Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: What is the real _lowest_ audible frequency? (Read 34306 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

What is the real _lowest_ audible frequency?

Reply #50 –
Quite honestly I've never been a fan of in-ears.

For this test they were perfect though. If you have in-ears with clean and good bass, then you should be able to reproduce that below 20 Hz the sensation of a tone fades. This only works if your headphones can put out high SPL without any other noises. If you hear mechanical noise then you probably hit the limits of the drivers. If you hear clear tones even well below 20 Hz then the drivers probably produce large amounts of harmonic distortion.

So yes, I think using 20 Hz as lower hearing limit is not a bad choice. Given enough sound pressure we can also perceive much lower frequencies, but that's not heard as tones anymore.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #51 –
Quote from: xnor on
Might be useful:



Here is an older reference. http://scitation.aip.org/content/asa/journ....1121/1.1914605

Consistent with the above: roll-off is less steep below 20. Somewhere around the 100 dB mark, you can hear 10 Hz (not merely feel it in your bowels).


Edit: How do I scale images?

What is the real _lowest_ audible frequency?

Reply #52 –
Quote
If the frequency is gradually lowered from 20 Hz, the tonal sensation disappears, the sound becomes discontinuous in character and it changes into a sensation of pressure at the eardrums. At even lower frequencies it turns into a sensation of discontinuous, separate puffs, and it is possible to follow and count the single cycles of the tone.

"I hear it when I see it."

Re: What is the real _lowest_ audible frequency?

Reply #53 –
Quote from: Porcus on
Here is an older reference.

A 1967 paper from the same first author, claims that 1.5 Hz could be audible even through earphones. From that and other papers,
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/335014/RCE-14_for_web_with_security.pdf claims a population-median hearing threshold of 107 dB at 4 Hz.

Re: What is the real _lowest_ audible frequency?

Reply #54 –
Which matches the very first graph I've posted, and neither are perceived as tones.
"I hear it when I see it."

Re: What is the real _lowest_ audible frequency?

Reply #55 –
Quote from: xnor on
Which matches the very first graph I've posted, and neither are perceived as tones.

Badly formed questions tend to lead to unsatisfactory answers.  A better question might be "what is the lowest frequency the human ear can hear as a musical tone?" but even this is not easily answered because the answer depends on the loudness of the signal.  We can hear lower tones at high volumes than at low volumes.

For practical purposes "20hz" is good a good enough answer since almost no one can afford a system that will go that low anyway.

Ed Seedhouse
VA7SDH

Re: What is the real _lowest_ audible frequency?

Reply #56 –
Quote from: xnor on
Which matches the very first graph I've posted, and neither are perceived as tones.

Matches, and Yeowart / Yeowart et al. are not referenced in the graphs. So it seems to be quite clear from even more sources that the human ear can pick up much lower frequencies than the 20 Hz.

Re: What is the real _lowest_ audible frequency?

Reply #57 –
Quote from: Ed Seedhouse on
Badly formed questions tend to lead to unsatisfactory answers.  A better question might be "what is the lowest frequency the human ear can hear as a musical tone?" but even this is not easily answered because the answer depends on the loudness of the signal.  We can hear lower tones at high volumes than at low volumes.

We can hear higher tones at high volumes than at low volumes as well, but the upper frequency is at least not octaves off reality. The 20 kHz limit was formed by extrapolating the hearing and the pain threshold, and guessing where the lines would cross. Correct or not, it has an operational rationale.

Quote from: Ed Seedhouse on
For practical purposes "20hz" is good a good enough answer since almost no one can afford a system that will go that low anyway.

... which seems to be why the "20" showed up in the first place - operational in some sense, but related to equipment much more than to the human ear. Yes, badly formed questions tend to lead to answers like that.

And most of us can afford equipment that can reproduce the sub-20 Hz range. I used these to hit 11 Hz: http://www.areadvd.de/hardware/2008/akg_k321.shtml (and they cost me about half of the quoted price).

Re: What is the real _lowest_ audible frequency?

Reply #58 –
Quote from: Porcus on
So it seems to be quite clear from even more sources that the human ear can pick up much lower frequencies than the 20 Hz.
I will try a last time.

Yes, the ear drum is pressure sensitive. Yes, it will even pick up a 1 Hz change in air pressure, given it is high enough - your whole body can. You can "perceive" it.
But it will not sound like a tone.


PS: If an in-ear reproduces 10 Hz at a significant level then this means lots of excursion for the eardrum (even during normal music playback), triggering the stapedius reflex, lowering fidelity and causing you turn up the music even louder. So bad sound quality coupled with potential hearing loss.
The only way I'd ever gonna try an in-ear again or spend any money on it is if it came with something like the diaphonic ear lense, where an additional membrane acts as a high pass filter to pressure on the eardrum.
"I hear it when I see it."

Re: What is the real _lowest_ audible frequency?

Reply #59 –
Quote from: xnor on
Quote from: Porcus on
So it seems to be quite clear from even more sources that the human ear can pick up much lower frequencies than the 20 Hz.
I will try a last time.

Yes, the ear drum is pressure sensitive. Yes, it will even pick up a 1 Hz change in air pressure, given it is high enough - your whole body can. You can "perceive" it.
But it will not sound like a tone.


PS: If an in-ear reproduces 10 Hz at a significant level then this means lots of excursion for the eardrum (even during normal music playback), triggering the stapedius reflex, lowering fidelity and causing you turn up the music even louder. So bad sound quality coupled with potential hearing loss.
The only way I'd ever gonna try an in-ear again or spend any money on it is if it came with something like the diaphonic ear lense, where an additional membrane acts as a high pass filter to pressure on the eardrum.

Thanks!  That's really cool good to know info. 
Be a false negative of yourself!

Re: What is the real _lowest_ audible frequency?

Reply #60 –
What would happen if I moved my ears up and down? Say that I am 2 meters tall. Like riding a roller coaster along a perfectly sinoidal course at +/- 1 meter deviation at some periodicity. Let's ignore possible other physical effects from the acceleration.

%https://en.wikipedia.org/wiki/Barometric_formula
%Equation#2
g0 = 9.80665;
M = 0.0289644;
h = 2/2;%pertubations about the mean
hb = 11000;
R = 8.31432;
Tb = 20 + 273.15;
pres_mod = exp(-g0*M*(h-hb)/(R*Tb));
p0 = 20e-6;
SPL = 20*log10(pres_mod/p0);
SPL =

  105.1130

Re: What is the real _lowest_ audible frequency?

Reply #61 –
Quote from: xnor on
If the frequency is gradually lowered from 20 Hz, the tonal sensation disappears, the sound becomes discontinuous in character and it changes into a sensation of pressure at the eardrums. At even lower frequencies it turns into a sensation of discontinuous, separate puffs, and it is possible to follow and count the single cycles of the tone.
You have mentioned this a few times. Characterizing a perception as having a "tonal quality" or not, or as being musical or not, sounds very subjective. Do you have any references on how below 20Hz sound is perceived? I thinks "puffs, ...that you can count" is very, very low frequency, and I don't imagine perception from responses of the ear elicit the description "puffs". That sounds more like a tactile perception.
I don't mean to be argumentative; I'm curious about this.
 

Re: What is the real _lowest_ audible frequency?

Reply #62 –
Quote from: bobbaker on
Characterizing a perception as having a "tonal quality" or not, or as being musical or not, sounds very subjective.

In this particular case, the difference between a musical sound and a non-musical sound is IME pretty clear cut.

I think there is a problem where valid terminology relating to real events  has been hijacked by placbophiles so many times that people doubt its validity.

I've done listening tests based on large systems with relatively clean response into the 5 and 10 Hz range.  Systems with performance like this have been around since no later than the late 1970s. They are pretty common these days.

Quote
Do you have any references on how below 20Hz sound is perceived? I thinks "puffs, ...that you can count" is very, very low frequency, and I don't imagine perception from responses of the ear elicit the description "puffs". That sounds more like a tactile perception.

https://en.wikipedia.org/wiki/Infrasound

for example.