广播声压级问题

zxyc200x

ABS90米以下钢制船里对广播声压级的要求是要达到75dB，至少高于语音干扰声压级20dB.
这里的语音干扰声压级和环境噪音声压级有什么区别，如何测得语音干扰声压级？
求高手解释！

江海直达

个人认为就是背景噪声强度。很久没使用ABS规范，不很了解。不妨请贴出它们规范的原文，让网友学习。

江海直达

个人认为就是背景噪声强度。很久没使用ABS规范，不很了解。不妨请贴出它们规范的原文，让网友学习。LSA code相关要求是，声强比背景噪声高出十五分贝，最高不必超出一百一十五分贝。

shaoxun

原来江海是知识文库啊

zxyc200x

15.9 Public Address System (1 July 1998)
Vessels with the keel laid or in similar stage of construction on or after 1 July 1998 are to meet the following
requirements. Where a public address system is provided to supplement the general emergency alarm
required by 4-6-2/17.1.1, the public address system is to comply with subparagraphs 4-6-2/15.9.1 through
4-6-2/15.9.3, as follows:
15.9.1
The system is to be a loud speaker installation enabling the broadcast of messages to all spaces where
crew members or passengers, or both, are normally present, and to muster stations. The system is
to provide for the broadcast of messages from the navigation bridge and other places onboard, as may
be required by ABS, with an override function so that all emergency messages may be broadcast if
any loudspeaker in the spaces concerned has been turned off, its volume has been turned down or
the public address system is in use for other purposes.
The system is to be installed with acoustic marginal conditions and is not to require any action
from the addressee. The system is to be protected against unauthorized use.
15.9.2
With the vessel underway in normal conditions, the minimum sound pressure levels for broadcasting
emergency announcements in interior spaces are to be 75 dB (A) and at least 20 dB (A) above the
corresponding speech interference level.
15.9.3
The system is to be connected to the emergency source of power.
For passenger vessels, see 5C-7-5/13.15 of the Steel Vessel Rules.


描述如上文中粗体字部分，一直以为都是环境噪音，可是真正研究一下发现好像并不是这么回事。
段落选自Under_90m_2014  
Part  4  Vessel Systems and Machinery
Chapter  6  Electrical Installations
Section  2  Shipboard Systems

zxyc200x

江海直达 发表于 2016-5-14 17:23
个人认为就是背景噪声强度。很久没使用ABS规范，不很了解。不妨请贴出它们规范的原文，让网友学习。LSA cod ...

但是我们这里有跑过船的人说机舱的广播一般是在没动机的时候开了听的，顶多就是辅助通用报警，真正有事的时候都是依靠声力电话。所以这里的语音干扰声压级应该就是平时机舱人员交流产生的语音干扰，没有必要按照环境噪音理解，否则机舱广播的要求基本上没几条船能满足。

zxyc200x

江海直达 发表于 2016-5-14 17:23
个人认为就是背景噪声强度。很久没使用ABS规范，不很了解。不妨请贴出它们规范的原文，让网友学习。LSA cod ...

机舱噪声一般在105-110之间，高出15个就是120左右了，一般也没这么大的功率的扬声器啊，而且LSA也没说不能超过115啊。

江海直达

shaoxun 发表于 2016-5-16 15:39
原来江海是知识文库啊

太感谢你的夸奖，绝不敢当。要学的东西哦，太多了。

江海直达

zxyc200x 发表于 2016-5-17 09:18
15.9 Public Address System (1 July 1998)
Vessels with the keel laid or in similar stage of construc ...

确实ABS规范必LSAcode的要求高出一些。

183yyme

Speech interference level严格的来说并不是机舱人员发出的语音，而是环境噪音对人耳语音分辨能力的干扰等级。环境噪音可以在人耳感知的任何频率下，但是平常人类谈话的语音通常在500-2000Hz内，同一频率下的噪音对人与人之间的语言交流干扰最大。Speech interfaerence level要测算的话就是在当前的噪音下测出各频率噪音，在数个语音频率范围内算出加权平均数，通常和announcements的声压等级测算形式是一致的，这个一般都会有专业软件，属于声学的范畴了。
国内么糊弄糊弄，没几个人懂。