A little bit louder now: negative affect increases perceived loudness.

Traditionally, perception was considered to be an encapsulated process that was unaffected by top-down processes like affect. Recent work in vision draws this framework into question by showing that changes in the affective state of the perceiver can impact many different aspects of visual perception. Here, we extend the relationship between affect and perception into another perceptual modality: audition. Participants were induced into a negative or neutral mood by writing about a frightening or neutral experience in their past. They then listened to a series of short, neutral tones (320 and 640 ms) and rated the loudness and duration of the tones. Participants in a negative mood rated the tones as significantly louder, but not longer, than participants in a neutral mood, suggesting that the difference between the groups was perceptual rather than just a response bias. This research shows for the first time that the role of affect in perceptual processes may be more pervasive than previously considered.