Subject: Re: Physics of the sound of footsteps From: Leon van Noorden <leonvannoorden@xxxxxxxx> Date: Fri, 24 Jan 2014 09:34:08 +0100 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--Apple-Mail=_9AAC76AC-5095-49AF-AA5C-10017C3F5131 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 Dear list, I do quite a lot of walking to music. I noticed that you may be not so aware of the internal shockwave of your = footstep, but the shockwave makes your headphone move a bit on your head/ears. It is = difficult to suppress this sound/touch altogether. regards. Leon On 23 Jan 2014, at 12:27, Luca Turchet <turchet.luca@xxxxxxxx> wrote: > Hi Linda, > Bruno definitively suggested you the relevant literature.=20 > You might be interested also in my project "Audio-haptic walking = simulations=20 > for virtual reality, entertainment and rehabilitation applications", = which is=20 > basically a follow up of the NIW project mentioned before.=20 > I am using synthesis techniques based on physical and = physically-inspired models to=20 > simulate footstep sounds produced by different grounds, shoe types, = walkers with different=20 > anthropomorphic features, and different types of foot-floor = interactions. >=20 > Have a look to http://www.ahws-project.net/ >=20 >=20 > Thanks a lot Victor for sharing that interesting link. >=20 > Does any of you know if there is any study on the bone conduction = occurring during walking? >=20 > The topic is very interesting to me. For example perceptual effects = might arise when=20 > providing through headphones the interactive simulation of a foostep = on a ground different=20 > from that the walker is trampling on. Indeed, maybe beside to a = semantic or temporal=20 > conflict between the auditory and the haptic sensory information = during the integration of=20 > the two stimuli, there might be also a conflict between the auditory = information arriving=20 > through the air and the bones. >=20 > Any useful information about this topic would be very appreciated. >=20 >=20 > If someone of you is interested in starting a collaboration to = investigate such a topic=20 > using the technology I am developing please contact me.=20 >=20 >=20 > Best >=20 > Luca >=20 >=20 > --=20 > --------------------------------------------------------------- >=20 > www.lucaturchet.it >=20 >=20 > "Music is a moral law: > It gives a soul to the Universe, > wings to the mind, > flight to the imagination, > a charm to sadness, > and life to everything. > It is the essence of order, > and leads to all that is good, > just and beautiful, > of which it is the invisible, > but nevertheless dazzling, > passionate, and eternal form". =20 >=20 > Plato, 400 B.C. (from the Dialogues) >=20 >=20 > On Thu, Jan 23, 2014 at 9:19 AM, Victor Benichoux = <victor.benichoux@xxxxxxxx> wrote: > Hi all, >=20 > You may also be interested in reading this blog post by Romain = Brette: >=20 > = http://briansimulator.org/what-is-sound-xv-footsteps-and-head-scratching/ >=20 > Best, > Victor >=20 > On 22 Jan 2014, at 16:20, Mark Riggle <markriggle@xxxxxxxx> = wrote: >=20 >> How interesting you would be interested in the footstep. The human = walk is unique in producing that particular sound heard internally via = the skeleton. Our footstep has the foot hitting the floor with only a = vertical velocity (the horizontal is at or nearly zero). The foot-bones = stop so rapidly that the force on them causes a compression wave to = start there. That wave travels up the skeleton to the skull -- that = causes a high G (>1g) jerk on the head. That is what is heard and = vestibularly felt -- that shockwave is passing through the skull. = This is only in the human walk. In human adults it is referred to as = the heel strike transient. >> However, the earlier developmental walks (infant and young child), = although mechanically different, will also produce that audible = shockwave. >> So search for heel strike transient. The audible effect however = seems ignored - only the high skeletal jerk is investigated. >>=20 >> What is interesting to me is this is the same pattern that occurs = with very loud rock-music. The walk produces about 120 bpm of a = vestibular jolt (that could produce a VEMP response) that is also = audible, and when rock-music is louder than about 95 dB, it does the = same.=20 >> That is not a coincidence that these are only in humans. There are = some other human unique behaviors supporting that claim. >>=20 >> If you do a study on the acoustic part of that shockwave, please let = me know. >>=20 >>=20 >>=20 >> On Tue, Jan 21, 2014 at 11:45 AM, Linda Seltzer = <lseltzer@xxxxxxxx> wrote: >> When we walk, we can hear our footsteps, even if we are walking = barefoot >> on a soft surface. However, the number of steps per second in = walking is >> below the auditory range. What is it about the impact with the = ground >> that causes the auditory signal? Are there papers on the acoustics = of a >> footstep? >>=20 >> Thank you for any information. >>=20 >> Linda Seltzer >>=20 >=20 >=20 >=20 >=20 > --=20 > --------------------------------------------------------------- >=20 > www.lucaturchet.it >=20 >=20 > "Music is a moral law: > It gives a soul to the Universe, > wings to the mind, > flight to the imagination, > a charm to sadness, > and life to everything. > It is the essence of order, > and leads to all that is good, > just and beautiful, > of which it is the invisible, > but nevertheless dazzling, > passionate, and eternal form". =20 >=20 > Plato, 400 B.C. (from the Dialogues) --Apple-Mail=_9AAC76AC-5095-49AF-AA5C-10017C3F5131 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html = charset=3Diso-8859-1"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Dear = list,<div><br><div>I do quite a lot of walking to music.</div><div>I = noticed that you may be not so aware of the internal shockwave of your = footstep, but</div><div>the shockwave makes your headphone move a bit on = your head/ears. It is difficult to</div><div>suppress this sound/touch = altogether.</div><div><br></div><div>regards.</div><div>Leon</div><div><br= ><div><div>On 23 Jan 2014, at 12:27, Luca Turchet <<a = href=3D"mailto:turchet.luca@xxxxxxxx">turchet.luca@xxxxxxxx</a>> = wrote:</div><br class=3D"Apple-interchange-newline"><blockquote = type=3D"cite"><div dir=3D"ltr">Hi Linda,<br>Bruno definitively suggested = you the relevant literature. <br>You might be interested also in my = project "Audio-haptic walking simulations <br>for virtual reality, = entertainment and rehabilitation applications", which is <br> basically a follow up of the NIW project mentioned before. <br>I am = using synthesis techniques based on physical and physically-inspired = models to <br>simulate footstep sounds produced by different grounds, = shoe types, walkers with different <br> anthropomorphic features, and different types of foot-floor = interactions.<br><br>Have a look to <a = href=3D"http://www.ahws-project.net/">http://www.ahws-project.net/</a><br>= <br><br>Thanks a lot Victor for sharing that interesting link.<br> <br>Does any of you know if there is any study on the bone conduction = occurring during walking?<br><br>The topic is very interesting to me. = For example perceptual effects might arise when <br>providing through = headphones the interactive simulation of a foostep on a ground different = <br> from that the walker is trampling on. Indeed, maybe beside to a semantic = or temporal <br>conflict between the auditory and the haptic sensory = information during the integration of <br>the two stimuli, there might = be also a conflict between the auditory information arriving <br> through the air and the bones.<br><br>Any useful information about this = topic would be very appreciated.<br><br><br>If someone of you is = interested in starting a collaboration to investigate such a topic = <br>using the technology I am developing please contact me. <br> <br><br>Best<br><br>Luca<br><br><br>-- = <br>---------------------------------------------------------------<br><br= ><a href=3D"http://www.lucaturchet.it/" = target=3D"_blank">www.lucaturchet.it</a><br><br><br>"Music is a moral = law:<br> It gives a soul to the Universe,<br>wings to the mind,<br>flight to the = imagination,<br>a charm to sadness,<br>and life to everything.<br>It is = the essence of order,<br>and leads to all that is good,<br>just and = beautiful,<br> of which it is the invisible,<br>but nevertheless = dazzling,<br>passionate, and eternal form". <br><br>Plato, = 400 B.C. (from the Dialogues)<br><div class=3D"gmail_extra"><br><br><div = class=3D"gmail_quote">On Thu, Jan 23, 2014 at 9:19 AM, Victor Benichoux = <span dir=3D"ltr"><<a href=3D"mailto:victor.benichoux@xxxxxxxx" = target=3D"_blank">victor.benichoux@xxxxxxxx</a>></span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px = 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div = style=3D"word-wrap:break-word">Hi all,<div><br><div><span = style=3D"white-space:pre-wrap"> </span>You may also be interested in = reading this blog post by Romain Brette:</div> <div><br></div><div><span style=3D"white-space:pre-wrap"> = </span><a = href=3D"http://briansimulator.org/what-is-sound-xv-footsteps-and-head-scra= tching/" = target=3D"_blank">http://briansimulator.org/what-is-sound-xv-footsteps-and= -head-scratching/</a></div> <div><br></div><div>Best,</div><div>Victor</div></div><div><div = class=3D"h5"><div><br></div><div><div>On 22 Jan 2014, at 16:20, Mark = Riggle <<a href=3D"mailto:markriggle@xxxxxxxx" = target=3D"_blank">markriggle@xxxxxxxx</a>> wrote:</div> <br><blockquote type=3D"cite"><div dir=3D"ltr"><div><div>How interesting = you would be interested in the footstep. The=20 human walk is unique in producing that particular sound heard internally via the skeleton. Our footstep has the foot hitting the floor = with=20 only a vertical velocity (the horizontal is at or nearly zero). = The=20 foot-bones stop so rapidly that the force on them causes a compression=20= wave to start there. That wave travels up the skeleton to the = skull --=20 that causes a high G (>1g) jerk on the head. That is what is = heard=20 and vestibularly felt -- that shockwave is passing through the = skull. This is only in the human walk. In human adults it is = referred to as=20 the heel strike transient.</div> However, the earlier developmental walks (infant and young child),=20 although mechanically different, will also produce that audible=20 shockwave.<br></div>So search for heel strike transient. The = audible effect however seems ignored - only the high skeletal jerk is = investigated.<br> <div><br></div><div>What is interesting to me is this is the same=20 pattern that occurs with very loud rock-music. The walk produces = about=20 120 bpm of a vestibular jolt (that could produce a VEMP response) that=20= is also audible, and when rock-music is louder than about 95 dB, it does the same. <br> </div><div>That is not a coincidence that these are only in = humans. There are some other human unique behaviors supporting = that claim.<br><br></div>If you do a study on the acoustic part of that = shockwave, please let me know.<div> <div><img = src=3D"https://mail.google.com/mail/images/cleardot.gif"></div></div></div= ><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On Tue, = Jan 21, 2014 at 11:45 AM, Linda Seltzer <span dir=3D"ltr"><<a = href=3D"mailto:lseltzer@xxxxxxxx" = target=3D"_blank">lseltzer@xxxxxxxx</a>></span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px = 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">When we = walk, we can hear our footsteps, even if we are walking barefoot<br> on a soft surface. However, the number of steps per second in = walking is<br> below the auditory range. What is it about the impact with the = ground<br> that causes the auditory signal? Are there papers on the acoustics = of a<br> footstep?<br> <br> Thank you for any information.<br> <span><font color=3D"#888888"><br> Linda Seltzer<br> </font></span></blockquote></div><br></div> </blockquote></div><br></div></div></div></blockquote></div><br><br = clear=3D"all"><br>-- <br><div = dir=3D"ltr">--------------------------------------------------------------= -<br><br><a href=3D"http://www.lucaturchet.it/" = target=3D"_blank">www.lucaturchet.it</a><br> <br><br>"Music is a moral law:<br>It gives a soul to the = Universe,<br>wings to the mind,<br>flight to the imagination,<br>a charm = to sadness,<br>and life to everything.<br>It is the essence of = order,<br>and leads to all that is good,<br> just and beautiful,<br>of which it is the invisible,<br>but nevertheless = dazzling,<br>passionate, and eternal form". <br><br>Plato, = 400 B.C. (from the Dialogues)<br></div> </div></div> </blockquote></div><br></div></div></body></html>= --Apple-Mail=_9AAC76AC-5095-49AF-AA5C-10017C3F5131--