Abstract: This invention provides methods and apparatus for focusing a hypersonic beam to control both a direction and depth of audible formation delivery. Signals that are delivered to each of a plurality of hypersonic transducer elements are adjusted in phase so that transmitted hypersonic signals are focused at a focal point anywhere in space. The focal point of a focused hypersonic beam may be used to scan a space of interest when used in a receive mode in a pinging process. When objects are detected, a focused hypersonic beam may be used to deliver audible information substantially only to a neighborhood of the detected object.

Abstract: Methods for splicing PCM audio frames form modified frames by appending to each frame either a portion of the next preceding frame or the next following frame. According to a first approach, splices are obtained by fading up and fading down a frame end and a frame appendage only at a splice point, and overlapping and combining to provide a crossfade at the splice. Alternatively, every frame end and frame appendage is faded up and faded down, overlapped and combined. A subtractive method of providing complementary fade-up and fade-down reduces rounding errors.

Abstract: A method and apparatus for characterizing the response of an electronic stethoscope. The sensor of the electronic stethoscope is held in contact with a test surface of a phantom. A shaker, which is coupled to a stinger rod that extends inside the phantom, is driven to produce internal vibrations in the phantom. Surface motion of the test surface of the phantom is measured using a surface accelerometer coupled to the test surface. Vibrations from the phantom are detected and an electric signal based on the detected vibrations is generated with the electronic stethoscope. A surface transfer function is calculated based on the measured surface motion and the electric signal to characterize the response of the electronic stethoscope.

Abstract: A method is proposed for automatically adjusting the filter parameters—center frequency, quality and amplification or attenuation—of at least one digital equalizer which is a component of a reproduction device for audio signals in a vehicle passenger compartment. To that end, first of all, the acoustical frequency response of the passenger compartment is ascertained. The inadequacies in the acoustics of the passenger compartment in the form of local maxima and minima in the measured frequency response are then determined. On this basis, the filter parameters are adjusted automatically so that at least a portion of these inadequacies is compensated. A reproduction device for audio signals for implementing this method is also proposed.

Abstract: The present invention relates to novel systems, methods, and circuits useful for achieving quality sound presentation in high-noise environments. Specifically, the present invention provides systems, methods, and circuits for processing audio signals. The present invention further provides methods for hard-programming adjustments into a multi-band equalizer that compensates for anomalies associated with an anticipated listening environment.

Abstract: In accordance with the invention, audio signals are specially processed for sound presentation in a high noise environment. The electrical signal representative of the sound is first subjected to equalization to preferentially reduce the magnitude of bass signals while increasing the magnitude of treble signals. The equalized signal is then compressed, and the compressed signal is subjected to “mirror image” equalization which increases the magnitude of bass signals while reducing the magnitude of treble signals. The resulting signal fed to the speakers provides a sound presentation of compressed volume range and a bass-rich sound spectrum. It is particularly useful for providing quality sound presentation in a high noise environment.

Abstract: A system for enhancing sound quality comprising a filter that square roots the instantaneous amplitude of frequencies in an input signal for generating artificial harmonics corresponding to said frequencies. The system can comprise an automatic level control that momentarily boosts the amplitude of artificially generated harmonics to emphasize attack transients occuring within the input signal.

Abstract: This invention addresses sound recording and mixing methods for 3-D audio rendering of multiple sound sources over headphones or loudspeaker playback systems. Economical techniques are provided, whereby directional panning and mixing of sounds are performed in a multi-channel encoding format which preserves interaural time difference information and does not contain head-related spectral information. Decoders are provided for converting the multi-channel encoded signal into signals for playback over headphones or various loudspeaker arrangements. These decoders ensure faithful reproduction of directional auditory information at the eardrums of the listener and can be adapted to the number and geometrical layout of the loudspeakers and the individual characteristics of the listener. A particular multi-channel encoding format is disclosed, which, in addition to the above advantages, is associated with a practical microphone technique for producing 3-D audio recordings compliant with the decoders described.

Abstract: A noise or vibration control system reduces a sampling rate and reduces a control rate to improve computation efficiency. The present invention permits the use of a sample frequency (fs) that is less than twice the frequency of interest (fd). The sensed signals are filtered to extract a particular frequency range with a lower bound given by (2n?1)*fs/2 and an upper bound given by (2n+1)*fs/2, where n is an integer chosen so that the frequency of interest (fd) is within the extracted frequency range. The control commands are also calculated at a reduced rate, which is dependent upon the bandwidth of the tone, rather than the absolute frequency of the tone. Rather than updating the control signals directly on the sampled sensor data yk as it enters the computer, the control computations are done on the harmonic components ak and bk, or equivalently on the magnitude and phase.

Abstract: A method and a device for computing sense data, which automatically compute data relating to feelings or senses generated by the human sensations by analyzing signals, such as audio signals, relating to the sensations. In the device, a MP3 decoder storing unit stores digital sound data which has been recorded using MP3 system. A decompression unit decompresses MP3 data which has been decompressed, and outputs as sound pressure value data at each frequency area. A sense data computation unit includes a feeling analysis unit and a rhythm analysis unit. The rhythm analysis unit obtains count of beats per unit time based on the sound pressure value data. The feeling analysis unit obtains a few kinds of feeling parameter values based on the sound pressure value data, determines the kind and level of feelings based on the value of feeling parameter and the count of beats per unit time, and writes the results thereof into a sense data accumulation unit.

Abstract: An audio signal processing system for a vehicle is disclosed. The vehicle has a plurality of audio output producing devices. The system includes an audio input circuit, a processor, an audio output circuit, and at lease one speaker. The audio input circuit receives a plurality of audio signals from the plurality audio output producing devices. The processor is in communication with the audio input circuit for combining the plurality of audio signals. The audio output circuit is in communication with the audio input circuit for receiving the combined plurality of audio output signals. The audio output circuit conditions the plurality of audio signals for output. The at least one speaker broadcasts the conditioned plurality of audio signals to a vehicle occupant.

Abstract: The present invention is a dual position hearing protection device. In one position, the device provides substantial sound attenuation and hearing protection. In the second position, an opening in the device permits sounds to enter the ear of the user relatively unobstructed. In the preferred embodiment of this invention the position of the device is changed simply by compressing the exposed end of the earplug.

Abstract: Methods and apparatus for recreating audio signals to sound as though the signals had been recorded in a different acoustic environment is provided. The methods and apparatus may include one or more inputs that receive an audio signal and an input that receives a selected acoustic environment signal, as well as processing circuitry that produces one or more output signals representative of the audio signal being played in the selected acoustic environment. The input, output and characterization signals may be processed and recorded to storage media, either individually or together. The circuitry may interface with other technology and circuitry or may be a complete stand-alone system.

Abstract: An object is to provide an automatic wind noise reducing circuit and an automatic wind noise reducing method, which are capable of coping with a multichanneling trend of audio signals, and improving performance as well as the degree of freedom in system design. Arithmetic units (26, 27, 28) obtain added signals of audio signals of audio channels excluding respective selected audio channels, which are selected so as to be different from each other. Arithmetic units (29, 30, 31) subtract respective added signals of the arithmetic units (26, 27, 28) from corresponding audio signals of the selected audio channels. The subtraction signals from the arithmetic units (29, 30, 31) are subjected to a band limit control and limited to a frequency band of a wind noise signal by LPFs (21, 23, 25).

Abstract: The present invention relates to a method, system and device for monitoring noise received by individuals operating in noisy environments. The device comprises a substantially credit card size housing and can be worn as a “badge”. The device includes a monitoring means for monitoring sound, and a display for displaying various noise parameter values, including a percentage value of cumulative noise dose received by the device. The device includes an input key which enables a user to select one of a plurality types of hearing protection equipment, so the user can indicate to the device the hearing protection equipment they are wearing. This enables the device to monitor compliance. The device also includes an input key enabling the user to acknowledge when an unallowable noise dose level has been reached.

Abstract: A MEMS directional sensor system capable of determining direction from a microphone to a sound source over a wide range of frequencies is disclosed. By utilizing a parallel filter bank that relies on a slow wave structure in a MEMS device, such as described herein, a very small microphone, on the order of a few micrometers, can be designed with unsurpassed ability to detect a sound source location.

Abstract: A speaker (100) having a diagnostic capability, as well as a circuit (101) and related methods (500) for performing speaker diagnostics based upon a driving-point impedance are provided. The speaker includes a flexible cone (104) and a voice coil (106) connected to the flexible cone for driving the flexible cone so as to convert electrical signals into sound. The speaker also includes a signal source (110) connected to the voice coil for supplying a test signal to the voice coil. The speaker further includes a signal sensor (112) electrically connected to the voice coil for sensing a response signal occurring in response to the test signal. Additionally, the speaker includes a condition determining module (114) for determining a driving-point impedance based upon the response signal and for comparing the driving-point impedance to a predetermined impedance to thereby determine a condition of the speaker.

Abstract: A portable system capable of receiving audio signals from one or more sources and reproducing the signals via speakers contained therein. The portable audio reproduction system can include a docking station or similar means for communicatively coupling an audio device to the portable audio reproduction system, thereby reducing desktop clutter and simplifying connecting the portable audio reproduction system with the audio device. The speakers of the portable audio reproduction system can preferably be received within a base portion of the system, thereby protecting the speakers during transport and reducing the overall size of the system for improved portability. External connections may also be provided, thereby enabling the portable audio reproduction system to receive audio signals from additional sources, and a mixer allows the system to reproduce signals from a portable audio device and an auxiliary source, such as a computer.

Abstract: An adaptive noise canceling system for extracting a desired signal, comprising an adaptive noise cancellation filtering circuit for suppressing noise from a first input signal using a second input signal as a reference signal, and generating an output filtered signal representing the desired signal; and an adaptive noise cancellation controller for receiving the first and second input signals and the output filtered signal, and generating an output control signal for controlling coefficients of at least one adaptive filter of the adaptive noise cancellation filtering circuit, comprising a silence detector unit for detecting whether an acoustical signal is present in the input signals and the output filtered signal, and generating a first output signal which indicates whether the acoustical signal is present; a signal detector unit for detecting whether the desired signal is present in the input signals and the output filtered signal, and generating a second output signal which indicates whether the desired si

Abstract: A sound emitting device for providing at least one new sonic or subsonic frequency as a by-product of emitting a waveform of at least two ultrasonic frequencies whose difference in value corresponds to the desired new sonic or subsonic frequency. The device includes a parametric emitting perimeter or plurality of emitter segments positioned around a central open section. This open section is structured with a diagonal width greater than a cross-sectional diagonal of the parametric emitting perimeter. An ultrasonic frequency signal source and sonic/subsonic frequency generator are coupled together to a modulating circuit for mixing an ultrasonic frequency signal with an electrical signal corresponding to the at least one new sonic or subsonic frequency. The modulator output is coupled to the emitting perimeter which comprises ultrasonic frequency emitting material for propagating the mixed waveform into air for demodulating the waveform to generate the at least one new sonic or subsonic frequency.