发明名称 |
Methods for generating auditory indicators |
摘要 |
Existing auditory warning systems are in general too loud and it is often difficult to distinguish between a number of different warnings. Further under different conditions warnings may change character due to masking by varying noise. A warning system is disclosed which is based on a microprocessor and waveforms for each warning sound stored in a ROM. The waveforms are read out to DACs and used to drive a loudspeaker by way of programmable attenuators. Each waveform is devised to have at least four quasi-harmonically related frequency components at a power level in the range 15 to 30 dB above threshold. In this way the sounds are distinctive and do not change character with varying noise levels below threshold.
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申请公布号 |
US4644327(A) |
申请公布日期 |
1987.02.17 |
申请号 |
US19830515501 |
申请日期 |
1983.07.20 |
申请人 |
NATIONAL RESEARCH DEVELOPMENT CORP. |
发明人 |
PATTERSON, ROY D. |
分类号 |
B06B1/02;G08B3/10;(IPC1-7):G08B3/00 |
主分类号 |
B06B1/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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