Sound - how do you want it delivered ?

Sound conducts quite well through air. Yet, from farm experience I note that when a tractor passed behind a bonfire the noise from the tractor changed. That is, the fidelity of the waves passing through air of variable temperature is not absolutely true. Another point of note, transmision through air is energy inefficient. This latter point becomes evident when you try to converse with someone at a hundred yards by air conduction of voice.

Consider this too, if several people within a limited space produced loud music or noise, it creates a noise polluted environment. Thus, from three reasons, the collective brains of past and present engineers, saw a need to transduce the energy of air sound to other formats. Today, in a conversational voice, I can converse with someone in Europe, or elsewhere. The physical sound is used to modulate the electron movement along a wire, or to modulate electomagnetic waves into space, and then by reverse transduction physical sound is recreated. And, the vinyl record, the tape, the disc, and the ipod and mp3 allow for canned music and speach.

It is interpreted that undulations to the pressure on the ear (or vibration to the ear bone) is perceived as sound. And, if the rythmicity and harmony are enjoyable, then is loud better than quiet? Though music is an artistic blend of harmony and rythm when it is unwanted and imposed on anothers ears it is sound pollution, and, could be considered noise.

It has been established that prolonged exposure of the human ear to loud music or noise will damage it. From a single industrial survey I interpret that the initial increase in threshold (drop in accuity) occurs at 4000 hertz.

The question we want to pose is - can a small earbud headphone damage your hearing?

To consider relative energy concentration dropoff at different distances from the the source it is inferred that energy radiates out equally in all directions. The energy concentration varies inversely as the surface area of a sphere with the distance from the source as the radius of the sphere. The respective areas are, 2rx2rxpi. Since I find irrational numbers a pain, let me set pi = 3. For this comparison let us set that you listen to your computer speakers at 3 feet and the ear plugs are 1/2 inch from your ear drum. Accordingly, the energy density at 1/2 inch compared to the density at 36 inches is: 2x36/1/2x2x36/1/2x3, or, 72x2x72x2x3 = approximately sixty two thousand times as great.

Are you thinking that ear plug speakers are too small to do harm to your hearing? Think again about it!