Try reducing the sample rate to somewhere between 11.025 kHz and 22.05 kHz. Go any lower and your movie will sound like someone talking on a cell phone while flying on a jet. Bits Bits are the amount of divisions in a sound sample cycle. The higher the bit rate, the smoother the sound will be and consequently the larger the file size. It is generally a good idea to keep your sound at 16 bit.
Mono sound on the other hand only has one track.
Obviously, you can reduce your sound size by 50 percent, simply by making your sound mono. Compression Codecs Sound, like video, has algorithms to help in compression. The trick is finding the best codec that works for you and is compatible with your viewers. Special Programs Finding the right compression scheme sweet spot takes a lot of trial and error. Luckily there are a few products on the market with preprogrammed compression settings that help reduce the time it takes to find the sweet spot.