He will say so, and you may disagree with him too - politely, of course!
你也可能会不同意他的看法——当然,你应该礼貌地告诉他。
if there is any effect of noise upon mental health it must be so small that present methods of psychiatric diagnosis cannot find it.
如果噪音对精神健康有影响的话,那也一定是微乎其微,以致现代的精神病诊断方法还发现不了。