a mirror image/symmetrical position across from a corresponding actual sensing element on an opposite side of the plane, and constraining possible origin locations to be located in the plane of constraint. Other exemplary implementations may include determining the origin location as a function of positions of the sensing elements and the virtual sensing elements as well as time-of-arrival and/or angle-of-arrival information.

Abstract: Sound and image are sampled simultaneously using a sound/image sampling unit incorporating a plurality of microphones and a camera. Sound pressure waveform data and image data are stored in a storage means. Then the sound pressure waveform data are extracted from the storage means, and a graph of a time-series waveform of the sound pressure level is displayed on a display screen. A time point at which to carry out a calculation to estimate sound direction is designated on the graph, and then sound direction is estimated by calculating the phase differences between the sound pressure signals of the sound sampled by the microphones, using the sound pressure waveform data for a calculation time length having the time point at the center thereof. A sound source position estimation image having a graphic indicating an estimated sound direction is created and displayed by combining the estimated sound direction and the image data sampled at the time point.

Abstract: A method and system for detecting and classifying intruders is provided. A noise threshold can be determined and set based on background noise. A seismic sensor can be configured to receive a plurality of seismic data signals. A microcontroller can be configured to count the number of times the noise threshold is exceeded over a defined time interval by the plurality of seismic data signals, and then detect and classify the presence of an intruder based on the count. Additionally, an amplitude evaluation module can be configured to determine a signal amplitude for the seismic data signals associated with the detected intruder and compare the detected intruder signal amplitude to known signal amplitudes in order to determine a sub-type of the intruder. Finally, a transmission source can be configured to transmit intruder detection and classification information to a remote location.

Abstract: A method for acquisition and processing of marine seismic signals to extract up-going and down-going wave-fields from a seismic energy source includes deploying at least two marine seismic energy sources at different depths in a body of water. These seismic energy sources are actuated with known time delays that are varied from shot record to shot record. Seismic signals from sources deployed at different depths are recorded simultaneously. Seismic energy corresponding to each of the sources is extracted from the recorded seismic signals. Up-going and down-going wave-fields are extracted from the sources deployed at different depths using the extracted seismic energy therefrom. A method includes the separated up-going and down-going wave-fields are propagated to a water surface or a common reference, the up-going or the down-going wave-field is 180 degree phase shifted, and the signals from these modified up-going and down-going wave-fields are summed.

Abstract: A survey method giving improvements in weapons fire location systems is disclosed. In an urban system with a distributed array in the midst of many buildings that block signal paths or create echoes, methods are provided to measure signal propagation. A survey or tour of the covered region uses a moving signal source to probe propagation inside the region. Survey results may indicate where more or fewer sensors are needed. Survey results plus current measured noise gives prediction of instantaneous system sensitivity. In addition, multipath propagation may be used to determine a location even when only one or two sensors detect the signal. In such exemplary cases, triangulation may be replaced or augmented by pattern recognition. Further, signals of the survey need not be acoustic impulses such as gunfire, but may be RF signals, or coded continuous signals so that gunfire-like sounds would not disturb citizens in the area.

Abstract: An acoustic sensor acquires acoustic data corresponding to a rotating component of a machine during operation of the machine. The acoustic sensor can be configured to enhance acoustic signals in a range of frequencies corresponding to at least one evaluated condition of the rotating component and/or enhance the acoustic signals received from a directional area narrowly focused on the rotating component. The rotating component is evaluated using the acoustic data acquired by the acoustic sensor. In an embodiment, the machine can be a vehicle traveling past a parabolic microphone. In a more specific embodiment, the vehicle is a rail vehicle and the rotating component is a railroad wheel bearing.

Abstract: A pen transcription system and method for locating a moveable signal source are disclosed. The transcription system includes a base having a planar base surface, first and second acoustical sensors that detect an acoustical signal emitted by a moveable signal source, the acoustical sensors being mounted on the base and separated from one another. The difference in time of detection between an EM signal and the acoustical signals is measured to determine the position of the moveable source. The acoustical sensors include a housing surrounding a detector. The housing has an aperture having a width that is less than the wavelength of said acoustical signal divided by 6.28 and a height that is substantially equal to an integer multiple of a wavelength of an interfering acoustical signal.

Abstract: A system for controlling signals coming from or going to an aircraft simulator has a first slave circuit and a second slave circuit. The second slave circuit is used to monitor signals coming from the aircraft simulator. A multiplexer circuit is coupled to the first slave circuit. The first slave circuit sends control signals to the multiplexer circuit for controlling digital output signals being sent to the aircraft simulator. A master controller is coupled to the first slave circuit and the second slave circuit. The master controller is used for controlling operation of the first and second slave circuit. A computer system is coupled to the master controller. The computer system will display a listing of the aircraft simulator signals to be controlled. Selection of a desired aircraft simulator signal by an input device of the computer system will allow one to control the selected aircraft simulator signal.

Abstract: A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.

Abstract: A system for three-dimensional tracking of high speed undersea projectiles may utilize a distributed field of randomly positioned passive acoustic sensors. The system measures variables related to the pressure field generated by a supercavitating projectile in flight wherein the amplitude of the pressure generated at a point in space is related to the projectile dimensions, velocity, and trajectory. The system iteratively processes data from the sensors to measure launch velocity, flight direction (trajectory), ballistic coefficient (drag), and/or maximum range.

Abstract: Mobile device localization using audio signals is described. In an example, a mobile device is localized by receiving a first audio signal captured by a microphone located at the mobile device and a second audio signal captured from a further microphone. A correlation value between the first audio signal and second audio signal is computed, and this is used to determine whether the mobile device is in proximity to the further microphone. In one example, the mobile device can receive the audio signals from the further microphone and calculate the correlation value. In another example, a server can receive the audio signals from the mobile device and the further microphone and calculate the correlation value. In examples, the further microphone can be a fixed microphone at a predetermined location, or the further microphone can be a microphone located in another mobile device.

Abstract: There is provided a sound source characteristic determining device (10) capable of being applied in an environmental where the type of a sound source is unknown. The device includes a plurality of beamformers (21-1 to 21-M) used when a sound source signal generated from a sound source at an arbitrary position in a space is inputted to a plurality of microphones (14-1 to 14-N), for weighting the acoustic signal detected by each of the microphones by using a function for correcting the difference of the sound source signals generated between the microphones and outputting a totaled signal. Each of the beamformers (21-1 to 21-M) contains a function having a unit directivity characteristic corresponding to one arbitrary direction in the space and is arranged for each of the directions corresponding to an arbitrary position in the space and the unit directivity characteristic.

Abstract: A personal water safety device includes at least three base stations, at least one water sensing device, and an alarm apparatus. The at least one water sensing device wirelessly communicates with each of the at least three base stations. The alarm apparatus wirelessly communicates with each of the at least three base stations. Each water sensing device is worn by a swimmer and is triggered to measure elapsed time when the swimmer submerges in water, and transmits the measured time to the at least three base stations. The alarm apparatus receives the measured time transmitted from each of the at least three base stations, and generates an alarm when the measured time of one of the at least water sensing device exceeds a predetermined time limit.

Abstract: A personal water safety device includes a barrel portion, and a base part. The base part connects two portions of a swimming goggle frame. The barrel portion includes a button, and a cylinder connected to the button via a spring. The base part includes a timer connected to the cylinder, and an alarm electrically connected to the timer. Water enters the cylinder when the button is pressed, and the timer measures an elapsed time when electrical conductivity of interior of the cylinder is in a predetermined range. The alarm generates an alarm when the measured time exceeds a predetermined time limit.

Abstract: A multi-sensor sound source localization (SSL) technique is presented which provides a true maximum likelihood (ML) treatment for microphone arrays having more than one pair of audio sensors. Generally, this is accomplished by selecting a sound source location that results in a time of propagation from the sound source to the audio sensors of the array, which maximizes a likelihood of simultaneously producing audio sensor output signals inputted from all the sensors in the array. The likelihood includes a unique term that estimates an unknown audio sensor response to the source signal for each of the sensors in the array.

Abstract: Estimating the proximity of an audio source is accomplished by transforming audio signals from a plurality of sensors to frequency domain. The amplitudes of the transformed audio signals are then determined. The proximity of the audio source is determined based on a comparison of the frequency domain amplitudes. This estimation permits a device to differentiate between relatively distant audio sources and audio sources at close proximity to the device. The technique can be applied to mobile handsets, such as cellular phones or PDAs, hands-free headsets, and other audio input devices. Devices taking advantage of this “close proximity” detection are better able to suppress background noise and deliver an improved user experience.

Abstract: An apparatus and method of voice activity detection (VAD) are disclosed. To detect a target sound, a target sound detecting apparatus calculates the phase difference corresponding to each frequency component from a plurality of sound signals converted in frequency domain, calculates a characteristic value indicating possibility that the phase difference of the frequency component is within an allowable phase difference range of target sound calculated based on a direction angle of the target sound, and detects the presence and/or absence of target sound using the characteristic value.

Abstract: There is provided a method of tracking an object in a three-dimensional (3-D) space by using particle filter-based acoustic sensors, the method comprising selecting two planes in the 3-D space; executing two-dimensional (2-D) particle filtering on the two selected planes, respectively; and associating results of the 2-D particle filtering on the respective planes.

Abstract: A system and method for estimating the direction of arrival of sounds. One method including the steps of: forming a reference signal; detecting sound with two or more spatially separated, directional or spatially separated directional, microphones to produce two or more output signals; calculating the relationships between each of the two or more output signals and the reference signal; and estimating the direction of arrival based on differences between the relationships.

Abstract: A system for small space positioning comprises a transmitting device, movable within an approximate range, configured for transmitting a modulated continuous wave, wherein the modulated continuous wave includes a carrier signal and a base-band signal, and a receiving unit configured for receiving signal (s) transmitted by the transmitting device and for determining a position of the transmitting device within the approximate range based on analysis of both the carrier signal and the base-band signal received from the transmitting device.

Abstract: A method comprising determining at least one first parameter, wherein the first parameter is dependent on a difference between at least two audio signals; determining at least one second parameter, wherein the second parameter is dependent on at least one directional component of the at least two signals; and generating at least one ambience coefficient value dependent on the at least one first parameter and the at least one second parameter.

Abstract: In accordance with some embodiments of the present disclosure, a process for determining a direction vector of a sound source is described. The process may be implemented to detect, by a first sound sensor, a first sound pressure of a sound wave propagated from the sound source, and detect, by a second sound sensor, a second sound pressure of the sound wave. The process may further be implemented to determine, by a processor, the direction vector of the sound source relative to the first sound sensor and second sound sensor, wherein the direction vector is based on the first sound pressure, the second sound pressure, and a first distance between a first physical location of the first sound sensor and a second physical location of the second sound sensor.

Abstract: Various embodiments of the present invention are directed to systems and methods for multimodal object localization using one or more depth sensors and two or more microphones. In one aspect, a method comprises capturing three-dimensional images of a region of space wherein the object is located. The images comprise three-dimensional depth sensor observations. The method collects ambient audio generated by the object, providing acoustic observation regarding the ambient audio time difference of arrival at the audio sensors. The method determines a coordinate location of the object corresponding to the maximum of a joint probability distribution characterizing the probability of the acoustic observations emanating from each coordinate location in the region of space and the probability of each coordinate location in the region of space given depth sensor observations.

Abstract: A signal wave arrival angle measuring device includes: an observation data vector generation section generating an observation data vector necessary for an angle measurement of a signal wave from an electrical signal having been converted at a sensor group converting the signal wave of an observation target to the electrical signal; an ESPRIT angle measurement processing section calculating an arrival angle of the signal wave from the generated observation data vector; an arriving signal wave estimation section estimating information other than the arrival angle of the arriving signal wave from an angle measurement processing process data of the ESPRIT angle measurement processing at the ESPRIT angle measurement processing section; and a reliability determination section determining whether or not an angle measurement result of the calculated arrival angle is correct based on an estimation result of the arriving signal wave estimation section, and excluding an erroneous angle measurement result.

Abstract: An acoustic treatment apparatus obtains a first output signal by performing filtering for forming a directivity in a first direction for received sound signals of sound receivers, obtains a second output signal by performing filtering for forming a directivity in a second direction different from the first direction for received sound signals of sound receivers, obtains a strength ratio between a strength of the first output signal and a strength of the second output signal, and estimates a sound source direction on the basis of the strength ratio.

Abstract: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture defined by an axis. The acoustical sensor has a reception function that is symmetrical about the axis and the axis is substantially perpendicular to the base surface.

Abstract: The invention relates to a method for localizing and tracking acoustic sources (101) in a multi-source environment, comprising the steps of recording audio-signals (103) of at least one acoustic source (101) with at least two recording means (104, 105), creating a two- or multi-channel recording signal, partitioning said recording signal into frames of predefined length (N), calculating for each frame a cross-correlation function as a function of discrete time-lag values (?) for channel pairs (106, 107) of the recording signal, evaluating the cross-correlation function by calculating a sampling function depending on a pitch parameter (f0) and at least one spatial parameter (?0), the sampling function assigning a value to every point of a multidimensional space being spanned by the pitch-parameter and the spatial parameters, and identifying peaks in said multidimensional space with respective acoustic sources in the multi-source environment.

Abstract: A method for short range alignment using ultrasonic sensing is provided. The method includes shaping an ultrasonic pulse on a first device to produce a pulse shaped signal and transmitting the pulse shaped signal from the first device to a second device, receiving the pulse shaped signal and determining an arrival time of the pulse shaped, identifying a relative phase of the pulse shaped signal with respect to a previously received pulse shaped signal, identifying a pointing location of the first device from the arrival time and the relative phase, determining positional information of the pointing location of the first device, and reporting an alignment of three or more points in three-dimensional space. Other embodiments are disclosed.

Abstract: Localization of remote devices by: the emission of pulses from acoustic transmitters, whose wavefronts propagate in the space region occupied by the remote devices and finally reach them; the emission of radiofrequency pulses from each remote device at the time of detection of the wavefront by an on-board microphone; the acquisition, by a radio base, of the radiofrequency signals propagating from the remote devices, to evaluate the arrival time delays proportional to the distance between the i-th acoustic source and the j-th remote device; the formation of a reception vector for each emission by the i-th source, this vector having a maximum length M equal to the number of remote devices and consisting of the sequence of distances obtained as the product of the reception times and the estimated sound velocity. These steps are repeated for all acoustic sources, to form N+1 reception vectors, to calculate the position of the device by solving derived matrix equations.

Abstract: To determine a position of a survey receiver used to measure a response of a subterranean structure to a survey signal, positions of the survey receiver as the survey receiver descends in a body of water to a surface are received from an acoustic ranging system. Measurement information associated with movement of the survey receiver is received from at least one sensor. Based on the measurement information from the acoustic ranging system and the at least one sensor, the position of the survey receiver at the surface once the survey receiver has reached the surface is computed.

Abstract: A pen transcription system and method for using the same are disclosed. The pen transcription system includes a receiver having first and second acoustical sensors mounted on a planar base and separated from one another, an EM detector, and a controller. The first and second acoustical sensors detect an acoustical signal at a first wavelength emitted by a moveable signal source. The EM detector detects an EM signal that is synchronized with the acoustical signal. The controller measures the difference in time of detection between the EM signal and the acoustical signals detected by the first and second acoustical sensors. The acoustical sensors include a detector and a housing surrounding the detector, the housing having an aperture having a maximum dimension that is less than the first wavelength divided by 6.28.

Abstract: A system and method is provided for estimating a trajectory of an incoming bullet based on the acoustics of the shock wave created as the bullet travels through the air. A first auditory signal representing a direct sound from the shock wave is recorded and its azimuthal direction is determined. Based on this azimuthal direction and other assumptions two possible bullet directions that can cause that shock wave are estimated. A second auditory signal representing a reflection of the shock wave as it travels through the air also is recorded and its azimuthal direction determined. The azimuthal direction of the ground reflection will lie between the azimuthal direction of the first auditory signal and the more correct of the two estimated trajectories, and thus can resolve the ambiguity in the estimated direction of the bullet source.

Abstract: A device includes a visual-feature detecting unit that detects a visual feature of a sound source based on an image and visual information thereof and outputs visually localizing information indicative of at least a direction thereof, an auditory-feature detecting unit that detects an auditory feature of the sound source based on a sound and auditory information of the sound source and outputs auditorily localizing information indicative of at least the direction thereof, and a sound-source detecting unit that detects a position of the sound source based on the visually localizing information and the auditorily localizing information.

Abstract: In a building environment, a distance associated with a building automation device is determined as a function of an interval or an inserted time delay between a wireless transmission of a signal and wireless reception of another signal. For example, a two-way communication is provided with an automatic interval or a desired time delay inserted before responding to a received transmission. By using two-way transmissions, the building automation devices may be free of clock synchronization. Acoustic signals may be used in a building environment to determine a distance. The building automation device may also use radio frequency information for communicating with other devices.

Abstract: Systems, methods, articles of manufacture and apparatus are disclosed to calculate distance from audio sources. An example method disclosed herein includes receiving, at the reference audio collecting device, a first radio frequency (RF) signal from the portable audio collecting device, in response to receiving the RF signal, storing ambient audio to a memory as reference data samples, each of the reference data samples associated with an indication of a respective time of acquisition, and receiving a second RF signal containing portable data samples of the ambient audio, each of the portable data samples associated with an indication of a respective time of acquisition.