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SOUND PRESSURE LIMITATION FOR PORTABLE RADIOS

IP.com Disclosure Number: IPCOM000008945D
Original Publication Date: 1999-Jan-01
Included in the Prior Art Database: 2002-Jul-25
Document File: 1 page(s) / 44K

Publishing Venue

Motorola

Related People

Volker Martschink: AUTHOR [+2]

Abstract

This paper deals with safety precautions to pre- vent high levels of noise being radiated from portable radio equipment.

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MOTOROLA Technical Developments

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SOUND PRESSURE LIMITATION FOR PORTABLE RADIOS

by Volker Martschink and Egbert Lenger

INTRODUCTION

  This paper deals with safety precautions to pre- vent high levels of noise being radiated from portable radio equipment.

PROBLEM TO BE SOLVED

  High sound pressure levels may damage the ears. Therefore it is a requirement to either limit the audio level of a portable radio to avoid this, or to make the user aware of possible damage to their ears.

PROPOSED SOLUTION TO THE PROBLEM

  To protect the user of a portable radio from high sound pressure levels, the following technical solu- tion may be used:

  The portable radio will be equipped with a dis- tance sensor in the area of the speaker. This sensor will provide information on the distance between the radio and the head of the user. Subsequently the audio power will be automatically controlled to a suitable level dependent upon the distance to the ear. With the help of this circuit regulations in terms of safety will be achieved electronically.

  To limit any possible fail conditions, additional- ly a sensor may be equipped, which reacts on the temperature of the human body. This will make sure that the audio will not be turned down, while placing the radio anywhere on the desk, ground or close to any material, which will fool the distance sensor.

ABSTRACT

Automatic limitation of sound pressure level of handheld communication equipment.

81 Janunly 1999

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