Null Test
Definition
A technique for comparing two audio signals by inverting the polarity of one and summing them together. If the result is complete silence (a null), the two signals are identical. If residual audio remains, the signals differ by that amount.
Context
Null testing is commonly used to verify that different DAWs produce identical Summing results, to compare plugin processing between formats, or to check whether a bounce is bit-identical to a real-time playback. The technique has been used by community members to demonstrate that all major DAWs sum audio identically when given the same input.