Can we trust our ears?

[restorer-john]

Oh, I've never tried it.

But I saw some people do it once at Burning Man.

Licking frozen toads? We have heaps of them here- Cane Toads (Bufo Marinus)

 

[watchnerd]

Licking frozen toads? We have heaps of them here- Cane Toads (Bufo Marinus)

No, live ones.

 

[Wombat]

Cane Toads produce the hallucinogen Bufotenon.

https://www.sbs.com.au/news/thefeed...-are-using-cane-toads-get-hallucinogenic-high

 

[watchnerd]

Cane Toads produce the hallucinogen Bufotenon.

https://www.sbs.com.au/news/thefeed...-are-using-cane-toads-get-hallucinogenic-high

I'm envisioning a bar with a 'tasting flight' consisting of American and Australian toads...

 

[Sal1950]

Oh, I've never tried it.
But I saw some people do it once at Burning Man.

Isn't that what Clinton said?
Or something very similar. LOL

 

[Sal1950]

Cane Toads produce the hallucinogen Bufotenon.

https://www.sbs.com.au/news/thefeed...-are-using-cane-toads-get-hallucinogenic-high

Ah, another expert. LOL

 

[trl]

Yes Sir, I do trust my own ears @ 42 years...and counting.

Got some audiocheck.net tests myself these days at an average-to-loud (no SPL-meter, sorry):

- https://www.audiocheck.net/audiotests_mosquito.php - crazy ass mosquito is trying to kill my only neuron left! I instantly stop it playing...so 17.4 KHz is pretty loud to my ears, but only when using speakers; with headphones I can't actually hear the mosquito...it's like I know it's there, but it's not "disturbing" my ears at all. I'll dig into this some other day perhaps (haven't tested with IEMs yet, but don't think it will change anything).
- https://www.audiocheck.net/audiotests_frequencycheckhigh.php - on speakers I was starting to hear from 19 KHz, when getting lower to 18-17 KHz makes me cover my ears with my hands, though at 8-9 KHz it sounds probably louder, but it's not so uncomfortable. With headphones, the max. audible frequency was 16 KHz...kinda strange after all, but I'll dig into this some other day perhaps (haven't tested with IEMs yet, but don't think it will change anything).
- http://www.ultrasonic-ringtones.com/ - on speakers I have no issues hearing the 18.8 KHz and everything else below, of course (I can't hear the 19.9 KHz at all). It's like few dB lower then other frequencies, but not with a huge margin, because my hands were getting onto my ears after the third test consecutive done @ 18.8 KHz. Also, the 17.7 KHz I hear it quite loud and seems that is bugging me much more than the 8 KHz...it's like driving me crazy. On headphones, as per above wrote, the first tone I can hear from this test is 15.8 KHz, though there's some feeling I get something around 17.7 KHz, but can't be sure it's my imagination or just some very low-level harmonics.
- https://www.audiocheck.net/soundtests_headphones.php - on speakers I didn't got more than 66 dB, environment was not very quiet and my 25 cm away desktop with its 8 fans wasn't helping me much either. However, on my closed-back AKG 550 things were much improved and now I can perfectly understand "72 dB below full scale", I can barely understand male voice words "78 dB below full scale" and I can hear that someone is speaking but can't understand what @ "-84 dB below scale". At "90 dB below scale" it's kinda silent in my head...sorry; after increasing the volume to very-loud I was able to get the words clearly, but that's insane so it doesn't counts.
- https://www.audiocheck.net/blindtests_frequency.php - I only got 14 KHz here, sorry. Test was done with AKG K550; on speakers I found the noise as being too disturbing and didn't felt it could be more reveling than with headphones.
- https://www.audiocheck.net/blindtests_level.php?lvl=0.5 - I found this test very interesting, although I had a feeling that the -0. 5dB tone had a higher intensity (-0.3 dB or -0.2 dB perhaps), but it was probably my imagination. However, I got 10 out of 10 here with 100% accuracy. With the 0.2 dB test I got lot of troubles with the -0.2 dB tone...so I find that one as being too difficult for my ears.
- https://www.audiocheck.net/testtones_subwooferharmonicdistortion.php - I get something starting with 24 Hz and the 28 Hz is quite beefy, but depending on the headphone used, depth and impact was different, but at least it was clearly audible. With speakers I got different results, because my MR10Smk3 refused to play frequencies lower than 30-32 Hz, have no idea why. At least my CANTON GLE 496 had no problems here, so I'm quite happy after all.
- https://www.audiocheck.net/audiotests_frequencychecklow.php - same as above.

Some screenshots attached as well.

Tests were conducted on:
- Mackie MR6mk3 + Mackie MRS10mk3
- CANTON GLE 496 (no sub)
- AKG K550, AKG K701, Beyerdynamic DT880 600 Ohms- balanced
- FOSTEX T50RPmk3, Hifiman HE-560, GRADO SR60i - single ended

Sources used:
- ASUS Essence One MKii Muses + Matrix M-Stage HPA 3B - for balanced cans only
- BURSON PLAY (w/LPSU) - for single ended cans only
- Pioneer A-209R, BURSON BANG

P.S.: Some of the above equipment are less or more modded, same applies to some of my cans as well: K550, DT880 and T50RPmk3 have a bit of dumping stuff inside to reduce unwanted vibrations, K701 has "bass-port mod" & "theaudiophileworld mod", SR80-i is having L-cushion & front grills replaced with soft and thin fabric.

Later Edit: I was able to do a hearing test with ASUS Xonar U7 + Beats Solo 2 closed back headphones, results here; seems that my hearing is still OK, around 0 dB loss. Volume was low, carefully calibrated per Audiocheck's recommendations, but inside the room was very quite anyway and this helped a lot.

Seems that the ASUS U7 + Solo2 setup is more helpful for the trebles, not sure if headphones linearity or the way cans are sitting on my ears, but I was able to hear trebles up to 18 KHz. However, still my speakers blow away all the cans I have (with speakers I can hear 19KHz better than I can hear 17 KHz with Solo2).

Tests done tonight to check high-end hearing:
- http://www.noiseaddicts.com/2009/03/can-you-hear-this-hearing-test/- mild hearing @18 Khz, acceptable hearing @ 17 KHz
- https://www.noisehelp.com/ultrasonic-ringtones.html - I can definitely get the 17. 4KHz mosquito, much lower than 8 KHz or 10 KHz, but at least with Solo2 cans I can hear up to 18 KHz.

Tests done tonight to check low-end hearing:
- https://www.audiocheck.net/testtones_subwooferharmonicdistortion.php - 20 Hz are mildly audible, from 30 Hz and above the impact is maxim.
- https://www.audiocheck.net/audiotests_frequencychecklow.php - same as above, but 20 Hz is having even a better impact, probably more higher harmonics in the sound.
- https://www.audiocheck.net/testtones_sinebursts20-200.php - same as above.

Great cans Solo2, indeed...unbelievable great bass response with trebles extension higher than any of the above headphones...and all of that coming from ASUS Xonar U7 (with LME49726 on outputs) connected to a Lenovo X230 laptop.

 

[trl]

I did some listening tests last night on the Stereophile Test Disc #02 with 500 Hz perfectly clean sinewave vs. same 500 Hz frequency but with added 2nd, 3rd and 7th harmonics at -60dB difference from the original signal (different track for each harmonic). I was using ARTA connected to RCA DAC ouputs to see when the higher harmonics bumps in, while listening to the 6.3mm headphones plug with my FOSTEX T50RP MK3 planars.

I was unable to discern any difference in sound from the original signal vs. the modified signal with added -60dB 2nd harmonic. Same applies to the 3rd harmonic as well. For the 7th harmonic test I was able to hear a bit of "spark" in the sound, so I'm inclined to say that 7th harmonic @-60dB will get somehow audible. However, -60dB means 0.1% THD, so quite high for a decent amplifier; usually, at 50% of max. output power most amps are providing harmonics lower than -80dB, so definitely inaudible to our ears, but easy to spot on measurement graphs.

I will do again these tests, but with different headphones, perhaps I'll get "more lucky" and spot a difference for the 2nd or at least 3rd harmonic @-60dB. Meanwhile, I invite everyone to perform this test; if not able to get the Stereophile test, I'm sure there are similar tests on the Internet or Adobe Audition to generate such files. Same invite applies for the audiocheck.net blind tests, especially the dymanic range tests...really interesting test.

P.S.: Just realized that tracks #24 and #25 seem to be more interested...I'll definitely give'em a try next night. I invite you all to do the same, because it's better to make a good correlation between measurements an what our ears are actually listening.

P.P.S.: On Stereophile graphs there are representations of 1%, 2% and 3% THD signals, but not of 0.1% THD I've tested. Of course, 1% THD gets audible, no matter it's about 2nd or 3rd harmonic.

 

[AnalogSteph]

Going by results of the 1960 Bryan & Parbrook study, you're probably not going to have much luck detecting 2nd at -60 dB - they didn't get below 52 dB (fundamental = 360 Hz). 3rd you just might, they got to -62 dB @ 70 dB SPL. 7th should be near the hearing threshold at this frequency and detected rather easily.
This is what I found myself years ago:

I conducted the most simple experiment possible, using Audacity for tone generation and level adjustment and my trusty Sennheiser HD580 headphones connected to a Terratec Aureon Sky soundcard for listening. As expected, a 440 Hz tone's 2nd harmonic at -40 dB was detectable but by no means strong, only giving the signal some "grit". It was definitely gone 20 dB below this level. 3rd, easily detected at -40 dB, had also gone by -60 dB. So far, it seems I'm a slightly worse "distortion listener" than the people on those studies, which does not surprise me.
Now the higher ones: 5th was just barely audible at -60 dB, as was 6th. 7th and 8th were still audible at -70 dB, requiring fairly high listening volume already (fundamental amplitude 0.8, Prodigy 7.1 driver main volume 43%, headphone channel gain -6 dB).

Intermod may be a different story. Masking is in part related to nonlinearities in the auditory system, but that's not all of it by far. I bet -60 dB of 2nd-order intermod would be easily detected with a CCIF test tone - not many people can hear 19 & 20 kHz at all, but the resulting components would be 39 kHz (inaudible) and 1 kHz.

 

[trl]

Good stuff, thanks for posting...now seems that I'm not the only one unable to "fell" 2nd and 3rd harmonics if below -60dB.
I'll do a multiple harmonics hearing test today, to summarise more harmonics, from 2nd up to...perhaps 7th; this should probably be audible somewhere around -40...-50dB I guess...I'll see later today.

Thanks again for your findings!

 

[andreasmaaan]

Keep in mind that masking is very level dependent. The statement "I can/can't detect 1% 2nd harmonic distortion of a 360Hz fundamental" is incomplete really. You need to specify the level of the fundamental because the detection threshold changes so much depending on it.

To illustrate, this shows how dependent the masking threshold is for a 1KHz fundamental on level (from Zwickl and Fastl):

At 90dB you'll have no hope of hearing 1% 2nd HD. At 60dB you'll be almost certain to hear it. And higher order harmonics are even more sensitive to level of the fundamental.

 

[trl]

I'm aware of that, thank you very much for sharing this info; this also explains why I couldn't pick up 2nd and 3rd harmonics @-60dB, but I could get the 7th harmonic. However, I've started listening at moderate level for the first few minutes, then increased to higher levels (about 90dB), so I can pick up the harmonics in both circumstances.

I've also done this test differently, last year: crank up the volume till pretty high level (I've used a 440Hz and 1KHz sinewaves to adjust the level to my ears), then played different frequencies at different levels (usually 440Hz or 1KHz at levels below -70dB). Below -80dB was very hard to pick up something and below -85dB it was almost impossible, and this test was done with perfect sinewaves (no harmonics added) playing at very low levels, so without masking. However, below -90dB I couldn't pick up anything, no matter what headphones I've used. Probably increasing the volume to the absolute max. supportable limit of my ears will improve the dynamic a little bit more and I might pick up -90dB or even -92dB levels, but not sure if it's worth...and it's not fair, because I'm not listening to such insane "absolute max. supportable limit of my ears" anyway.

Test sinewaves I got them from audiocheck website, but there're lot of trusted website to find those sines anyway.

If anyone else can take a similar test, would be great to share the experience. Who knows, maybe there's a "golden ear" hidden somewhere inside this forum that might pick up even -100dB.

 

[andreasmaaan]

I've also done this test differently, last year: crank up the volume till pretty high level (I've used a 440Hz and 1KHz sinewaves to adjust the level to my ears), then played different frequencies at different levels (usually 440Hz or 1KHz at levels below -70dB). Below -80dB was very hard to pick up something and below -85dB it was almost impossible, and this test was done with perfect sinewaves (no harmonics added) playing at very low levels, so without masking. However, below -90dB I couldn't pick up anything, no matter what headphones I've used. Probably increasing the volume to the absolute max. supportable limit of my ears will improve the dynamic a little bit more and I might pick up -90dB or even -92dB levels, but not sure if it's worth...and it's not fair, because I'm not listening to such insane "absolute max. supportable limit of my ears" anyway.

Also keep in mind that all of this is relative to the level produced by an "0dB" signal on your setup at your ears. So in other words it's all dependent on the voltage output of your amp and the sensitivity of your headphones/speakers, not to mention the ambient noise levels in your listening environment.

The graph in my previous post is based on data generated in an extremely quiet listening environment with the fundamental level measured at the listening position. In reality, nobody has such a quiet environment in their homes, studios, etc. But FWIW the dotted line on that graph shows the absolute threshold of audibility in quiet, and implies that in such conditions, as low as -10dB is audible in the 2-5KHz range to anyone with normal hearing, so long as there is no masking present. This -10dB is about 130-140 dB below the pain threshold.

 

[trl]

Exactly, it all depends on the "0dB" we choose for our ears, which in my case was pretty high, but not gone to extreme for sure.

I've used closed cans (AKG K550 and Beats Solo2) at 1 AM in the morning, background noise was unmeasurable with my phone app (probably 20dB of loudness). In my bedroom, at night, there're absolutely no background noise; I leave at home, very quiet neighbourhood (for now)...and outer isolation is pretty good.

 

[Blumlein 88]

I'm aware of that, thank you very much for sharing this info; this also explains why I couldn't pick up 2nd and 3rd harmonics @-60dB, but I could get the 7th harmonic. However, I've started listening at moderate level for the first few minutes, then increased to higher levels (about 90dB), so I can pick up the harmonics in both circumstances.

I've also done this test differently, last year: crank up the volume till pretty high level (I've used a 440Hz and 1KHz sinewaves to adjust the level to my ears), then played different frequencies at different levels (usually 440Hz or 1KHz at levels below -70dB). Below -80dB was very hard to pick up something and below -85dB it was almost impossible, and this test was done with perfect sinewaves (no harmonics added) playing at very low levels, so without masking. However, below -90dB I couldn't pick up anything, no matter what headphones I've used. Probably increasing the volume to the absolute max. supportable limit of my ears will improve the dynamic a little bit more and I might pick up -90dB or even -92dB levels, but not sure if it's worth...and it's not fair, because I'm not listening to such insane "absolute max. supportable limit of my ears" anyway.

Test sinewaves I got them from audiocheck website, but there're lot of trusted website to find those sines anyway.

If anyone else can take a similar test, would be great to share the experience. Who knows, maybe there's a "golden ear" hidden somewhere inside this forum that might pick up even -100dB.

Not quite the same thing. I had a few test files in a thread on noise floors once. (I don't think those files are up for download currently). I put noise into a clean file at various levels and asked everyone to say when it was inaudible. I asked they start with enough noise they heard it clearly. This while listening to music at their normal levels. Most results were -75 to -80 db for most who responded if my memory isn't shot.

The thing with higher harmonics is somewhat related to masking and sensitivity of the ear. If you were using 500 hz tones, the 7th harmonic is at 3500 hz. That is high enough it will not be masked by the fundamental. It will be near the most sensitive frequency of your hearing, and it might be heard at around those -60 db levels. If you were using 2 khz fundamentals, then 7th harmonic is still unmasked, but is at 14 khz where your hearing threshold is rather elevated. I doubt you'd hear -60 db 7th harmonic.

 

[AnalogSteph]

I had a few test files in a thread on noise floors once. (I don't think those files are up for download currently). I put noise into a clean file at various levels and asked everyone to say when it was inaudible. I asked they start with enough noise they heard it clearly. This while listening to music at their normal levels. Most results were -75 to -80 db for most who responded if my memory isn't shot.

At what sort of average music levels would this have been? -10, -14, -20 dBFS? Or would these -75 to -80 dB already have been the delta between signal and noise? Seems a bit high to me then.

 

[Snarfie]

My impression is more can we trust/rely on our knowledge/experience how an instrument or a voice must sound than our ears (in the first place) rather than blind test listing to differences between different music files with minimal differences.
The last year is more more less a revelation for me regarding how something can or must sound because of a combination of installing acoustic panels and making use of room correction software.

I'm 59 and are listing with passion to music for more than 50 years. Been to many live performances like Steely Dan, Barry White, Toto, Marcus Miller, Miles Davis, Chaka Khan at the Blue Note (NYC) Clubs like Paradise Garage, Studio 54 and so on. So a bit of experience i can rely on (i hope).
My latest measurements here under.

It shows that there is resonance some where between 300 and 8.000 Hz (Grey line uncorrected frequency response) looks like an range that influence voices. I can tell you it did massively such that mid and lower frequencies diminished greatly. The white line is the found/used room correction which eliminate al above describe resonance. Result for the first time Barry Whit is not a Soprano an does not end the S tone with a Sssshhhh that sound almost like snare drum. Basically the whole sound experience is way more balanced not parse more spectacular. But the interaction between the band members listening at home at my music gear is greatly improved. An improvement i did not experience in 50 years.

 

[Blumlein 88]

At what sort of average music levels would this have been? -10, -14, -20 dBFS? Or would these -75 to -80 dB already have been the delta between signal and noise? Seems a bit high to me then.

Well my memory wasn't perfect, but you can read about the files in the thread.

https://www.audiosciencereview.com/...hat-level-is-noise-heard-in-your-system.1013/
The levels were dbFS.

 

[graz_lag]

My impression is more can we trust/rely on our knowledge/experience how an instrument or a voice must sound than our ears (in the first place)...

Yamaha declares that their electronics are tuned on the tone range of their pianos ...

 

[AnalogSteph]

Well my memory wasn't perfect, but you can read about the files in the thread.

https://www.audiosciencereview.com/...hat-level-is-noise-heard-in-your-system.1013/
The levels were dbFS.

Tried this for myself now. I picked a track at -13/14 dBFS average, -0.8 dB peak, relatively undynamic. Added white noise at -24, -34, -44, -54, -59, -64, .. -84 dBFS. Everything down to -59 dBFS was easily audible, beyond that it gets harder and harder. I can still just about pick up -69 on the fadeout, but that's about it. I should try again with -74 once the party next door is over, but right now it looks like this isn't happening at my normal levels without sticking my ear to the tweeter. So the old rule of thumb of 70 dB of required dynamic range actually seems to be pretty much spot on for me.

Maybe I'll try some pink noise or EQing my white noise like tape noise next, that could be interesting. If I want the effect of 3180/120µs, I need no more than a 6 dB highpass at 50 Hz and a 6 dB lowpass at 1326 Hz, is that correct?