SIL and SPL always change in proportion even where their absolute values differ

Evidence

However, changes in level for both SIL and SPL will be the equivalent because if the sound intensity increases then the sound pressure at a point will also increase by the same proportion. — David Howard, Jamie Angus, coustics and Psychoacoustics, 195

Categorization

Category: Causal Relationships

Related

• Sound power and intensity levels are unaffected by source correlation, unlike pressure level (similarity 0.86)
• Sound pressure level and intensity level coincide only without reflecting surfaces (similarity 0.85)
• Sound pressure level is the standard because it matches hearing (similarity 0.84)
• Loudness grows as a power law of intensity, not linearly. (similarity 0.83)
• Sound level multiplications become decibel additions in reflections (similarity 0.82)
• Intermediate separations cause loudness to follow intensity addition instead of pressure addition. (similarity 0.82)
• Sound intensity level and sound pressure level are roughly equivalent (similarity 0.82)
• Just-noticeable SPL differences stay constant near 1 dB across wide ranges (similarity 0.81)
• Roving sound level prevents listeners from using absolute intensity as a cue (similarity 0.81)
• Pitch strength rises only modestly with level while loudness explodes. (similarity 0.81)
• Reported sound levels almost always refer to pressure, matching human hearing (similarity 0.80)
• Loudness growth with intensity requires experimental quantification, not intuition (similarity 0.80)
• JNDL level dependence unifies across frequency when scaled to loudness level (similarity 0.80)
• Equalizing for a flat in-room response requires adding a high-frequency boost. (similarity 0.80)
• Relative magnitude judgments can be anchored into absolute psychophysical scales (similarity 0.80)