How low can we actually hear???

Discussion in 'Archived Threads 2001-2004' started by John Cain, Sep 16, 2001.

  1. John Cain

    John Cain Second Unit

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    As I was pondering Sub-Sonic filters I began to wonder, just how low can a human hear/feel frequencies???
    Can we hear or feel 15 Hz?? Can we hear or feel 10Hz ????
    Anyone???
    -- John
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  2. Chris Popovich

    Chris Popovich Stunt Coordinator

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    Humans average hearing is from 20-20,000Hz, however, at the extremes (at least the low extreme) it's also partially related to how loud it is -even with 'perfect' hearing a 20Hz tone would have to be louder than a 100Hz tone before you would notice it.
    I'm fairly young and try to take care of my ears, and in a quiet room I can hear down to about 16Hz, but it's faint. The 20Hz standby is pretty decent; I can easily hear that but it drops off pretty fast under 20...
    Of course, if it was an undistorted 120dB and nothing in the room was making noise, I'd suspect that lots of people could hear it. I may be completely wrong, but I heard someone say once that the threshold of hearing 3Hz is ~150db, which seems to indicate hearing is realted to how loud it is, the 20-20,000 being at some average level. Anyone else have something on this?
    As far as what you can feel, you can feel any frequency down to DC as long as the amplitude is high enough.
    Hope this helps,
    Chris
     
  3. John Cain

    John Cain Second Unit

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    Thanks Chris good points.
    I guess I'm thinking that these 16Hz organ notes are probably felt as much as heard, right??
    Take care,
    -- John
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  4. Chris Popovich

    Chris Popovich Stunt Coordinator

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    Yes, more felt than heard. Anything below about 30hz, for me anyway, tends to be more towards felt than heard. The 16hz organ note will be felt a lot more than heard, even by those with good ears.
    Take care,
    Chris
     
  5. Greg Cellini

    Greg Cellini Agent

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    Hi John,
    There is no actual "limit" with regard to the lowest frequency a human can "hear/feel". I'm sure anyone that's been through an earthquake will readily agree. The common misunderstanding is that humans perceive sound between 20 and 20,000 hertz. As most of us know, this is a gross generalization. What this actually means is that (most)humans perceive PITCH between those frequecies. Many humans can perceive acoustic energy, but rarely PITCH, beyond those boundaries. For instance, if I produced a sine wave below 20 hertz, most people would have difficulty indentifying it as a distinctive pitch: more like an undefinable "rumble".
    Hope this helps.
    Greg
     
  6. Rachael B

    Rachael B Producer

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    I agree with the concept that deep bass is felt more than heard. I think our perception sometimes is that we heard it, even if we realy didn't. I saw a deaf friend at a concert once. He said he could feel the bass. Best wishes!
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  7. Allan F

    Allan F Agent

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    As a Clinical Audiologist I felt that it was my duty to respond to this inquiry. Greg has a very good point. While 20 to 20 are the commonly accepted limits of human hearing, no actual limit exists. the fact is that the human cochlea (our primary organ of hearing) is characterized by different sensitivities at diffrerent frequencies. Hence the concept behind the dBA scale. We generally require much more energy in order to percieve a lower frequency than we do to percieve a higher one. So, in order for most of us to percieve a sinusiodal signal around 20 or 30 Hz, the amplitude must be higher than that of say a 1kHz signal. The 20Hz estimate is a generally good one because rarely can anyone percieve a sinusiod with that long of a wavelength without significantly increasing the amplitude. I'm pretty confident that I cannot pick up a 20Hz sign wave and I recently shut down my sub experimenting with that same question.
    The same goes for the high end. we become notably less sensitive to sounds above 16 or 20kHz. FYI, exposure to louder sounds such as listening to your stereo too loud will take out those high pitches 1st.
    On the lower end of the scale a very blurry line exists between what we feel and what we hear and I do not feel as if anyone can make that distinction without an appropriately designed experiment. One may already exist but I'm not aware of it.
    I hope this helps.
    Allan
     
  8. John Cain

    John Cain Second Unit

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    Thx Alan, very informative.
    So my question is, what frequency would be optimal to cutoff a sub that can play down to 10Hz, without losing the "live sound" experience from instruments that can easily produce fundamental frequencies down to 16 Hz??
    I'm assuming the 16 Hz note has harmonics below it that make it sound/feel like a real mammoth pipe organ, right??
    Thanks guys,
    -- John
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  9. Allan F

    Allan F Agent

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    John,
    Not really sure. From a "hearing" standpoint there is no point in producing anything below 20Hz. Although, information that is felt may add value to the experience. Anyone have anything to say on this?
    Allan
     

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