Audio engineers interested in recording music must have some background knowledge of music and its history. This musical context is the foundation for their work and can take many forms. Some engineers take a popular culture view on music appreciation and find sounds that worked in earlier recordings to enhance the track. Most audio engineers utilize their music knowledge to help isolate individual instruments and write musical arrangements to enhance their songs.
Audio engineers must also have a firm understanding of the psychoacoustic properties of sound. Phenomenons such as sound localization (the human ability to tell where a sound is coming from), equal loudness curves (how what we hear changes as the volume increases) and pitch perception are critical knowledge, helping an audio engineer find sounds that complement the material being recorded.
Equipment breaks and fails and audio engineers must be ready to repair their equipment when needed. Every piece of audio equipment has its own sound and many engineers develop their electrical skills to modify their microphones and processing equipment in a search for more interesting and true sounds.
Every sound source can be processed or effected and audio engineers specialize in the processing of these signals. From dynamics controls, such as compressors, to frequency filters, like equalizers, audio engineers must master all forms of signal processing to get the most out of their projects.