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  • Research Article
  • Open Access

A High Performance Pocket-Size System for Evaluations in Acoustic Signal Processing

EURASIP Journal on Advances in Signal Processing20012001:748573

  • Received: 15 May 2001
  • Published:


Custom-made hardware is attractive for sophisticated signal processing in wearable electroacoustic devices, but has a high initial cost overhead. Thus, signal processing algorithms should be tested thoroughly in real application environments by potential end users prior to the hardware implementation. In addition, the algorithms should be easily alterable during this test phase. A wearable system which meets these requirements has been developed and built. The system is based on the high performance signal processor Motorola DSP56309. This device also includes high quality stereo analog-to-digital-(ADC)- and digital-to-analog-(DAC)-converters with 20 bit word length each. The available dynamic range exceeds 88 dB. The input and output gains can be adjusted by digitally controlled potentiometers. The housing of the unit is small enough to carry it in a pocket (dimensions 150 × 80 × 25 mm). Software tools have been developed to ease the development of new algorithms. A set of configurable Assembler code modules implements all hardware dependent software routines and gives easy access to the peripherals and interfaces. A comfortable fitting interface allows easy control of the signal processing unit from a PC, even by assistant personnel. The device has proven to be a helpful means for development and field evaluations of advanced new hearing aid algorithms, within interdisciplinary research projects. Now it is offered to the scientific community.


  • acoustic signal processing
  • digital signal processor
  • DSP assembler

Authors’ Affiliations

Siemens Audiologische Technik GmbH, Gebbertstraße 125, Erlangen, 91058, Germany
Georg-Simon-Ohm-Fachhochschule, P.O. Box 210320, Nüremberg, 90121, Germany


© Rass and Steeger 2001