Negative SPL readings indicate levels below the reference threshold.
Evidence
If the actual level is less than the reference level then the result is a negative SPL. The decibel concept can also be applied to both sound intensity and the sound power of a source. — David Howard, Jamie Angus, coustics and Psychoacoustics, 204
Categorization
Category: Definitional Content
- DEFINE: Explains that negative decibel values are meaningful and simply signify sub-reference levels.
Related
- A decibel value is meaningless without an attached reference level (similarity 0.84)
- Sound level convention defaults to pressure level because it is measurable and matches hearing. (similarity 0.82)
- Reported sound levels almost always refer to pressure, matching human hearing (similarity 0.82)
- Amount of masking is expressed as a decibel difference, not an absolute SPL level (similarity 0.81)
- Sensation level expresses tone level relative to one individual’s own threshold (similarity 0.80)
- The factor of 20 in SPL makes one decibel equal a just-noticeable loudness step (similarity 0.79)
- Sound level meters measure pressure, from which intensity is derived (similarity 0.79)
- Sound pressure level is the standard because it matches hearing (similarity 0.79)