When we talk, our vibrating chords oscilate next air molecules which oscilate the next molecules and so on. Hence sound wave travels.
As we know, energy that reaches the destination is not the same one as the starting one because the voice receiver hears is definitely less loud.
Why energy does not reach to the end? The first particle oscilates which in turn makes next air particle to oscilate but why does not the first particle have the power to oscilate the next one with the same amplitude and where is this energy that first particle had transformed into as logically it does not transfer all of its energy to the next particle?
Updated Questions per conversation with @Questor:
Question 1: in your comments, you said: "In a perfectly elastic collision, in a universe composed complete of our atmosphere sound could travel forever.... However, your ability to perceive the sound falls off at 4𝜋𝑟2 due to the inverse square law." then, you also said: "In a 3d space with perfectly elastic collisions, sound does not "travel" infinitely because the intensity of the sound fades as the area of the pressure wave expands, until it reaches a point that it is imperceptible.". Which one is true ? both can't be. Since the intensity decreases with the distance increase.
Question 2: If there was no loss in heat, even with 3d space, we would still have the same effect of decreasing intensity on each point as the distance increases right ? because even if no energy is lost, energy now must spread out over larger area. if correct, then with the heat loss, not only energy is spread out over bigger region each time it spreads, but some of it even gets lost(converted to heat) which causes even less energy spread to the next spherical shell than when we had no heat loss case.
Question 3: In your 1d space example(perfectly elastic example), why would the receiver get the same intensity as the loudspeaker created ? The way I understood elastic collision is, if 2 objects collide, no KE should be lost, it should be the same afterwards the collision. but that doesn't mean the first moving air particle would give the whole of its KE to the next air particle which would cause the first particle to stop immediatelly. Is this what would happen ? but if so, then masses should be equal, right ? but we know that once particle 1 hits the particle 2, particle 1 doesn't stop completely, it bounces off, so it still has some speed. Which means it doesn't give all of its energy to particle 2. So not sure why 1D space, we would get the same intensity to the end even in perfectly elastic collision(with no energy transfered into heat or any other form)