A sound’s bandwidth independently affects how loud it sounds.

Evidence

The intensity and frequency of sound are not the only factors that determine the loudness - ​ the bandwidth is also a factor. The influence of bandwidth on loudness is referred to as spectral loudness summation. It is important to also understand the effects of changing stimulus bandwidth on the loudness of sounds, particularly because we listen to a variety of different sounds with different bandwidths on a regular basis and we use both narrow- band and broadband sounds in audiometric testing. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 759

Categorization

• DEFINE: Introduces ‘spectral loudness summation’ as the term for bandwidth’s effect on loudness.