Abstract: A noise injection system adds comfort noise to an audio signal. The system includes a background noise estimator that determines a spectral content of a background noise associated with the audio signal. A comfort noise generator generates a comfort noise signal having a random phase. A gain circuit adjusts the comfort noise signal based on the spectral content of the background noise. A combining circuit combines a gain-adjusted comfort noise signal and the audio signal to generate an output signal.

Abstract: A media system has media file storage that includes two or more media files having substantially the same media content. The two or more media files have different playback characteristics. The media system uses the playback characteristics to select one of the two or more media files for playback.

Abstract: Suspendable interrupts are described that allow a processor to remain in an idle state for a longer period of time. Each suspendable interrupt defines a maximum delay value that specifies the maximum delay software associated with the interrupt can wait between a receipt of an interrupt signal associated with the suspendable interrupt and raising the interrupt for servicing by the software. The delay value allows suspendable interrupts to be masked when a processor is placed in the idle state if they can be dealt with at a next scheduled wake time of the processor, allowing the processor to potentially remain in the idle state for a longer period of time.

Abstract: A system includes a touchscreen display and an interface application. The interface application controls the touchscreen display to provide a container and a user interface control. The user interface control may be selected through manipulation of the touchscreen display in an area of the container proximate the user interface control. The user interface application identifies a user manipulation as a mouse movement in response to manipulation of the touchscreen display in an area of the container when the manipulation has a motion magnitude exceeding a threshold value.

Abstract: A noise reduction system includes multiple transducers that generate time domain signals. A transforming device transforms the time domain signals into frequency domain signals. A signal mixing device mixes the frequency domain signals according to a mixing ratio. Frequency domain signals are rotated in phase to generate phase rotated signals. A post-processing device attenuates portions of the output based on coherency levels of the signals.

Abstract: The system provides a technique for suppressing or eliminating tonal noise in and input signal. The system operates on the input signal at a plurality of frequency bins and uses information generated at a prior bin to assist in calculating values at subsequent bins. The system first identifies peaks in a signal and then determines if the peaks are from tonal effects. This can be done by comparing the estimated background noise of a current bin to the smoothed background noise of the same bin. The smoothed background noise can be calculated using an asymmetric IIR filter. When the ratio of the current background noise estimate to the currently calculated smoothed background noise is far greater than 1, tonal noise is assumed. When tonal noise is found, a number of suppression techniques can be applied to reduce the tonal noise, including gain suppression with fixed floor factor, an adaptive floor factor gain suppression technique, and a random phase technique.

Abstract: An adaptive noise modeling speech recognition system improves speech recognition by modifying an activation of the system's grammar rules or models based on detected noise characteristics. An adaptive noise modeling speech recognition system includes a sensor that receives acoustic data having a speech component and a noise component. A processor analyzes the acoustic data and generates a noise indicator that identifies a characteristic of the noise component. An integrating decision logic processes the noise indicator and generates a noise model activation data structure that includes data that may be used by a speech recognition engine to adjust the activation of associated grammar rules or models.

Abstract: An acoustic echo cancellation system buffers remote side signals to one or more storage areas. A delay controller filters and delays the remote side signals to correlate the remote side signals to local side signals. An acoustic echo cancellation core pulls the remote side signals from the buffer through a delay controller. A delay estimator generates an estimate of a delay between the buffered remote side signals and the local side signals. The delay estimator renders a confidence level that indicates a degree of likelihood for each potential match between delayed remote side signals and the local side signals. The acoustic echo cancellation core substantially cancels a portion of the echo or reverberation within the local side signals based on the estimate of the delay and the confidence level.

Abstract: A system detects a speech segment that may include unvoiced, fully voiced, or mixed voice content. The system includes a window function that passes signals within a programmed aural frequency range while substantially blocking signals above and below the programmed aural frequency range. A frequency converter converts the signals passing within the programmed aural frequency range into a plurality of frequency bins. A background voice detector estimates the strength of a background speech segment relative to the noise of selected portions of the aural spectrum. A noise estimator estimates a maximum distribution of noise to an average of an acoustic noise power of some of the plurality of frequency bins. A voice detector compares the strength of a desired speech segment to a maximum of an output of the background voice detector and an output of the noise estimator.

Abstract: A sub-band processing system that reduces computational complexity and memory requirements includes a processor and a local or distributed memory. Logic stored in the memory partitions a frequency spectrum of bins into a smaller number of sub-bands. The logic enables a lossy compression by designating a magnitude and a designated or derived phase of each bin in the frequency spectrum as representative. The logic renders a lossless compression by decompressing the lossy compressed data and providing lost data based on original spectral relationships contained within the frequency spectrum.

Abstract: A noise suppression system reduces low-frequency noise in a speech signal using linear predictive coefficients in an adaptive filter. A digital filter may update or adapt a limited set of linear predictive coefficients on a sample-by-sample basis. The linear predictive coefficients may be used to provide an error signal based on a difference between the speech signal and a delayed speech signal. The error signal represents an enhanced speech signal having attenuated and normalized low-frequency noise components.

Abstract: A system improves speech detection or processing by identifying registration signals. The system encodes a limited frequency band by varying the amplitude of a pulse width modulated signal between predefined values. The signal is separated into frequency bins that identify amplitude and phase. The registration signal is measured by comparing a difference in average acoustic power in a plurality of adjacent bins over time.

Abstract: A system is set forth comprising a processor and memory storage units storing software code. The software code comprises code for a scheduling system and for generating a plurality of adaptive partitions that are each associated with one or more software threads and that each have a corresponding processor budget. The code also is executable to generate at least one sending thread and at least one receiving thread which responds to communications from the sending thread to execute one or more tasks corresponding to the communications. In operation, the scheduling system selectively allocates the processor to each sending and receiving thread based on the processor budget of the adaptive partition associated with the respective thread. The scheduling system bills the processor budget of the adaptive partition associated with the sending thread for processor allocation used by the receiving thread to respond to communications sent by the sending thread.

Abstract: A system classifies the source of an input signal. The system determines whether a sound source belongs to classes that may include human speech, musical instruments, machine noise, or other classes of sound sources. The system is robust, performing classification despite variation in sound level and noise masking. Additionally, the system consumes relatively few computational resources and adapts over time to provide consistently accurate classification.

Abstract: A software application and an operating system may run on a computer, which includes a graphics card and a video display, where the graphics card is operable to render images to the video display, and the operating system includes a universal application programming interface (API) which supports hardware layers on graphics cards. The operating system may be operable to receive draw events via the universal API; determine what hardware layers are available on the graphics card, and what their parameters are; and respond to draw requests from the software application by rendering the draw requests selectively to any of the available hardware layers on the graphics card.

Abstract: An electronic data system comprises memory storage having stored data, file system software, and a transaction file. The transaction file is maintained by the file system software, and includes a plurality of transaction records corresponding to transactions that have been or are to be executed on one or more files and/or the or more directories of the file system. The file system software operates to organize and maintain the stored data in the files and directories and also to coalesce multiple transaction records meeting one or more criteria into fewer coalesced transaction records. The physical memory space required by the transaction file is reduced by the transaction record coalescing. The coalesced transaction records may be constructed so that they represent a logical result of applying each transaction record of a transaction record set in chronological order.

Abstract: A speech enhancement system enhances transitions between speech and non-speech segments. The system includes a background noise estimator that approximates the magnitude of a background noise of an input signal that includes a speech and a non-speech segment. A slave processor is programmed to perform the specialized task of modifying a spectral tilt of the input signal to match a plurality of expected spectral shapes selected by a Codec.

Abstract: The operation of a vehicle electronic module is influenced by vehicle-state received on a vehicle communication bus. The electronic module analyzes vehicle-state data that includes information about the vehicle's environment. The electronic module improves or maintains electronic module performance by adjusting communication processing parameters to improve driver or passenger communication.

Abstract: A speech enhancement system controls the gain of an excitation signal to prevent uncontrolled gain adjustments. The system includes a first device that converts sound waves into operational signals. An ambient noise estimator is linked to the first device and an echo canceller. The ambient noise estimator estimates how loud a background noise would be near the first device before or after an echo cancellation. The system then compares the ambient noise estimate to a current ambient noise estimate near the first device to control a gain of an excitation signal.

Abstract: A speech enhancement system improves speech conversion within an encoder and decoder. The system includes a first device that converts sound waves into operational signals. A second device selects a template that represents an expected signal model. The selected template models speech characteristics of the operational signals through a speech codebook that is further accessed in a communication channel.