One period

One period

thumb|300px|right|This clip shows a band preparing where to position micsPhase plays a big part within the audio world. It can be used to increase amplitude or used for creative purposes. Phase can cause severe negative effects for an audio signal, in its purest negative form, it can completely cancel out a sound.

Phase is the term used to describe what stage a wave is in, within its its period cycle. As sound waves are emitted from the sound source they interact with other reflected waves, or waves from other sound sources. When they interact, issues arise dependent on the waves signature, as I stated before issues with frequency and amplitude occur.

A key problem when negative phase issues occur, is with mic placement. As the mics picks up sound from varying distances from the same sound source, the harmonics of the sound interact, can cause problems called comb filter, which generally not a desired effect.

thumb|300px|right|This clip explains audio phase.Here are some usefull websites :