A speed which waves propagate in air mostly depends on temperature. When the temperature of air is higher, the speed is fast. In the opposite, when the temperature is low, the speed is slow.
Temperature is proportional to the mean kinetic energy of particles which are constituents of matter. That kinetic energy is derived from random motions of microscopic particles such as molecules. In this sense, “heat” is not a physical property of matter, it just means a shifting energy which is diverged to low from high of temperature.
On the other hand, 'sound' is wave or vibration phenomena which propagate in a medium -i.e. a periodic motion of the medium that typical one is air, but is also other medium. Generally the vibration which we can hear is called as sound. In this sense, sound is macroscopic motions of the medium.
Sound wave in air changes its speed by heat, and the acoustic also changes. The relationship between temperature and sound, that would become an important crossover point of microscopic view and macroscopic view, concerning our customary forms of perception.
Prepare several specific chambers which form a few pairs that have similar resonances, and give different thermal conditions to each one side of the pair. Emphasize the resonance for each chamber all by using microphones, loudspeakers and amplifiers. Each of the chambers on a constant temperature (left on room temperature) would make an each constant resonance, and the other chambers on varying temperature would make the changing resonances. By superposing all resonances, various beats arise in proportion to the different temperatures on each pair. Also peculiar changing frequencies of resonances appear caused by abrupt varying thermal conditions.
Through these changes of beats and the frequencies, we can observe 'thermal' world, that is microscopic air particles motions which are random and are difficult for us to perceive them easily on our custom. What we hear in order to observe the world is the changes of natural acoustics which are derived from relative differences of resonant frequencies, instead of the ton alities and harmonies as musical interpretation. That might show to us a shape of thermal world - where we live, and where it's essential, pure and disorder.