[al:新概念英语（四）] [ar:MP3 同步字幕版（英音）] [ti:Non-Auditory Effects of Noise] [by:更多学习内容，请到chazidian.com搜索“新概念”] [00:01.01]Lesson 25 [00:03.22]Non-auditory effects of noise [00:11.01]What conclusion does the author draw about noise and health in this piece? [00:18.19]Many people in industry and the Services, [00:21.21]who have practical experience of noise, [00:23.99]regard any investigation of this question as a waste of time; [00:28.67]they are not prepared even to admit the possibility that noise affects people. [00:34.56]On the other hand, [00:35.97]those who dislike noise will sometimes use most inadequate evidence [00:40.50]to support their pleas for a quieter society. [00:44.39]This is a pity, because noise abatement really is a good cause, [00:50.12]and it is likely to be discredited if it gets to be associated with bad science. [00:56.80]One allegation often made is that noise produces mental illness. [01:02.85]A recent article in a weekly newspaper, for instance, [01:06.37]was headed with a striking illustration of a lady in a state of considerable distress, [01:12.20]with the caption 'She was yet another victim, reduced to a screaming wreck'. [01:19.25]On turning eagerly to the text, one learns that the lady was a typist [01:24.54]who found the sound of office typewriters worried her more and more [01:28.84]until eventually she had to go into a mental hospital. [01:33.69]Now the snag in this sort of anecdote is of course [01:37.49]that one cannot distinguish cause and effect. [01:41.41]Was the noise a cause of the illness, [01:44.21]or were the complaints about noise merely a symptom? [01:48.33]Another patient might equally well complain [01:51.08]that her neighbours were combining to slander her and persecute her, [01:55.23]and yet one might be cautious about believing this statement. [01:59.87]What is needed in the case of noise [02:02.22]is a study of large numbers of people living under noisy conditions, [02:07.04]to discover whether they are mentally ill more often than other people are. [02:12.39]Some time ago the United States Navy, for instance, [02:15.93]examined a very large number of men working on aircraft carriers: [02:20.91]the study was known as Project Anehin. [02:24.65]It can be unpleasant to live even several miles from an aerodrome; [02:29.62]if you think what it must be like [02:31.43]to share the deck of a ship with several squadrons of jet aircraft, [02:35.96]you will realize that a modern navy is a good place to study noise. [02:41.52]But neither psychiatric interviews nor objective tests [02:45.92]were able to show any effects upon these American sailors. [02:50.67]This result merely confirms earlier American and British studies: [02:55.97]if there is any effect of noise upon mental health, [02:59.29]it must be so small that present methods of psychiatric diagnosis cannot find it. [03:05.82]That does not prove that it does not exist; but it does mean [03:10.57]that noise is less dangerous than, say being brought up in an orphanage [03:15.45]-- which really is a mental health hazard.