I know it's impossible to hear audible sound in space due to the lack of air. But say on a moon like Titan. Any other planet/ moon that say we could theoretically land on with an atmosphere, could we hear audible sounds? Like volcanoes erupting or our own communication with each other. Can we hear sounds on other planets/moons with any type of atmosphere?
Yes we can. Since any kind of matter can transmit sound waves, we can hear sound on Mars or Titan or Venus or any place with an atmosphere. Things would sound different, though, for about the same reason your voice will sound different if you breathe in helium. Basically, the sound speed of the gas the sound is being created in matters -- helium has a faster sound speed than air, which changes the wavelengths of the sounds you make, which distorts the overall sound of your voice. For that matter, you've probably noticed that things sound different when you're under water than when you're in air.
Since planetary atmospheres are made of different materials and are under different conditions -- Titan's atmosphere, for example, is mostly nitrogen, like ours, but it's about four times denser than air at sea level -- sounds will probably sound quite strange, but we'd be able to hear them or pick them up with microphones.
So far, the only microphone flown to a planet with an atmosphere was on the ill-fated Mars Polar Lander, which crashed in the 1990s. Mars Phoenix was supposed to get a microphone, but a bug in the attached camera's software -- which was supposed to photograph the descent -- meant that NASA couldn't turn it on without risking the lander.