If energy can't be destroyed, then forms of energy like sound and kinetic would eventually become heat (like if you were to speak or hit a table). Is that right?

 

The other question I wanted to ask was, if things like sound will eventually be changed into an energy form like heat, do the sounds people and machines make everyday put a lot of heat energy into atmosphere/earth? I know that the energy used to speak is very low, but on the scale of all people in the world would it have a large effect?

In physics, heat is not a thing, it is a process. It is the transfer of energy under certain conditions. You appear to be referring to thermal energy, i.e. something we would measure as temperature.

 

The energy can eventually show up as phonons in a material, which would mean the temperature is higher.

there will be a little be heating as the vibrational energy from sound causes friction in materials, but it will be Very tiny.

The amount of energy it takes to significantly "heat" anything is relatively large, very loud noises will cause a very slight increase in temperature, but the sound "waves" travel in all directions, not one direct "beam" therefore the heating is spread among a very large "region". This heating effect would definitely be classed as negligible in most normal situations.

Hope this helps.

Of course, it depends on how much energy you have, and whether it can be concentrated.

 

http://ndeaa.jpl.nasa.gov/nasa-nde/medical/heating.htm

Oh ok, that makes sense.

Thanks for the help

Yes, people (and everything else) results in the production of heat. All of human activity, including things like industry and automobile use would put out quite a lot of heat into the atmosphere, enough to be measurable anyway. But it would be tiny compared to what the earth recieves from the sun.