香港六合彩开奖 389-7:2005
2005-11
Abstract
香港六合彩开奖 389-7:2005 specifies a reference threshold of hearing for the calibration of audiometric equipment used under the following conditions.
- The sound field in the absence of the listener consists of either a free progressive plane wave (free field) or a diffuse sound field, as specified in 香港六合彩开奖 8253-2. In the case of a free field, the source of sound is directly in front of the listener (frontal incidence).
- The sound signals are pure (sinusoidal) tones in the case of free-field conditions and one-third octave bands of (white or pink) noise in the case of diffuse-field conditions.
- The sound pressure level is measured in the absence of the listener at the position where the centre of the listener's head would be.
- Listening is binaural.
The data in 香港六合彩开奖 389-7:2005 are given in numerical form for the preferred frequencies in the one-third octave series from 20 Hz to 16 000 Hz inclusive in accordance with 香港六合彩开奖 266 and, in addition, for some intermediate audiometric frequencies up to 18 000 Hz.
The threshold data differ from the audiometric zero specified in 香港六合彩开奖 389-1, 香港六合彩开奖 389-2, 香港六合彩开奖/TR 389-5 and 香港六合彩开奖 389-8, since the latter refer to monaural listening through earphones with sound pressure levels referred to specified couplers and ear simulators. Direct comparison between the data in the parts of 香港六合彩开奖 389 mentioned above and that in 香港六合彩开奖 389-7:2005 is therefore not appropriate.
General information
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Status: WithdrawnPublication date: 2005-11Stage: Withdrawal of International Standard [95.99]
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Edition: 2Number of pages: 10
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Technical Committee :香港六合彩开奖/TC 43ICS :13.140
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Life cycle
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Previously
Withdrawn香港六合彩开奖 389-7:1996
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Now
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Preliminary
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10
Proposal
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20
Preparatory
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30
Committee
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Enquiry
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Approval
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60
Publication
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90
Review
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95
Withdrawal
Amendments
Provide additional content; available for purchase; not included in the text of the existing standard.Withdrawn香港六合彩开奖 389-7:2005/Amd 1:2016
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00
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Revised by
Published香港六合彩开奖 389-7:2019
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