Audio signal processing

About: Audio signal processing is a research topic. Over the lifetime, 21463 publications have been published within this topic receiving 319597 citations. The topic is also known as: audio processing & Acoustic signal processing.

Audio calibration system and method

Abstract: Described herein is an audio calibration system and method that determines optimum placement and/or operating conditions of speakers for an entertainment system. The system receives an audio signal and transmits the audio signal to a speaker. A recordation of an emanated audio signal from each speaker is made. The system performs a sliding window fast Fourier transform (FFT) comparison of the recorded audio signal temporally and volumetrically with the audio signal. A time delay for each speaker is shifted so that each of the plurality of speakers is synchronized. The individual volumes are then compared for each speaker and are adjusted to collectively match. The method can align and move the convergence point of multiple audio sources. Time differences are measured with respect to a microphone as a function of position. The method uses any audio data and functions with background noise in real time.

Am compatible digital waveform frame timing recovery and frame synchronous power measurement

Abstract: In a broadcast system having a complex waveform of digital and analog segments, frame timing is recovered (290) and the frame synchronous power (284) of the digital portion of the composite AM compatible Digital Audio Broadcast (DAB) waveform is measured by examining a portion of the signal (284) The frame timing necessary for proper demodulation is recovered from the received signal (200), and a signal power measurement for scaling (242) is provided (294) The composite AM compatible DAB waveform is produced by a modulation method in which a digital representation of an audio signal is encoded together with an analog amplitude modulated (AM) signal and transmitted simultaneously in the same frequency channel

Decoding of binaural audio signals

Abstract: A method for synthesizing a binaural audio signal, the method comprising: inputting a parametrically encoded audio signal comprising at least one combined signal of a plurality of audio channels and one or more corresponding sets of side information describing a multi- channel sound image; and applying a predetermined set of head-related transfer function filters to the at least one combined signal in proportion determined by the corresponding set of side information to synthesize a binaural audio signal. A corresponding parametric audio decoder, parametric audio encoder, computer program product, and apparatus for synthesizing a binaural audio signal are also described.

Adaptive filtering for music/voice separation exploiting the repeating musical structure

Abstract: The separation of the lead vocals from the background accompaniment in audio recordings is a challenging task. Recently, an efficient method called REPET (REpeating Pattern Extraction Technique) has been proposed to extract the repeating background from the non-repeating foreground. While effective on individual sections of a song, REPET does not allow for variations in the background (e.g. verse vs. chorus), and is thus limited to short excerpts only. We overcome this limitation and generalize REPET to permit the processing of complete musical tracks. The proposed algorithm tracks the period of the repeating structure and computes local estimates of the background pattern. Separation is performed by soft time-frequency masking, based on the deviation between the current observation and the estimated background pattern. Evaluation on a dataset of 14 complete tracks shows that this method can perform at least as well as a recent competitive music/voice separation method, while being computationally efficient.

Method and system for switching among independent packetized audio streams

Abstract: The present invention provides a method and system for noiselessly switching between independent audio streams. Such noiseless switching preserves valid RTP information at the time of switch over. For established VOIP calls, the present invention can noiselessly switch audio from one audio source to another. A switch directs audio data from multiple audio sources to a network interface controller. The switch can be a cell switch or a packet switch. The audio sources can be internal audio sources and/or external audio sources. An egress audio controller controls the operation of internal audio sources, the switch and the network interface controller to carry out noiseless switching according to the present invention. Certain call events which involve additional audio trigger a noiseless switch over.