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Topic: What is the real _lowest_ audible frequency? (Read 34073 times) previous topic - next topic
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What is the real _lowest_ audible frequency?

Reply #25 –
Quote from: xnor on
Honestly, "0.189Hz" .. that sounds like a load of BS.

I don't think it is physically possible for ~2.5cm vocal cords to produce any significant SPL that low.

Lower generally accepted vocal folds range is what, 80 Hz?

If I inhale and exhale once every 5.29 seconds am I emitting 0.189 Hz?

What is the real _lowest_ audible frequency?

Reply #26 –
Quote from: pdq on
If I inhale and exhale once every 5.29 seconds am I emitting 0.189 Hz?

Yes.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #27 –
The detection of infrasonic waves is used to enforce the Comprehensive Nuclear Test-Ban Treaty as well as for basic research. A Google search for "infrasonic monitoring" will bring up many useful hits. The Wikipedia entry for Infrasound could do with some work, for example it uses the Graham Holliman speaker as an example of an infrasonic generator.
Regards,
   Don Hills
"People hear what they see." - Doris Day

What is the real _lowest_ audible frequency?

Reply #28 –
Quote from: mzil on
Since humans don't perceive .187 Hz (at least not as "sound"), and no microphone can record it, are we asking the elephants what frequency he is emitting?



Well come to that we can "perceive" a D.C. signal in air.  It's known as "wind".
Ed Seedhouse
VA7SDH

What is the real _lowest_ audible frequency?

Reply #29 –
Quote from: Ed Seedhouse on
Well come to that we can "perceive" a D.C. signal in air.  It's known as "wind".


I think a better example would be the atmospheric pressure which you don't perceive as long as it is in a "normal" range.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #30 –
Quote from: Cubist Castle on
Quote from: mzil on
Since humans don't perceive .187 Hz (at least not as "sound"), and no microphone can record it, are we asking the elephants what frequency he is emitting?
It's certainly feasible to design a microphone that can record this - accurate reproduction would be a bit more challenging though!
Danish company Brüel & Kjaer has a large collection of measurement microphones:
4193 - ½-inch infrasound microphone, 0.07 Hz to 20 kHz, 200V polarization

What is the real _lowest_ audible frequency?

Reply #31 –
Here is an example with (arguably) real music. "Space" from the album "Anthropomorphic" of The Mount Fuji Doomjazz Corporation (just a different moniker for The Kilimanjaro Darkjazz ensemble).

http://www.youtube.com/watch?v=6d6qtfjg_10 .  Beware the volume knob. 

Around the 3 minutes mark there is a tone around 30 Hz that around 3:18 descends to 24.  Then it is the part where I really have to turn up to hear it: to about 20 Hz until the 5 minutes mark. At 5:03 it does a quick bounce (very distinct in my living room) up and back down before it sweeps up. 

Frequencies eyeballed off foo_musical_spectrum .

What is the real _lowest_ audible frequency?

Reply #32 –
Quote from: pdq on
Quote from: xnor on
Honestly, "0.189Hz" .. that sounds like a load of BS.

I don't think it is physically possible for ~2.5cm vocal cords to produce any significant SPL that low.

Lower generally accepted vocal folds range is what, 80 Hz?

If I inhale and exhale once every 5.29 seconds am I emitting 0.189 Hz?

If you inhale and exhale once every 5.29 seconds, you are Lee Marvin singing 'Wandering Star'.

What is the real _lowest_ audible frequency?

Reply #33 –
Regarding Tim Storms' sub-1Hz:

He got his vocal range measured to nearly ten octaves from 0.8 to 807 Hz. Now if you are able to do something that remotely resembles a sweep, or even progress down or up without significant discontinuities in how you put your chords at work [edit: he must definitely have been switching to falsetto somewhere way into the audible range though, but nobody would question a 'vocal range' for doing that ... except when musical quality is a criterion, which it is not in this case], then there is no way to put a knife down and claiming these are notes, those are not. It would have been most clarifying if they had put up the recording.

Back around y2k he "merely" hit 8 Hz that way: http://www.bagend.com/rescue.htm . But a sweep down to 8 Hz is still the range that internet idiots claim not to exist because they have somewhere read a "20" figure ...

Storms is not the only one to have broken into fractional hertzes - the .2 was performed only to reclaim the record from Roger Menees who beat his .8 by an octeave:
http://bransontrilakesnews.com/news_free/a...1a4bcf887a.html


Here's how he's actually singing. Live clip uploaded 2009: http://www.youtube.com/watch?v=tJcjCztvn70 . Studio version: http://www.youtube.com/watch?v=C-v7xn9QarU

What is the real _lowest_ audible frequency?

Reply #34 –
In the recording you linked he hits ~30 Hz, which is impressive. If it were a clean tone you could probably still hear this even if he didn't have any additional amplification (it takes >60 dB SPL according to #2).

I'd love to see a recording of their claimed sub-20 Hz "singing". So far all we've got are sensational news articles/anecdotes, right?

We still don't know what they measured in those anechoic chambers. I can put any recording through a spectrum analyzer and show you moving bars below 10 Hz. So what?
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #35 –
,
Quote from: Porcus on
Bass-ically, I have the following questions:

1) How can we define the lower boundary frequency in a sensible way?


Good question. Down thread someone, apparently with humorous intent, asks whether a puff of air every 5 seconds constitutes a 0.2 Hz signal.

Doesn't make a lot of sense to me. I know that a FFT will find a signal buried in the series of air puffs @ 0.2Hz, but its not what I think of as bass.

A real world example of a really low intense LF signal might be air buffeting in a fast-moving car with some of the windows open. Strong (> 110 dB SPL) signals in the 1 Hz range might be found with the right equpment.

Is it bass in a real sense?

In a musical sense?

In a sound effects sense?

Do you hear it or do you feel it by non-aural means (e.g. ears popping or guts rattling).

What is the real _lowest_ audible frequency?

Reply #36 –
"Vocal fry" hit the news in 2011 as a speech pattern ( http://www.today.com/video/today/45681253 ) but as a singing technique, it does somewhat blur the distinction between "notes" and "repeated pulses": http://en.wikipedia.org/wiki/Vocal_fry_register
Like in this clip: http://www.youtube.com/watch?v=0e_yDunvnsw .

And ... if anyone feels like checking what really is in this one, and then DSP'ing up a few octaves? http://www.youtube.com/watch?v=UJwB0PK5yOk

This seems to have quite a bit of background noise: http://edition.cnn.com/video/data/2.0/vide...-voice.cnn.html

I wouldn't bet that the notes annotated to this video are accurate, but http://www.youtube.com/watch?v=WWb7_sCNGus has some quite impressive stuff at the end.


What is the real _lowest_ audible frequency?

Reply #37 –
Mostly >30 Hz with some low frequency rumbling noises.

The main difference between this and "normal" recordings is that really low frequency noises are not filtered out. Especially vocals are usually aggressively high-pass filtered in modern recordings.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #38 –
In some audio and technical debate circles (where people themselves argue and debate in circles) it's sometimes even accepted that people can't hear under 30Hz. The ABX testers and empirical crowd insist that the detection of sounds below that region is the sole result of the body responding to tactile bass. I don't know, I'm not completely convinced.

The distortion of Senn and Beyerdynamic headphones is stated as less than 0.1%, or about -60dB. That is at a higher playback amplitude than I would ever listen at, so distortion should be lower at more comfortable levels. The playback gear is flat within 1dB across the board. If we were top play test tones at 55-65dB, the distortion should be below the lowest sounds most of us could hear. Since headphones stimulate the eardrums and not the body, we can more or less assume that it is isolated.

If people can still hear very low frequencies, this may call those claims into question.

What is the real _lowest_ audible frequency?

Reply #39 –
Quote from: NigelinNY on
... The distortion of Senn and Beyerdynamic headphones is stated as less than 0.1%, or about -60dB. ...


But at what frequency? It's common for speakers (and headphones) to generate more distortion at the lowest end of their response range.
Regards,
   Don Hills
"People hear what they see." - Doris Day

What is the real _lowest_ audible frequency?

Reply #40 –
Quote from: NigelinNY on
In some audio and technical debate circles (where people themselves argue and debate in circles) it's sometimes even accepted that people can't hear under 30Hz. The ABX testers and empirical crowd insist that the detection of sounds below that region is the sole result of the body responding to tactile bass. I don't know, I'm not completely convinced.


Playing a 20Hz test tone into my IEMs would seem to disagree with that. I can definitely hear it, my body isn't being vibrated at all. Unless for some reason I'm hearing harmonics or something.

What is the real _lowest_ audible frequency?

Reply #41 –
Tried my cheapest earbuds (AKG K321 at around $40)
I hear both 15, 12 and 11 Hz, but not 10 Hz. 10.5 Hz is ... I'd say "not really". Sample: used SoX to reverse and speed down Rotareng's file from page 1 - reverse to get rid of an initial 'click' in the headphone outlet.
I do hear 'vocal fry'-type artifacts; e.g. on 15 Hz I can kinda 'count to fifteen'. Is that an indication of distortion in the form of a "higher frequency burst" every fifteenth of a second? Since distortion could be highly nonlinear, there could be much less of it at 10.5 than at 11, but I kinda doubt that distortion alone explains this - subjective volume diminishes without any pronounced booms.

Subjective frequency linearity (I mean, not listening critically for nonlinearities, but rather on the 'would this be drowned?' basis) indicated they do reach 25 quite flat, and that 20 could maybe be useful, the drop was surprisingly small.

Then for music, over to the Mount Fuji Doomjazz Corporation piece I linked to above, and the 20 Hz tone nearly disappears (it is audible, it isn't worthless, but I could have missed it if my first encounter with the piece was casual listening while busy working ... or reading hydrogenaudio :-) ). In my living room I sense slightly more of it in the music despite the single sine having more of a (subjective) drop, and I see three different (but not mutually exclusive) explanations: (I) some distortion in the earbuds (being more masked in music, hence subjectively lowering the volume) (II) the physical sound pressure from the loudspeakers (subjectively enhancing the volume) and (III) I have no way to match volume, and I likely turn up the buds more as they do not shake the house.

What is the real _lowest_ audible frequency?

Reply #42 –
I don't think there's some frequency where you can say: below that you just feel something, above that you hear a tone. But the census about that and start of useful frequency range is thought to be ~20 Hz.

You may have special requirements where you need to go lower, but with mainstream music I doubt you'd miss much even with a higher cutoff frequency.
Fun fact: apple ear pods roll off at 100 Hz, ear buds at roughly 250 Hz. But with in-ears we can now achieve flat bass down to below 20 Hz.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #43 –
Hi probedb and splice, thanks for the replies.

The particular site which held all the measurements vanished within the last 2 years. It had a range of test results for many popular and pro headphones. I do recall the distortion in the lower spectrum was still quite controlled compared to others, with the stated distortion measurement being near 500Hz. I'll see if I can gather any information from some other sources.

What is the real _lowest_ audible frequency?

Reply #44 –
I pulled out my old IEMs that, according to IF, do 100 dB SPL at 20 Hz at 0.1% THD+N, with flat FR down to 10 Hz.
Below roughly 19 Hz it doesn't feel like a tone anymore. At even lower frequencies it feels more and more like fluctuating pressure changes at the eardrum only - very annoying.

(Now I know why I don't use IEMs again. The seal makes me hear even my own hearbeat, the pressure buildup fatigues my ears, microphonics from the cable ... an overall horrible experience  )
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #45 –
Quote from: xnor on
But the census about that and start of useful frequency range is thought to be ~20 Hz.


Hence the "real" in the subject line.


Quote from: xnor on
(Now I know why I don't use IEMs again. The seal makes me hear even my own hearbeat, the pressure buildup fatigues my ears, microphonics from the cable ... an overall horrible experience  )


I think you were outdone by whoever once wrote the line "so quiet that I can hear myself thinking ... and that is uncomfortable indeed" 

What is the real _lowest_ audible frequency?

Reply #46 –
Quote
I pulled out my old IEMs that, according to IF, do 100 dB SPL at 20 Hz at 0.1% THD+N, with flat FR down to 10 Hz.
Below roughly 19 Hz it doesn't feel like a tone anymore. At even lower frequencies it feels more and more like fluctuating pressure changes at the eardrum only - very annoying.

(Now I know why I don't use IEMs again. The seal makes me hear even my own hearbeat, the pressure buildup fatigues my ears, microphonics from the cable ... an overall horrible experience)


That seems to be quite excellent...the "heartbeat function" and pressure chamber experience notwithstanding. I get that many like the in-ear types a great deal. I guess there are as many different designs are their are preferences. If I could, I'd consider them.

The Sennheiser is printed as .1% THD at 100dB. The Beyers have higher printed distortion, but in tests was much better. I also prefer them for low frequencies in listening because the bass doesn't draw negative attention. Fun.

What is the real _lowest_ audible frequency?

Reply #47 –
Well the only thing I like with those Nocs (iirc) in-ears of mine is isolation. IF measured broadband isolation of ~35 dB. Fancy earplugs that can also produce music if you will. 

I'm afraid manufacturer specs won't really tell you anything. They usually measure a 1 kHz tone, where distortion is usually very low even at high SPL.
Dynamic headphones often show increasing THD below roughly 200 Hz. You can only achieve low THD with such headphones if you have extreme seal (similar to in-ears), or huge drivers plus some seal. In ever other case the driver will approach excursion limits at low frequencies and easily produce 10% THD at high SPL.
"I hear it when I see it."

What is the real _lowest_ audible frequency?

Reply #48 –
Quote from: xnor on
(Now I know why I don't use IEMs again. The seal makes me hear even my own hearbeat, the pressure buildup fatigues my ears, microphonics from the cable ... an overall horrible experience  )


You just haven't had the right ones then. I've been wearing them for years and never have any of the issues you speak of and they seal well.

What is the real _lowest_ audible frequency?

Reply #49 –
The cables on my Etymotic ER-4s, are notoriously noisy. I mean mechanical noise. Best used in the office. The cheap AKGs are in fact way better.