Controlled experiments convert listening hunches into identified causes by isolating variables.

Evidence

Psychoacoustic testing involves careful experimental design to ensure that the results obtained can be truly attributed to whatever aspect of the signal is being used as the controlled variable. This process is called controlled experimentation. A starting point for experimental design may well be a hunch or something we believe to be the case from our own listening experience or from anecdotal evidence. A controlled experiment allows such listening experiences to be carefully explored in terms of which aspects of a sound affect them and how. Psychologists call a behavioral response, such as a listening experience, the dependent variable, and those aspects that might affect it are called the independent variables. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2378

Categorization

• DEFINE: Introduces dependent and independent variables as the organizing vocabulary of psychoacoustic experiments.
• QUESTION: How many listening effects are actually multimodal, requiring whole stimulus sets rather than single controlled variables?