Presentation method, room acoustics, and listener state are independent variables in listening experiments

Evidence

The way in which sounds are presented to subjects can also make a difference since the use of loudspeakers would mean that the acoustics of the room will alter the signals arriving at each ear (see Chapter 6) whereas the use of headphones would not. There may be background acoustic noise in the listening room that could affect the results and this may even be localized, perhaps to a ventilation outlet. Subjects can become tired (lis­ tener fatigue), distracted, or may perform better at different times of the day. The order in which stimuli are presented can have an effect—perhaps of alerting the listener to specific features of the signal, which prepares them better for a following stimulus. These are all potential independent variables and would need proper controlling. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2364

Categorization

• XREF: Connects to experiment design methodology broadly, and to the reader’s interest in applying psychoacoustic methods.