Helmholtz experimments...?
96815
Don't know about the reference...\n\nWhat I do know: music theory, and the theory of musical scales (particularly the mathematical description of scales) is a formal description of what sounds right (and wrong) to the human ear...
804155
a) T = 0.5 sec\n\nb) freq = 1/T = 2 Hz\n\nc) w = 2pi*freq = 4 pi\n\nd) w^2 = k/m\nk = m*w^2 = 0.5*16 pi^2 = 8*pi^2\n\ne)  V_max = A*2*pi*f = 0.35*2*pi*2 = 1.4 pi m/sec\n\nf) A_max = A*(2*pi*f)^2 = 0.35*(2*pi*2)^2 = 5.6*pi^2 m/sec^2
623872
there is a lot of research on sound/acoustics here is a good source of information http://www.livesoundint.com/
246943
I can't even play a radio without getting static, but my husband is a harmonica player and he plays whenever he feels like it. Not daily, but at least 2-3 times a week, usually during the afternoon. I wish he would play more, I love listening to him play.
1112020
okay, i found it.\n\n" While a tuning fork used in music is tuned to 440 hertz (the “A” note), seismic instrumentation and analysis determined the Earth’s free oscillation to be composed of pitches between 2 to 7 millihertz, fifty notes together packed within less than two octaves, ringing about 16 octaves below mankind’s musical “Middle C.”"\n\nso, 16 octaves BELOW mankind's musical middle c.\n\ni guess God has a really deep voice.\nvery cool.
885696
Earplugs. Seriously, they are lifesavers. Get the ones that have 32 decibels of attenuation. You'll never be bothered again.
121167
http://hyperphysics.phy-astr.gsu.edu/Hbase/surten.html
887961
Use the general equation for Doppler effect from here( http://en.wikipedia.org/wiki/Doppler_effect ). f'/f = .86 and v0 =0 for you since the observer isn't moving. Note that since the frequency is lower that it must be moving away from you.
305080
This may be helpful but I didn't read the entire thing.\n\nhttp://www.awc.org/pdf/NDSCommentaryCompressed/Part06RoundTimberPilespp85to88.pdf
444037
high fidelity!!! great music there.\n\nand something's gotta give ;)
712381
Good question!  I couldn't find one online that was free, but if you're serious about learning and hearing, check out the link below.
1105659
D'un point de vue mathématique, calculer la vitesse de la balle revient à résoudre un système de n équations différentielles avec conditions initiales. C'est un peu laborieux, donc dans la pratique on utilise effectivement un radar à effet Doppler, le plus souvent sous forme de canon.\n\n Ce radar est pourvu d'un émetteur à radio-fréquences (dans la gamme des micro-ondes) dont les ondes sont réfléchies par la balle en déplacement. Le délai de retour de l'onde est proportionnel à la vitesse de la balle. Ce délai est amplifié, filtré et analysé par une puce DSP qui pratique une correction d'erreurs et envoie les données analogiques à l'afficheur. \n\nA noter que les joueurs amateurs peuvent eux aussi chronométrer leur coup droit, grâce à un module de type Speed Trac qui s'accroche sur le filet. Ludique et pas trop cher.
173806
A jet engine is around 120db from 25 meters away, sorry i don't know conversion for miles.  I used to have a car stereo for competition and it would produce 152.4db if thats any help.  The bass can travel easily the distance you are talking about.  Permanent hearing loss starts at 90db so its most likely even with hearing protection he will still go deaf as he practically is sitting in a speaker box.  As for the volume going up its probably because he is already going deaf so has to turn it up, and on cold days when the air is more dense it will actually be up to an extra 3db louder, and also depending on wind direction.  Does this help?, in aus you can be fined for excessive car stereo noise! and even have your car confiscated!
947068
Don't give up too easily on the sound wave thing.  Graphic equalization.  Sound is measured in hertz (Hz) & Kilo Hertz (KHz), Kilo being the metric measure for 100.  Start with the low tones - long wavelengths, low number of hertz.  Move up the tone scale. As the tones get higher pitched the smaller the wave lengths - increased number of hertz. Super highs, like cymbals are in the kilohertz range and so on.  It's an everyday thing that everyone can relate to .  When you hear a siren go by the tone is lower as it approches and higher, faster, as it passes you and back to lower tones as the object receeds.  Good luck.
10261
All of these people worked on models to aid in acoustical design of ampitheatres (or any space where clearly hearing sound is important).  The three equations that you listed all take the same general form, and the latter two are subsequent improvements in Sabine's original work.\n\n"W.C. Sabine carried out a considerable amount of research in this area and arrived at an empirical relationship between the volume of an auditorium, the amount of absorptive material within it and a quantity which he called the Reverberation Time (RT). \n\nAs defined by Sabine, the RT is the time taken for a continuous sound within a room to decay by 60 dB after being abruptly switched off and is given by:\n\nRT = (0.161V) / A\n\nwhere V is the volume of the enclosure (m³) and A is the total absorption within the enclosure (sabine)."\n\n\n"Several different approaches have been used to derive equations which give values of reverberation time in better agreement with measured results from less reverberant rooms. One of these, the Norris-Eyring formula, assumes an intermittent decay with the arrival of fewer and fewer reflections. This gives the following formula:"\n\nRT = (0.161V) / (-S ln(1-a))\n\n"where S is the total surface area (m²) and a becomes the average absorption coefficient."\n\n"When the materials of a room have a wide variety of absorption coefficients, the best predictions are obtained by the Millington-Sette equation. This is simply a matter of substituting an effective absorption coefficient ae = -ln(1-ai) into Sabine's equation to give:"\n\nRT = (0.161V) / (sum(-Si ln (1-Ai))\n\nwhere Si is the surface area of the ith material, and Ai is its actual absorption coefficient.
902977
Simple....experimental
428070
Yo, this completely depends on how loud it is, and how short or long your attention span is.  As for me, it helps out alot. peace.