Human hearing frequencies

[bass_ferret]

From an internet article totally unrelated to bass playing, but does crop up from time to time.

[quote]By comparison, the human voice is general in the range of 80 to 1,100 Hz, and good human hearing runs from around 20 to 20,000 Hz.[/quote]

[Mr. Foxen]

Bass players hearing from 20hz to 800hz. Voices telling them to stop buying gear 2000hz.

[Prosebass]

[quote name='bass_ferret' post='380884' date='Jan 15 2009, 12:25 AM']From an internet article totally unrelated to bass playing, but does crop up from time to time.[/quote]

You been wikiing ? oo er mrs.....

[BigAlonBass]

Can open - worms everywhere.

[bremen]

[quote name='BigAlonBass' post='380978' date='Jan 15 2009, 08:54 AM']Can open - worms everywhere. [/quote]

ok here we go:

'By comparison, the human voice is general in the range of 80 to 1,100 Hz, '

Those numbers refer to the fundamentals of the notes that humans can sing. Sounds like 's' and 't' have components well into the tens of kHz. Take a recording of human speech and cut out the frequencies above 1100Hz and it'll be pretty much unintelligible.

[Balcro]

[quote name='bass_ferret' post='380884' date='Jan 15 2009, 12:25 AM']From an internet article totally unrelated to bass playing, but does crop up from time to time.

By comparison, the human voice is general in the range of 80 to 1,100 Hz, and good human hearing runs from around 20 to 20,000 Hz.[/quote]


That's the very best it's ever likely to be. By the time you're 20 you've probably lost the top 2KHz. By the time you're 50, the top end is probably down to 14KHz. That's at the level of audibility, so it doesn't mean you will hear 14k as clearly as 2K.
On top of that you start to get variations between ears, so it would not be unusual to get 4 - 6dB difference in sensitivity between ears, even in your 30's.

...and it gets better. Long term use of some medicines may have an effect on hearing. Good old fashioned quinine, which used to be the principle anti-malarial treatment 100 years ago, is an established hearing wrecker.

Balcro.

[escholl]

[quote name='bremen' post='381237' date='Jan 15 2009, 01:17 PM']ok here we go:

'By comparison, the human voice is general in the range of 80 to 1,100 Hz, '

Those numbers refer to the fundamentals of the notes that humans can sing. Sounds like 's' and 't' have components well into the tens of kHz. Take a recording of human speech and cut out the frequencies above 1100Hz and it'll be pretty much unintelligible.[/quote]


Also to add that part of human speech that makes it intelligible is around 2-4kHz, regardless of fundamental. Hence why this range is sometimes boosted if a vocal track is having difficulty standing out in a mix (instead of boosting the overall track volume) and why some older phone systems can be difficult to understand people over (as they cut frequencies above around 3k to minimize propagation distortion, or whatever it's called)

[charic]

Who knows why we percieve 1-2khz as being loudest then?

Latest theory I heard in acoustics (back in uni) is it is approximately the same frequency range as a baby crying. Course were still not sure how we percieve pitch so all of this is irrelevant lol

[silverfoxnik]

[quote name='charic' post='381640' date='Jan 15 2009, 07:25 PM']Who knows why we percieve 1-2khz as being loudest then?

Latest theory I heard in acoustics (back in uni) is it is approximately the same frequency range as a baby crying. Course were still not sure how we percieve pitch so all of this is irrelevant lol[/quote]

That's right.. A babies vocal range is designed by nature to be at the most attention grabbing pitch it can be, purely for survival reasons..

[bremen]

[quote name='silverfoxnik' post='381648' date='Jan 15 2009, 07:36 PM']That's right.. A babies vocal range is designed by nature to be at the most attention grabbing pitch it can be, purely for survival reasons..[/quote]

So did the 1kHz hearing peak exist before babies evolved to yell loudest at that frequency, or did human hearing evolve to be most sensitive to the frequency of crying babies?

Next week: chickens and eggs

[Leowasright]

I would like to deaf in the frequency range my wife talks in..........

[Protium]

[quote name='bremen' post='381746' date='Jan 15 2009, 09:23 PM']Next week: chickens and eggs [/quote]

Fried and fried.

[madzombieguy]

Generally, our threshold of hearing lies within the 20Hz to 20kHz range. A series of tests were conducted to determine our sensitivity to different frequencies, which in turn, effect our perception of where the sound may be located. “Out of these tests, it was found that the human ear is most sensitive to frequency's between 2kHz – 4kHz” (Baert, 1995). The average person is said not to hear below 2kHz, so sounds around this level are known to seem quiet and often we feel that the softness of a sound psychologically means that it is further away from us. However, as Chowning (1999) states; “before speculating about the answer, we should consider the effect of distance on intensity.”

To experiment, we can position a subject at a distance of roughly 1 metre from the listener and position another subject at a distance of 30 metres (Figure 4.0). The closer subject would speak softly as he/she would be closest and the further away subject would obviously have to speak loudly. This is made obvious by the fact that sound disperses through distance. This experiment reveals more than one single dimension to our perception of loudness. It is known that sound disperses over distance, however, as the pressure in the sound wave moves away from the subject, the actual surface area gains in size. As the surface area in a spherical context would increase alongside the square of its radius, its intensity makes up for this increase by decreasing in accordance with time and distance travelled using the inverse square law (1/d², seen in Fig 5.1). As the distance we are using is set at 30 metres then the intensity must decrease at 1/30² or 1/900 of the intensity of the sound provided by the subject at just 1 metre (Chowning, 1999).
As this suggests, the distance we perceive alongside our actual auditory perspective means that the amplitude in relation to both of the subjects at different distances could be identical. To work this out, lets just assume that the sound being produced by the subject at 1 metre is of an intensity 1/144 of that of the further intensity. It seems obvious that the closer intensity is much greater and perceived as louder. This is not always the case, as the listener would most often state that the softly spoken person at 1 metre sounded more quiet than the shouting person at 30 metres, despite the softly spoken person having a tone of much greater intensity. We can work this out by calculating the intensity so that I (Intensity from source, at culminating point) can be found by following the equation S ÷ 4πr² where: S = the source strength, and 4πr² = the spherical area.

Scientists often just refer to the majority average which is depicted by the famous Fletcher-Munson curves.
Fletcher-Munson graph:
.
These curves on the graph represent equal loudness contours for sounds created using sine waves. A range varying from below 20Hz (the average understanding of our lowest noticeable level of hearing) up to more than 10kHz is displayed. The vertical axis represents the intensity (sound pressure level) in dB, where as the horizontal axis displays the range of frequencies. The curves display a great deal of variation which help us to understand how sensitive our ears are to different frequencies. For example, “in order for a soft sound at 50Hz to sound as loud as one at 2000Hz, the 50Hz sound has to be about 50dB more intense than the 2000Hz sound” (Matthews, 1999). This means that the human ear is more sensitive to sounds at 2Khz than at 50Hz.

With these curves, tests carried out to simulate the results shown are usually using tones rather than other sounds. The main reason is that everyday sounds have a variety of natural harmonics in them which can often cloud our perspective, especially at higher pitch's where the loudness is often added to by the contribution of these harmonics. We often perceive everyday sounds as particularly loud because dB is logarithmic, therefore, the sound build up is quite intense.

We also have to think about aspects such as cultural conditioning.
By the term ‘cultural conditioning’, I am referring to the way in which the human body and more importantly here - the human ear, works. When we are brought into the world or even just before it, we are not familiar with our surroundings and it takes time for us to adjust and become comfortable in remembering where we are and what people look like. The human ear allows us to become comfortable first with sounds.
For example, it is said that a baby can always tell who it’s mother is, by sound alone. It has also been known, though not yet 100% proven, that a baby can remember and associate sounds it has heard coming from someone, whilst still within the womb.

“Audiotapes were played to 60 pregnant women to see how the developing child responded to the voice of either its mother or a female stranger.
The scientists found the baby's heart-rate speeded up when it heard its mother but slowed down in response to a stranger's voice” (BBC News, 2003)

Edited January 15, 2009 by madzombieguy

[pete.young]

[quote name='escholl' post='381415' date='Jan 15 2009, 03:49 PM']Also to add that part of human speech that makes it intelligible is around 2-4kHz, regardless of fundamental. Hence why this range is sometimes boosted if a vocal track is having difficulty standing out in a mix[/quote]

When I studied acoustics at university, I was taught that hearing loss induced by exposure to noise always peaks at 4 KHz, at the top end of the speech range. This is another reason why lots of music has a spurious boost at 4 KHz (Paul Adams at Fellside Records once told me that it was SOP in many mastering shops) and why when you get old you can stand in a pub, hear the background noise perfectly but struggle to pick out the conversation of the bloke sitting across the table from you.

[alexclaber]

Something that needs to be considered is that we don't not merely hearing noise, we're hearing vibrations and then there is a huge amount of processing going on for the brain to disseminate that information into musical sense. I mentioned this in another thread but "This Is Your Brain On Music"is really enlightening on this kind of stuff.

So although a young human might hear 20-20,000 just fine, how well they turn that sensitivity to frequencies into hearing the components of music is dependant on what their brain does with that data.

A good example is to just think back to when you started playing bass and how much harder you found it to hear the basslines in recordings compared to now after years of experience. Have your ears got better or has your hearing got better?

Alex

[silverfoxnik]

[quote name='alexclaber' post='381912' date='Jan 15 2009, 11:39 PM']A good example is to just think back to when you started playing bass and how much harder you found it to hear the basslines in recordings compared to now after years of experience. Have your ears got better or has your hearing got better?

Alex[/quote]
Ears, definitely due to more experience..

[TimR]

Depends on what you mean by ears and hearing. My listening has got better.

Your hearing has got worse, you ears have got tired, but your brain has learned how to filter out the unwanted rubbish like guitars and drums.

I used to live next to a railway, the trains kept me awake for a few days. I got used to them. Then I moved and I couldn't sleep because it was too quiet.

Anyway... As you were. I'm not sure where I'm going with that, maybe the brain trains itself, I should chuck out the DS.

[Bay Splayer]

i said, [b][color="#000000"]IT`S JUST GONE TEN TO TWELVE[/color][/b]

[drumbloke]

[quote name='TimR' post='381942' date='Jan 16 2009, 12:25 AM']Depends on what you mean by ears and hearing. My listening has got better.

Your hearing has got worse, you ears have got tired, but your brain has learned how to filter out the unwanted[color="#FF0000"] rubbish like guitars and drums.[/color]
I used to live next to a railway, the trains kept me awake for a few days. I got used to them. Then I moved and I couldn't sleep because it was too quiet.

Anyway... As you were. I'm not sure where I'm going with that, maybe the brain trains itself, I should chuck out the DS.[/quote]

OI ! a bit of mutual respect eh!! Please!

What about harmonics on the fundamental frequency then?...you may not hear 14khz, but you would hear the lower register harmonics of 14khz, so your brain would know that 14khz has sounded, therefore your brain would know that was 14khz, thus you 'heard' 14khz....

I'm talking absolute bollox aren't I?

Next Week...Lose weight with 'Lager' flavoured Celery.

Coat.. Hat... i've left

[Rich]

[quote name='Leowasright' post='381756' date='Jan 15 2009, 09:32 PM']I would like to deaf in the frequency range my wife talks in..........[/quote]
coffee -> screen

Invent a machine that does this, and you'll be a very rich man.

[clauster]

[quote name='alexclaber']A good example is to just think back to when you started playing bass and how much harder you found it to hear the basslines in recordings compared to now after years of experience. Have your ears got better or has your hearing got better?[/quote]

Or to put in terms a psychologist would use - has your ability to sense (ie turn pressure into neural impulse) or perceive (ie interpret those neural impulses) got better. For most of us it'll be our perception that has improved.

Very rarely, without surgery or artificial aids does sensation improve after young adulthood, most senses slowly deteriorate after this point. Perception on the other hand continues to improve with experience.

[quote]So did the 1kHz hearing peak exist before babies evolved to yell loudest at that frequency, or did human hearing evolve to be most sensitive to the frequency of crying babies?[/quote]

It's probably the yelling that evolved to be at that frequency. Babies that yell significantly higher or lower have less chance of being heard and would be less likely to live through infancy and so wouldn't pass on the "abnormal yelling frequency" genes and so through natural selection the trait dies out.


At long last a degree in Psychology has been of practical application (and that includes 10 years working in Mental Health )

[alexclaber]

[quote name='drumbloke' post='382223' date='Jan 16 2009, 12:08 PM']What about harmonics on the fundamental frequency then?...you may not hear 14khz, but you would hear the lower register harmonics of 14khz, so your brain would know that 14khz has sounded, therefore your brain would know that was 14khz, thus you 'heard' 14khz...[/quote]

You're on the right track but in the wrong direction! Any musical note will have an overtone series above the fundamental but will not exhibit any harmonic energy below the fundamental (there may be percussive noises but these won't form part of the harmonic series and thus won't aid in defining the note).

When listening to orchestral music you will hear the piano, double basses and tuba play notes with fundamental frequencies well below 100Hz and even down to A0 (27.5Hz) and you will perceive the depth of these notes accurately. However because these instruments are all too small to produce appreciable fundamental content acoustically you will not actually be hearing the fundamental frequency at all, you will just be hearing the overtone series and your brain is doing the rest.

With electric bass guitars as you play progressively lower notes the fundamental content diminishes and more and more of the low frequency energy becomes focused on the 2nd harmonic (aka first overtone) and the 3rd harmonic. This is particularly notable with low B (and lower strings) even on longer scale lengths. Also the human ear is particularly poor at hearing these lower frequencies so the lower harmonic content is easily masked by the harmonic content just above that.

I noticed this in practice last week when I gave The Big One its first outing. For most of the rehearsal I mistakenly had the 50Hz filter engaged - between songs I was messing around seeing how much big open B notes made the speaker move and it didn't look like it was moving much at all. Then I realised I had that filter switched in. I switched it off and the speaker started moving a lot more but there was barely any change in the tone despite that resulting in another 10dB of output at 31Hz. On the other hand I noticed that The Big One had clearly more fatness in the bottom than The Compact with no EQ on either, which I believe it attributable it having on average about 4dB more sensitivity below 100Hz. In fact it even sounds as deep as my Acmes were, if not deeper, even though I know that they are only 6dB down by 31Hz whilst The Big One is over 13dB down at that frequency. But both cabs stay very strong down to below 60Hz which means you get full output of the 2nd harmonic on the lowest B string notes, whilst mainstream cabs are already quite a lot down by there.

I seem to have gone off on a tangent but the essence of it is this - you will hear how low a note is even when you're missing the lower harmonics. The tone of that note does not so much depend on the balance of the harmonic content but on the balance of the frequency content, so even if you're playing a 7-string with a low F# string as long as you get a good wodge of 50Hz action it'll sound fat and bassy and the way the overtones are stacked will make it sound a lot lower than four stringers low F# despite the vibrations hitting your eardrums being no lower in frequency.

Alex

[escholl]

[quote name='alexclaber' post='382387' date='Jan 16 2009, 01:56 PM']I seem to have gone off on a tangent but the essence of it is this - you will hear how low a note is even when you're missing the lower harmonics. The[b] tone[/b] of that note does not so much depend on the balance of the harmonic content but on the balance of the frequency content, so even if you're playing a 7-string with a low F# string as long as you get a good wodge of 50Hz action it'll sound fat and bassy and the way the overtones are stacked will make it sound a lot lower than four stringers low F# despite the vibrations hitting your eardrums being no lower in frequency.

Alex[/quote]

I'm guessing by "tone" you mean perceived pitch? Since the tone or timbre of a note is pretty much defined by the harmonic content, which is essentially the sum of the individual frequency and volume envelope components.

Also wanted to add that the ear perceives these low frequencies (or any frequencies) by, IIRC, the largest common denominator between pitches. So even if no frequencies below 100 Hz are generated, a note with a 50Hz fundamental will generate 100, 150, 200, 250, and 300 Hz, as an example, and the ear will "hear" a fundamental of 50Hz since that is the LCD.

25 Hz, on the other hand, will generate 100, 125, 150, 175, 200 Hz (and so on) so the LCD is 25 Hz, and the ear will "hear" 25 Hz; end result is that it will sound much lower.

So as Alex mentioned, getting a really strong second and third harmonic out of a cab is extremely important, as these will really "define" the fundamental pitch.

[alexclaber]

[quote name='escholl' post='382519' date='Jan 16 2009, 03:37 PM']I'm guessing by "tone" you mean perceived pitch? Since the tone or timbre of a note is pretty much defined by the harmonic content, which is essentially the sum of the individual frequency and volume envelope components.[/quote]

Actually I did mean the tone, not the perceived pitch. You're quite right that the harmonic content defines the timbre but what I was trying to make clear is that in the lowest register the harmonic content becomes quite strangely skewed due to the note wavelength vs instrument size and therefore those lowest notes on an ERB still sound like a bass guitar even though their harmonic balance is very different to an octave or two higher.

[quote name='escholl' post='382519' date='Jan 16 2009, 03:37 PM']Also wanted to add that the ear perceives these low frequencies (or any frequencies) by, IIRC, the largest common denominator between pitches. So even if no frequencies below 100 Hz are generated, a note with a 50Hz fundamental will generate 100, 150, 200, 250, and 300 Hz, as an example, and the ear will "hear" a fundamental of 50Hz since that is the LCD.

25 Hz, on the other hand, will generate 100, 125, 150, 175, 200 Hz (and so on) so the LCD is 25 Hz, and the ear will "hear" 25 Hz; end result is that it will sound much lower.

So as Alex mentioned, getting a really strong second and third harmonic out of a cab is extremely important, as these will really "define" the fundamental pitch.[/quote]

Indeed. What also helps with defining the pitch is having an instrument and amp that lets through the midrange frequencies with minimal distortion. As soon as you get harmonic distortion you get overtones being created from all the original overtones which can turn into real mud in the lowest registers. With many bass cabs the speakers have insufficient excursion to cleanly handle the lows on the lowest notes so you end up with increased harmonic distortion and thus mud. This is a particularly bad when you get distorted overtones of the 2nd, 3rd and 4th harmonic filling up the region around 150Hz - nightmare area for nasty boom. And the reason that many bassists caution against having too much bottom in your sound is not because the bottom itself is a problem (though they all think it is) but because trying to get your cab to reproduce that bottom causes overexcursion and thus an increase in harmonic distortion and thus mud and boom.

Alex

[escholl]

[quote name='alexclaber' post='382603' date='Jan 16 2009, 04:37 PM']Actually I did mean the tone, not the perceived pitch. You're quite right that the harmonic content defines the timbre but what I was trying to make clear is that in the lowest register the harmonic content becomes quite strangely skewed due to the note wavelength vs instrument size and therefore those lowest notes on an ERB still sound like a bass guitar even though their harmonic balance is very different to an octave or two higher.[/quote]

Sorry, you've confused me a bit on the last part there...what do you mean?


Also the second half of your post makes a lot of sense, I'd noticed that sort of effect before and thought it might be something like that, but I'd never put in all together in my head.