Max distance humans can talk to each other?

Trying to figure out how far (prefer in feet) can two average humans talk to each other before yelling.  Let's say one setting is outside in a field, no wind nor animals.  The other setting is in a hallway.   

9 Answers

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  • Tom
    Lv 7
    4 weeks ago

    The VOLUME of different peoples voice may VARY---so no rules can be made unless we look for other parameters.

  • Joe
    Lv 4
    4 weeks ago

    Can you hear me now?      Can you hear me now?      Can you hear me now?

  • 4 weeks ago

    First, let's see what mathematics says.

    According to the inverse proportional law

    L2 = L1 + 20 log(d1/d2)

    L1 is sound level at distance d1

    L2 is sound level at distance d2

    log is logarithm with base 10

    If levels are given and we need to solve for d2 then

    (L2 - L1)/20 = log(d1/d2)

    10^((L2-L1)/20) = d1/d2

    d2 = d1 10^((L1-L2)/20)

    Let's suppose normal "outgoing" speech has level L1=70dB at d1=1ft.

    The theoretical hearing threshold is 0dB in lab, but we certainly can't distinguish words at that level. It is usually assumed that whispering is 30dB. We shall take 30dB for L2 so the distance where speech turns to whisper is

    d2 = 1 * 10^((70-30)/20) = 100ft

    Notice that L2 is arbitrary. If we take that lowest level when words are recognizable is 20dB (about as loud as rustling leaves), then

    d2 = 1 * 10^((70-20)/20) = 316ft 

    This is theory, with zero background noise like in the very quiet night with no city noise or crickets.

    In reality, this can be significantly changed with ambience effects.

    Observe two persons standing on opposite sides of a calm lake.

    Colder air above the water is denser and bends the waves down instead of letting them pass above the listener. Additionally, waves that go down into water reflect and skim above the surface toward the listener. This combined effect turns the air above water into a kind of sound lens that focuses the sound so it seems louder.

    Once I was sitting in a boat on the lake, it was a quiet night and some acquaintances were talking at the shore. They were about 250-300m (800ft) from me, yet I heard them clearly as they were beside me.

    In the military, they would tell you that sounds of cocking weapons and rattling of equipment can be heard as far as 300m (1000ft) at night. Imo this is additionally facilitated with psychological effects since metallic sounds do not belong in nature and easily stand out above the sound of birds and leaves.

  • 4 weeks ago

    It depends entirely on the acoustics of the venue. Greek amphitheaters were specifically designed to amplify sound. Someone speaking normally on stage can be heard hundreds of feet away. You need a lot more information on the people's surroundings in your example.

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  • 1 month ago

    I have at least twice experienced hearing a speaking person clearly from over 2 km away.  The ears are incredibly sensitive.  It is the absence of other sounds which makes it possible.  Your "hallway" completely alters the answer.

  • 1 month ago

    Define yelling in Db.

  • Robert
    Lv 7
    1 month ago

    You can't.  The Chinese weaponized flu will kill you if you speak to anyone in an enclosed space. 

  • 1 month ago

    need more details. hallways are inside buildings. There would be walls between that person and one in a field. Probably would not be heard at all.

  • 1 month ago

    Without yelling.

    I would guess about 50 feet. Just based on when I was a kid on the baseball field, talking to outfielders.

    Inside, down a hallway, probably 70 feet.

    Source(s): I never tried down a hallway.
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