To all the phenomena who came here to say that an MP3 sounds immediately...

3/6 with AKG headphones right after entry level

Can I try listening with earphones?

I'm serious Simò, with the hardware quality I have it wouldn't change much anyway.

Let's try.

2/6

I thought better, sometimes one is in doubt for a "little", anyway these tests are interesting.

One thing, however, can be perceived quite clearly (but it also depends on the density of the sound, not just the means used), mp3 files seem to be slightly more "muffled," less clean on the mid/high frequencies.

I used the usual walkman earphones (the life-sentence kind) that Simone has already heard about.

But did you take the test? How many did you guess correctly?

I don't know if you remember that several users said that recognizing an MP3 from a Wave was child's play; they used to come here to act cool. The fact that on a test where you are made to listen to the same version in three different file types (where you can therefore make comparisons as many times as you want) it still produces errors is the indicator that MP3s, starting from bitrates of 192kBit, are already practically indistinguishable from uncompressed formats on their own. By 'on their own' I mean that if I let you listen to a song without there being other versions to make comparisons, no one would be able to recognize an Mp3 at least at 192kBit or Wave unless they got lucky as hell!

I studied the MP3 algorithm in MatLab and it is something crazy, guys... I have a text that explains the algorithm and implements it in MatLab; 129 pages of extremely complex text. Very high-level mathematics, computer science, physics, acoustics, and psychoacoustics fused together to determine an unrivaled compression system, at the limits of the impossible, and the after-compression sizes justify its complexity. I remind you that an mp3 file can maintain good quality with a final size 10 times smaller than that of the original file. There are no other compression algorithms that guarantee performance like that of the MP3.

Yes, I did it, I specified how many wavs I "recognized".

Years ago I read an article mentioning a young student, winner of a scholarship of about 70/100,000 dollars, who seemed to have in his hands the solution to compress mp3 further by 10 times.

There was talk of potential job opportunities in New York, but if one considers that about (it seems to me) 10 years or more have passed since then, evidently it wasn't that feasible.

4/6, but I definitely had some luck, also because I was listening and clicking a bit quickly with the TV in the background: I have some Grado sr60 (open-back), which are very linear and slightly emphasized around 2.5 MHz, truly sharp for hearing every tiny defect. In any case, there's not much to be done, 320 kbps is indistinguishable and I think I was just lucky; 192 maybe yes, I haven't caught a single one... it seemed darker to me and with a more confused stereo spread. I regretted not doing the test more carefully but maybe, if I had, it would have gone worse. And anyway Simone is right: without direct comparison, it is practically impossible to recognize a compressed file; and I also have a friend who swears up and down that he can recognize them on the fly... As if...

CromaDiBrera wrote:

I also have a friend who swears up and down that he can recognize them at a glance... But yeah, right...

Ahahahaha yeah sure, and what do they call him "the bat"?

Let's also assume that, barring exceptions like bats indeed, we are all a bit deaf to high frequencies: I did a small online test and I don't reach 17.5 kHz, but the average for my age (almost 50) is even lower. The famous 20,000 [Hz] can only be heard by three-year-old children living in a mountain hut, I think...

Oh yes, 20,000 is a utopia... Not even children can hear them. It is a limit chosen specifically to be wide to facilitate all the electronic issues related to audio, but no one hears 20,000. High frequencies are heard in relation to the stress endured by the ear. 17.5 kHz is an excellent listening range; it means your ears are still perfectly functional, you have probably always been careful not to stress them too much. I believe that if we perform the same test on today's youth, who all go to clubs every Friday and Saturday, it might be a miracle if they can still hear 15 kHz. It would be an interesting experiment to conduct...

me 3 out of 6 . . . with Sennheiser HD 590

i am a little proud to have caught the three where there is more acoustic "softness". Suzanne Vega first and foremost.

for the rest I am not happy: it has been some time now that I have suspicions about my ears

CromaDiBrera wrote:

i did a little online test

hi Croma

could you link the online test?.. Thank you.

hi Croma

could you link the online test?.. Thank you.

http://onlinetonegenerator.com/hearingtest.html

15.5 MHz

Ok, but rest assured because tests like these done this way only give you a rough idea (actually, very rough). Keep in mind that it depends heavily on the listening conditions and ambient noise. These tests should be performed in an anechoic chamber with calibrated instrumentation that is sufficiently "flat"; otherwise, they don't make much sense. If done in a room during the day, there are noises that mask [frequencies], and it is very easy to miss even 1500 / 2000 Hz; then again, it always depends on the amount of noise.

TheSimon wrote:

These tests should be performed in an anechoic chamber with calibrated and sufficiently "flat" instrumentation; otherwise, they don't make much sense.

Exactly right.

Then one has to agree on "what" is heard: beyond a certain point, I only hear the attack of the sound. If 15MHz entered my ears with a crescendo instead of suddenly, I wouldn't hear them at all.

Out of curiosity, I tried two pairs of headphones: a pair of Sony MDR-XD200 (which I've used since 2003, but almost no longer) and those CD player earbuds (the 'life sentence' ones, Simone knows what I'm talking about).

I should preface this by saying that here at my place, the noise from cars passing on the Tiburtina is constantly audible; in the evening, in particular, the passing can be felt even from 700/800 meters away (especially the tires of trucks). I have the hum (as muffled as it may be) of the refrigerator in the next room, I hear those talking in the apartment below mine, and various other noises in the house (there are no thieves at the moment).

Since I was 12/13 years old, but perhaps even before, I "suffer" from hypersensitivity to noise, and the situation has worsened with the stress of recent years; therefore, I expected to be able to hear "better" than it (apparently) seems.

Further preface: I have never exaggerated the volume during listening sessions; I am someone who pays attention to these things.

With both pairs of headphones, I was unable to perceive (for what a test done in this manner is worth) anything beyond 13.5kHz, perhaps even slightly less.

CromaDiBrera, just a few days ago I saw a video by 'fonderie sonore' in which the Grado SR60 were recommended, specifically for their listening precision.

Piccinesco wrote:

With both headphones, I wasn't able to perceive (for what it's worth, a test done this way) anything beyond 13.5mhz, perhaps even slightly less.

kHz... Otherwise you're a radio!

Anyway Maurizio, don't obsess over it; believe me when I tell you that these tests done at home have no meaning whatsoever. As I repeat to you, audiometric tests must be carried out inside an anechoic chamber where they keep you for 5 minutes even before starting the test specifically to let the ear rest. The instrumentation is very flat and calibrated for this type of test; let's just say it's not one of those headphones you find on the market for listening to music, don't pay attention to these things. I would ban these DIY home tests because most of the time they generate completely unjustified anxiety when compared later with specific exams performed with specific equipment.

I'll add one more thing... Not hearing high frequencies, especially at our age (we aren't ancient yet), can depend on a very simple earwax plug that acts as a low-pass filter given its size, which an ENT can remove in 10 seconds. If you have always been careful with volumes and are not a clubbing fanatic, there is no reason why your hair cells should be leveled to the ground; you can rest easy.

Yes, I've never been to a nightclub (I prefer, if and when it happens, quiet places; the Tiburtina is already enough as an open-air nightclub).

Moreover (something I have always thought and anyone can test), when you are out, for example on the metro, using earphones, you will notice that to listen to music whose volume level at home (or in a place where the influence of outside noise is reduced) might be at 2/3 "bars," you will have to turn it up to 8 or even 9/10, creating auditory stress (including the noise of the metro, people talking, those playing with inevitable dissonances that destroy you, etc.) that causes damage without one realizing the harm.

For this reason, even when I am out, I regulate my volume (with these earphones—the ones that are fashionable now annoy me, precisely because it's a fashion and if you wore them before, you were seen as an idiot).

I'm not obsessed, but I don't even take for granted that the brain is just there to suffer every intervention of ours as if nothing were wrong.