Sound engineers deal with sound and make it sound good. They record, synchronize, mix, or reproduce music, voices or any other sound.
And sometimes they’re the music police for concerts.
Sound engineers make sure that the musicians are synced up with each other. So they might dim the clash of drums, tweak up guitar strings and let the lead singer’s voice wail through the concert hall for an Über musical experience. So if you got no satisfaction from the speakers at a gig – that’s the sound engineers’ fault.
Thus they are important folk in making music, acoustics, and even movies (remember THX sound system?) sound good.
There are courses out there (Nanyang Polytechnic’s AV technology course for instance) that will teach you the basics. But to be really good, you’d need a ear for it, and plenty of curiosity and desire to investigate the aural spectrum.
Like Diego Stocco, a master sound engineer who makes music from the unlikeliest sources such as “clothes drying rack, pipes with water running through them, a burning piano, light bulbs, a typing machine, a bass made from a bedside table, and a ‘sonic washer’”