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Audio DSP - Circuits and Systems (Digest No. 1993/219), IEE Coilloquium on

Date 16 Nov 1993

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Displaying Results 1 - 9 of 9
  • Sigma-delta modulation for audio DSP

    Page(s): 1/1 - 1/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    An automated procedure is presented for the design of high-order sigma delta single stage modulators for use with high-quality digital audio systems. Immediate application to data conversion is discussed, with the advantage of relaxed analogue component specifications due to the one-bit quantiser. Further, a novel application is presented, applying the relatively new technique of digital bitstream processing to a digital audio mixing structure. Initial simulations confirm the viability of this approach from a feasibility viewpoint, and the ultimate simplicity of the one bit signal format suggests considerable application opportunities in commercial digital audio products View full abstract»

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  • Synthesis of audio signals using the wavelet transform

    Page(s): 4/1 - 4/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    Discusses musical signals synthesis using the wavelet transform. After a brief consideration of wavelets and the discrete wavelet transform the authors go on to consider its implementation for creating musical sounds View full abstract»

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  • A digital signal processing audiometric workstation

    Page(s): 7/1 - 7/5
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    The authors report on the development of a digital signal processing audiometric workstation based on a standard IBM PC and Motorola DSP56001 processor. The current system has functionality to test a patient's hearing using pure tone testing, FM tones, bandlimited noise, speech and white noise signals. Unlike most consumer DSP audio systems, the workstation uses 24 bit digital signals, which are then converted to analogue signals in an effort to produce a dynamic range much wider than the 88 dB nominally achieveable with 16 bit systems. Aside from the low level DSP functionality, the audiometric workstation has also been designed to be very easy to use by developing a Windows 3.1 based interface to provide a virtual instrument by duplicating the controls of a standard audiometer on screen View full abstract»

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  • Low power signal processing for digital compact cassette

    Page(s): 5/1 - 5/7
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (440 KB)  

    The author discusses source coding in digital compact cassette systems to begin with. Philip's first generation chip set and its sub-band filter implementation are then considered as is the Philip's third generation chip set View full abstract»

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  • Development of a commercial digital amplifier

    Page(s): 3/1 - 3/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (252 KB)  

    The desire to produce a high quality digital power amplifier has been with people for a number of years, but the high cost of digital signal processing hardware has prevented a fully digital product from appearing. Advances in logic devices and digital signal processing have allowed a digital amplifier to become a reality. The present paper describes work under a Teaching Company Scheme between B&W Loudspeakers and Kings College London aimed at producing the world's first commercial digital amplifier. The aim is to produce an amplifier which has a THD and SNR better than 100 dB with respect to 0 dB. A modular system has been used View full abstract»

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  • Real world active noise cancellation using a multichannel DSP56001 system

    Page(s): 8/1 - 8/8
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    Reports on the design and the real time performance of a portable active noise cancellation (ANC) system based around a PC hosted 20 MHz Motorola DSP56001 processor with a 4 channel analogue I/O board connected to the real world via standard consumer audio components. The system uses multi-channel filtered-X and filtered-U adaptive LMS algorithms, and includes facilities for on-line system identification. The linear response of this ANC system has been tested over the frequency range 65-500 Hz to easily produce cancellation of 20-40 dB for single tones and sums of a few tones. The authors present the performance of the ANC system when used to cancel a number of real world noises View full abstract»

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  • Live network assessment using digital signal processing

    Page(s): 2/1 - 2/4
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    A measurement device is presented that objectively characterises an echo-path by monitoring the speech signals non-intrusively on the 4-wire part of an in-service telephony connection. The device has been implemented on a Motorola DSP56001 and original results in the form of echo-path parameters have been derived that can be used to assess the call quality as perceived by the end-to-end customers. The programmable DSP hardware has constrained the solution to using the least-mean-squares algorithm but novel strategies have been employed in order to optimise the convergence rate of the model View full abstract»

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  • Consumer audio DSP and Motorola's DSP56004 microprocessor

    Page(s): 6/1 - 6/8
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (476 KB)  

    The author begins by discussing the role of digital signal processing in consumer audio. He goes on to discuss the Motorola 56004 microprocessor which has been designed to simplify system design for products destined for the consumer audio market View full abstract»

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  • IEE Colloquium on `Audio DSP - Circuits and Systems' (Digest No. 1993/219)

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    The following topics were dealt with: audio digital signal processing, sigma-delta modulation, live network assessment, digital amplifier, signal synthesis, digital compact cassette, Motorola DSP56004 microprocessor, audiometric workstation, active noise cancellation with Motorola DSP56001 View full abstract»

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