Method For Siren Detection Based On Audio Samples

    公开(公告)号:US20180018981A1

    公开(公告)日:2018-01-18

    申请号:US15718524

    申请日:2017-09-28

    申请人: Waymo LLC

    摘要: The present disclosure provides methods and apparatuses that enable an apparatus to identify sounds from short samples of audio. The apparatus may capture an audio sample and create several audio signals of different lengths, each containing audio from the captured audio sample. The apparatus my process the several audio signals in an attempt to identify features of the audio signal that indicate an identification of the captured sound. Because shorter audio samples can be analyzed more quickly, the system may first process the shortest audio samples in order to quickly identify features of the audio signal. Because longer audio samples contain more information, the system may be able to more accurately identify features in the audio signal in longer audio samples. However, analyzing longer audio signals takes more buffered audio than identifying features in shorter signals. Therefore, the present system attempts to identify features in the shortest audio signals first.

    Subband block based harmonic transposition

    公开(公告)号:US09858945B2

    公开(公告)日:2018-01-02

    申请号:US15644983

    申请日:2017-07-10

    发明人: Lars Villemoes

    摘要: The present document relates to audio source coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), as well as to digital effect processors, e.g. exciters, where generation of harmonic distortion add brightness to the processed signal, and to time stretchers where a signal duration is prolonged with maintained spectral content. A system and method configured to generate a time stretched and/or frequency transposed signal from an input signal is described. The system comprises an analysis filterbank configured to provide an analysis subband signal from the input signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples, each having a phase and a magnitude. Furthermore, the system comprises a subband processing unit configured to determine a synthesis subband signal from the analysis subband signal using a subband transposition factor Q and a subband stretch factor S. The subband processing unit performs a block based nonlinear processing wherein the magnitude of samples of the synthesis subband signal are determined from the magnitude of corresponding samples of the analysis subband signal and a predetermined sample of the analysis subband signal. In addition, the system comprises a synthesis filterbank configured to generate the time stretched and/or frequency transposed signal from the synthesis subband signal.

    Audio signal correction and calibration for a room environment

    公开(公告)号:US09716962B2

    公开(公告)日:2017-07-25

    申请号:US15379830

    申请日:2016-12-15

    申请人: AMX LLC

    发明人: Fawad Nackvi

    IPC分类号: H04S7/00 G10L19/022

    摘要: Disclosed are an apparatus and method of processing an audio signal to optimize audio for a room environment. One example method of operation may include recording the audio signal generated within a particular room environment and processing the audio signal to create an original frequency response based on the audio signal. The method may also include creating at least two iterative filters based on at least two separate frequency ranges of the original frequency response, calculating an error difference between the frequency response modified by the at least two iterative filters and the original frequency response, and applying the error difference to the audio signal.

    AUDIO SIGNAL ENCODING AND DECODING BASED ON HUMAN AUDITORY PERCEPTION EIGENFUNCTION MODEL IN HILBERT SPACE

    公开(公告)号:US20170200453A1

    公开(公告)日:2017-07-13

    申请号:US15469429

    申请日:2017-03-24

    申请人: Lester F. LUDWIG

    发明人: Lester F. LUDWIG

    摘要: A computer numerical processing method for encoding and decoding audio information for use in conjunction with human hearing is described. The method comprises approximating an eigenfunction equation representing a model of human hearing, calculating the approximation to each of a plurality of eigenfunctions from at least one aspect of the eigenfunction equation, and storing the approximation to each of a plurality of eigenfunctions for use in encoding and decoding. The approximation to each of a plurality of eigenfunctions represents a perception-oriented basis functions for mathematically representing audio information in a Hilbert-space representation of an audio signal space. The model of human hearing can include a bandpass operation with a bandwidth having the frequency range of human hearing and a time-limiting operation approximating the time duration correlation window of human hearing. In an embodiment, the approximated eigenfunctions comprise a convolution of a prolate spheroidal wavefunction with a trigonometric function.