I hit a deer with no bass in my car like 2 months ago. Made me think of this post I made a year or so ago...
I have always had a decent sound system set up in my vehicle and have been driving for 11 years mostly in the area of Cleveland, OH. We have a high population of white tail, as in many other areas in the Northeast region. Deer have become a nuisance to drivers, as a collision may cause serious damage to your vehicle and possible injury, or death. I always noticed that when I had the woofers turned up at night and exceeding 35 mph, white tail deer stimulus to the sound was not to fleed, but to remain still on the side of the roadway. I decided to do some research, and possibly try to determine the cause of low and high foreign frequencies to cause a deer to react this way. Keep in mind this is a hobby, (I'm not just bored) as I am a Biology major at my University.
White tail deer have a very keen sense hearing, with the ability to rotate their ears to pinpoint the location of sounds made in their environment, and possibly detect a threat to their survival. (Hunters should relate to this as sometimes they sound proof their equipment.) In 2008, research and studies done by Dr. Gino D'Angelo went against common thought that deer can hear much more extensively than humans. Of course we car audio enthusiasts know that audible sound waves are measured in hertz, or frequency. the human ear can hear frequencies from 20-20,000Hz. (boom) Our best and most sensitive range of hearing is in the 3000-5000Hz range as this is the range in which communication and conversations occur. Deer on the other hand, supposedly, can hear at best frequencies of 3000-8000Hz. So while true that deer hear optimally at a much higher frequency range than we do, their vocalizations generally are in the same range.
Now there there has been a multi-milion dollar industry created revolving around a product to try and prevent deer collisions. Deer whistles, or deer alert systems, attach to the bumper of a vehicle and play a high pitched frequency around 20,000Hz when your vehicle exceeds 35mph. Manufacturers advertising for these such products claim that ultrasound, is created by these whistles as air passes through them. Keep in mind ultrasound is a cyclic sound pressure wave with a frequency much greater than the upper limit of human hearing ability. Now the general effectiveness of these whistles is inconclusive due to conflicting reports available.
Ok. As we know a subwoofer creates lower end frequencies.(some have the ability to produce lower frequencies than others) A low frequency sound wave has a longer wavelength than higher frequencies, and travels farther than high frequencies, with a shorter wavelength property. These shorter wavelengths are more easily absorbed by the molecules in air, hence why they cannot travel as far as low frequency sound waves.
I believe that the reason a deer will react in this way while I'm bumpin' by them with some chopped and screwed, (wildlife demo) is that these low frequencies are actually audible to them; and at the same time, these frequencies are more foreign than any noises heard throughout their endeavor to survive and have no familiarity with these sounds. (of that 32Hz tuned slot port) So they hear you coming down the road rockin' out.......( Deer: "Wtf?" ) then they hear some "tisk tisk tisk" as you're bad ass four channel is got those vocals screaming...maybe when they hear these higher frequencies they are more alert in their sensivities to these frequencies and to avoid miscommunication between them and their environment, they pause, as they clearly know you are a moving vehicle now. (Although they have smaller brain casings than us humans, I'm sure they learn and adapt when their best friend gets plowed by a 16-wheeler.) (gore everywhere)
I have hit a deer once in my driving experience. It was around this time of the year and occurred at dusk. (the most collisions occur at this time simply to lack of vision and ability to brake accordingly) I in fact, did not have my stereo on at the moment and was not making any audible noises from my speakers.
(except alternator whine lolz) j/k This study may be as simply put that deer do not like dubstep, therefore give you the gangsta stare down; or this may be more complex in the manner that deer can determine changes in the environment through the kinetic energy placed into the air, and the combination of high and low frequencies grabs their attention, not scaring them. Example: If deer are as they say they are, "color-blind", they may have evolved advanced hearing techniques under natural selection to compete successfully in their environment. Ex. weather detection from wind intensity, thunder, exc. or the ability to label and react to certain frequencies to you and your hunting equipment despite of that orange vest you're wearing.
-"Deer Demos" by Greg Novicki