有的人把真实的现实当成玄学，只能说明这种人科学学习能力很差。

两个不同机器或器材置换后，有变化是绝对的事情，这根本无需浪费时间去争议。倒是机器还是人耳听觉更灵敏更靠谱，这个问题争论不休。我的看法是，讨论这个议题，必须设立前提条件！不设条件和不同档次的东西没法比。回避对方的前提条件，把对方推到极端条件去驳斥，是无知或耍赖的做法。
说换机器无用和换线无用（指听不出来），必须机器和线材都能达到一个相当高的水准，这是前提条件。两个输出功率差别很大的功放，用电炉线和电话线当电源线，推动灵明度很低的音箱，再播放大动态的交响乐，普通人都可以听的出来它们的差别。
但是，我们把所有参与比较的机器和线材的质量要求提高，必须都进入一个高水准的门槛，情况就不一样了，你可能就听不出差别了。而这个门槛就是工程师人为设计的，他们把人类听觉辨认能力极限的阈值，作为最低门槛，来设计“高保真”设备，保证失真不被人察觉。设备和线材失真度远远小于耳朵鉴别能力几个数量级，你再操心实在多余，这些工程师早都了如指掌不屑一顾。值得操心的是音箱、喇叭电声转换器材，因为它们的失真度和耳朵鉴别能力一个档次，都属于百分之几这个水平，值得操心的还有听音环境的影响，是巨大的。对这两个问题视而不见，对线材吹毛求疵的，基本还是玩HIFI的初级阶段，因为他不懂失真在哪里，何来HIFI“高保真”？
再说这个外国人的提法，不够严谨。功放仅增益相同，效果不能完全一样。最大不失真功率也是很重要的指标，影响效果。小信号播放增益相同的机器差别不大。但是大动态的音乐播放，要求功放的功率储备要足够大，才能推动有力和较小失真。而功率小，遇到大信号要失真而且软弱无力，听感差别还是明显的。所以说，这种机器比较一定要有前提，那就是各项指标都非常相似，没有明显短板，而且技术指标水准是业内人士认可（不是发烧友认可）。这样的机器互换，能听出来区别很难；如果某机器屡次被识别，那就是这台机器某项指标有特异，或故意为之或不合格。

本帖最后由 哈哈大校 于 2016-1-1 18:56 编辑

大功率不一定是更响吧，增益和功率貌似不是一回事
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雨后是什么类型的音箱？就就用来听人声，小提琴的，交响乐根本就不行！

这类型的音箱本身对功放的要求就低！

你去问问搭配atc音箱的功放有没有区别？

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卖轮胎的人说汽车发动机都没有区别的，我管你v4，v6，v12什么发动机都好，这轮胎就是耐磨，有谁能2年内把它用报废，我免费送4条！

人家是在推销轮胎做广告！

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原文是在2次用不同的放大器播放时，人们给出的正确答案比例更高（正确率64.4%），而2次如果用的是相同的放大器，则更容易答错（正确率38.3%）。





我学Jdai，我就不说，我憋着，看你出丑。之前说你逻辑有问题都算抬举你了，我收回。应该是识字能力有问题，离逻辑问题还远着呢。 本帖最后由 罗德琴科 于 2016-1-1 08:48 编辑

说没区别的都是不想再花钱的。
或者说差不多，自我安慰而已。

我想买的时候，绝对是有区别滴。。。给自己找个理由。
看透了。
因为这两种人，我都当过。

引用两篇源链接后面的评论。其实还有更多的，篇幅太长，懒得都引用了。如果你需要，俺还可以再接着引用。希望你的英文和统计学都足够好，可以看懂。不过从这些评论中可以看到，原作者所谓的“统计分析”有多扯淡。

第一篇：

Thinking about these numbers, I was startled to realize that Table 2 on p.15 implies a false-positive rate of about 62%. A false-positive is when the subject reports hearing a difference when the trial consists of two listenings to one amplifier. I had assumed that the same music played through the same amplifier would sound the same and that the subjects would report "different" only if they heard a difference, hence I expected a false-positive rate of zero.

An explanation for the high false-positive rate is subject-bias. Indeed, JA quoted a listener as saying "You have to care about whether there is a difference or not." Caring may be reflected in biased responses. The effect of listener bias on the results is dismissed in footnote 9 by what I consider handwaving, and footnote 8 describes a Chi-squared test that supports the audibility of differences in amplifiers with respect to guessing "different" 50% of the time. If the subjects are guessing "different" more than 50% of the time, and by chance, more than half of the trials use two amplifiers, then the expected results would show more than 50% of the responses are correct. For example, if subjects guess "different" 90% of the time and "same" 10%, and the trials have two amplifiers 90% of the time, the expected true-positive rate is 90% x 90% = 81%, and the expected true negative rate is 10% x 10% = 1%, for a total expected correct-response rate of 82%. Thus, a correct-response rate of more than 50% does not necessarily show audible differences—the success rate must be significantly more than the expected success rate due to (possibly biased) guessing. According to Table 2, there were 1134 + 758 = 1892 trials with different amplifiers, and 823 + 815 = 1638 trials with the same amplifier; thus, about 54% of the trials involved different amps. Thus, the question is: Are the results explained by biased guessing or is the success-rate significantly greater than would be expected by biased guessing?

The best estimate we have for listener bias is the false-positive rate: it should be zero, but Table 2 shows it to be 62% (that is, the number of incorrect A-A responses and B-B responses divided by the total number of "one amp" trials). Repeating the Chi-squared test mentioned in footnote 8 with a probability of guessing "different" of 62% (rather than 50%) and a probability of guessing "same" of 38% (rather than 50%) yields a Chi-squared statistic of 3.16, which is within a 95% confidence interval; that is, the results are most likely due to biased guessing.

The wealth of published data allows a deeper analysis: as there are two variables of two values (a "different" or "same" response, and "one amp" or "two amp" trial), a Chi-squared test with three degrees of freedom can be computed. If the results are due to biased guessing, the probability of a true-positive is the probability of guessing "different" when the trial has two amps: 62% x 54% = 34%, the probability of a false positive is (100%-62%) x 54% = 20%, true-negative = (100%-62%) x 46% = 17%, and false-negative = 62% x 46% = 29%. The Chi-squared statistic for these probabilities and the responses from the tests is 2.78, again within a 95% confidence interval.

In short, the data from the Stereophile blind listening test are most likely to be due to biased guessing rather than audible differences between amplifiers.

I don't necessarily like this conclusion—I have my biases, including a belief that some people can hear better than others. Such exceptional individuals may not be readily obvious from tests with a small number of trials per person, but such tests can be used to find people who are either able to distinguish between the sound of amplifiers or are "lucky coins." As such, I am disappointed by Michael Fremer's reluctance to continue with certain double-blind listening tests: we can conclude that either he is lucky or he can hear better than most people, and a few dozen additional blind trials would (probably) make clear which.—Kevin Willoughby, Framingham, MA

第二篇：

As an experimental psychologist, I was glad to see an attempt to apply some of the methods of my science to the issue of audible differences among amplifiers ("As We See It," Vol.12 No.7). While you did a great many things right in setting up this experiment, there are some serious flaws in your statistical analysis which have important implications for interpreting your results.

The basic problem is that your respondents were (as you sort of acknowledge in your footnote on p.17) biased to respond "different"—ie, that they could hear a difference between the amplifiers being compared. In fact, it can be calculated from your Table 3 that 2228 (approximately 63.1%) of the responses were "different." Given this fact, and the fact that overall the amps really were different on 53.6% of the trials, the expected performance by chance can be calculated as approximately 50.9%. (This calculation is based on the assumption that only the bias to respond "different," and not the actual situation, determines responses. The number of correct responses expected by chance is then 0.631 (the expected proportion of "different" responses) x 1892 total "different" trials, plus 0.369 (the expected proportion of "same" responses) x 1638 total "same" trials. (The result of this calculation is about 1798, or 50.9% of the total.) This may seem like a small variation from your assumed chance level of 50.0%. In fact, however, the overall percent correct of 52.3% does not differ significantly from the correct chance level of 50.9%. (The Chi-square with one degree of freedom is approximately 1.34.) Therefore, the data do not show a statistically significant tendency to discriminate between amplifiers—Larry Archibald's comment (footnote p.17) is right on the mark.

A second comment concerns the so-called "differences between ability to distinguish amp difference and ability to determine sameness." This apparent difference is simply an artifact of the bias to respond "different." As the calculations above show, the expected (by chance, given the overall bias) levels of performance for "same" and "different" presentations are 36.9% and 63.1% respectively—indistinguishably different from the obtained levels of 38.3% and 64.4% (Table 3). Thus, any "caviling about test conditions" might be rejected, but not on the basis of this huge apparent difference.

A third (and final) comment concerns differences among the musical selections. While I have not done any detailed calculations like those above for the individual selections (this seems likely to be futile, given the reduced statistical power when using just part of the sample), note that the bias to say "different" varies substantially—as percent correct for "different" goes up, the percent correct for "same" goes down. What may be really going on here is simply this: Audiophiles believe that some types of music are more likely to reveal differences than others, and adjusted their response biases accordingly.

The upshot of all of this is that your data do not demonstrate audible differences between the amplifiers tested, under the conditions arranged. In statistical terms, the null hypothesis of no difference cannot be rejected. However, it is important to note what this conclusion (and the preceding argument) does not mean:

1) It does not mean that your respondents were deliberately biased to respond "different";

2) It does not mean that the null hypothesis of no difference is true—simply that it cannot be rejected with an acceptable degree of probability on the basis of the current data;

and 3) it does not mean that the gist of (most of) the admirably restrained conclusions on p.20-21 are incorrect. I suspect the main lesson of this exercise in fact is just how difficult methodology for this kind of research really is.

By the way, I believe that there are real audible differences among amplifiers—though I'll probably never be able to afford most of those reviewed by Stereophile.—Rich Carlson, Ph.D., Pennsylvania State University, University Park, PA

我不相信别人会有这么rz。
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老兄那四个链接真乃定海神针。我本想把其中精髓要点归纳一下。后来看看形势诡异，就先按兵不动，守株待兔，钓鱼执法。嗯。很有必要。看看还有多少人自告奋勇往坑里跳的。

话说这些要点，对于思维成熟经验丰富且听音品位较高的hifi烧友并不是宇宙难题。前几年无忌这里曾经深入讨论过盲听话题了。当时我们几个人已经归纳出跟你这几个链接殊途同归的结论。哈哈哈。没想到，现在人心不古，发烧友鱼龙混杂，甚至好多下三滥都进来了。于是原本不是疑问的也搞成了天外奇谭。好吧。蒜泥狠。我不多说，我只静静地看着某些人继续装逼。

是啊，所以有了对你链接的种种忽略和可笑阐释，我再贴点HIFI Choice的有什么意义啊？那个还就是评价声音表现，又没有百分比和听对听错。

有这个闲心还不如多花时间指导学生论文去也。

你应该好好读读后面的读者来信。别尽按照自己的想法来解释数据。

总数据是没有问题的。而所谓的“详细分析”有一堆serious flaws。这个不止一封读者来信指出了。当然，不知道你的数学如何，能不能看明白。 本帖最后由 laopai 于 2015-12-31 12:06 编辑

我贴出来的也是盲测数据，是更具体的数据。你的50%是平均后的数据。写过论文的都知道，原始数据最重要。

所以我说盲目比盲听更可怕。

52.3%和64.8%和38.8%比，哪个更接近原始数据，哪个是处理过的？

你知道科学论文原始数据比归纳总结的更重要吗？

5次听对4次也是处理过的结论吗？

和没有科学素养的人讲事情，真还不如我那些学生，一讲就明白。

最后的问题是：你会读书吗？

我拉红的字，都是比你50%更接近原始数据的数据。

还要我接受这个结论，有你这样讨论问题的吗？

可笑之至。一上来要人接受结论就是心虚的表现。

大家不要光是看总体的统计数字。具体的统计也是很有意思的，甚至更有意义。

首先是，实际播放时2次所用的放大器是相同、还是不同，会影响判断吗？很有意思的是，统计数字表明，会的。在2次用不同的放大器播放时，人们给出的正确答案比例更高（正确率64.4%），而2次如果用的是相同的放大器，则更容易答错（正确率38.3%）。也就是说，人的耳朵更容易把2次相同的声音，误听成不同的声音，而2次真正声音不同时，则相对更有把握判断出来。这是第一个有意义的结果。

第二个问题是：音乐类型和分辨的能力有干系吗？是否在播放某些音乐时，人们更容易得到正确的回答？

答案是，有关系的！比如，弗雷的安魂曲（属于古典）、披头士的歌曲Penny Lane、钢琴独奏，人们就更容易给出正确的回答，而RR公司出品的鼓乐录音，正确率比较低。看来用打鼓来测试放大器，并不是如有些人想像的那么有效的。

说到底，这两台放大器在驱动B&W M801S喇叭时，究竟是声音相同、还是不同的呢？正确答案当然是——不同。问题只在于这个“不同”究竟如何反映出来，以及在盲听测试中能否反映出来。

90秒的每段音乐播放时间可能是一个因素。如果听更长的时间，人们会更为真切地感受到2台放大器的差异。主办这次盲听测试的人员自己曾仔细试听并对比了2台放大器的效果，很有把握地说，如果是长时间的聆听，那么2台放大器的声音是很不同的。起码来说，VTL 300W会耐听很多。但这种“耐听很多”是不可能在每次90秒钟就切换掉的测试中表现出来的。

60人挤满一屋子也是一个因素。这样拥挤的情况下，不可能每个人都处于较佳的聆听位置。

听觉疲劳更是一个因素。盲听时大家为了要取得正确回答，都是听得很专注的，很容易疲劳，这个“竞技”状态，和平时欣赏音乐时的松弛状态，是差异很大的。

在7次里听对6次、7次的人群里，有一些业内熟知的名字，包括音响设计师、杂志评论员。这些人能得到较高的正确率，也是说明问题的。

Stereophile杂志的著名写手Michael Fremer在另一次盲听放大器的测试中（涉及Crown、VTL、Threshold三种放大器），5次全部答对，不仅如此，他甚至试图写出具体放大器的名字（这不是盲听要求的），而且5次里写对了4次。


关于这次盲听测试，每个人可以有自己的看法和解读。这里我不说下去了。希望看到更多数据的，可以研究以下链接：http://www_stereophile_com/features/113

从经验角度，我只多说一句：假如简单地盲听了一下，辨别不出差别，就认为两样东西真是没有任何差别的，这是有问题的。更为靠谱的是在自己熟悉的系统和环境中，进行长时间的深入体验、体会。当然这里的“长时间”不是说要用上1个月，但至少几个小时的熟悉、了解，最好是用熟悉的各种音乐素材试听，是十分必需的。

本帖最后由 罗德琴科 于 2015-12-31 11:51 编辑

不要断章取义。全部贴出来好不好？为什么你总是按照自己的观点来曲解材料？细节很重要。富人和穷人平均下就能说明这个社会都是中产了吗？你看不到50%的准确率是由64.4%和38.3%构成的吗？你们这些人写过科学论文没有？或者读过没有？知道怎么使用和分析数据吗？
我帮你贴出来吧，自己看去。你是不是害怕看到这一段？自动屏蔽了？

大家不要光是看总体的统计数字。具体的统计也是很有意思的，甚至更有意义。

首先是，实际播放时2次所用的放大器是相同、还是不同，会影响判断吗？很有意思的是，统计数字表明，会的。在2次用不同的放大器播放时，人们给出的正确答案比例更高（正确率64.4%），而2次如果用的是相同的放大器，则更容易答错（正确率38.3%）。也就是说，人的耳朵更容易把2次相同的声音，误听成不同的声音，而2次真正声音不同时，则相对更有把握判断出来。这是第一个有意义的结果。

第二个问题是：音乐类型和分辨的能力有干系吗？是否在播放某些音乐时，人们更容易得到正确的回答？

答案是，有关系的！比如，弗雷的安魂曲（属于古典）、披头士的歌曲Penny Lane、钢琴独奏，人们就更容易给出正确的回答，而RR公司出品的鼓乐录音，正确率比较低。看来用打鼓来测试放大器，并不是如有些人想像的那么有效的。

说到底，这两台放大器在驱动B&W M801S喇叭时，究竟是声音相同、还是不同的呢？正确答案当然是——不同。问题只在于这个“不同”究竟如何反映出来，以及在盲听测试中能否反映出来。

90秒的每段音乐播放时间可能是一个因素。如果听更长的时间，人们会更为真切地感受到2台放大器的差异。主办这次盲听测试的人员自己曾仔细试听并对比了2台放大器的效果，很有把握地说，如果是长时间的聆听，那么2台放大器的声音是很不同的。起码来说，VTL 300W会耐听很多。但这种“耐听很多”是不可能在每次90秒钟就切换掉的测试中表现出来的。

60人挤满一屋子也是一个因素。这样拥挤的情况下，不可能每个人都处于较佳的聆听位置。

听觉疲劳更是一个因素。盲听时大家为了要取得正确回答，都是听得很专注的，很容易疲劳，这个“竞技”状态，和平时欣赏音乐时的松弛状态，是差异很大的。

在7次里听对6次、7次的人群里，有一些业内熟知的名字，包括音响设计师、杂志评论员。这些人能得到较高的正确率，也是说明问题的。

Stereophile杂志的著名写手Michael Fremer在另一次盲听放大器的测试中（涉及Crown、VTL、Threshold三种放大器），5次全部答对，不仅如此，他甚至试图写出具体放大器的名字（这不是盲听要求的），而且5次里写对了4次。


关于这次盲听测试，每个人可以有自己的看法和解读。这里我不说下去了。希望看到更多数据的，可以研究以下链接：http://www_stereophile_com/features/113

从经验角度，我只多说一句：假如简单地盲听了一下，辨别不出差别，就认为两样东西真是没有任何差别的，这是有问题的。更为靠谱的是在自己熟悉的系统和环境中，进行长时间的深入体验、体会。当然这里的“长时间”不是说要用上1个月，但至少几个小时的熟悉、了解，最好是用熟悉的各种音乐素材试听，是十分必需的。

本帖最后由 罗德琴科 于 2015-12-31 11:39 编辑

黑字部分说明已发展成为概率事件。
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