Table 1.

Examples of covariance in light, sound and chemical levels from natural and anthropogenic impacted environments.

combination of sensory conditions	correlated levels	examples from natural environments	examples from anthropogenic impacted environments	references
sound versus light	+	daylight and birdsong in temperate regions	traffic sounds and streetlights	[13–15]
	−	moonlight and insect sounds of tropical regions	reduced visibility and increased noise at water locks	[16–18]
sound versus chemicals	+	sound and chemical transmission in air/water currents	emission of sounds and chemicals by traffic	[19–22]
	−	?	?
light versus chemicals	+	pheromone release in relation to lunar phase	chemical and light pollution of industrial areas	[23]
	−	reduced visibility and increased CO2 levels due to aquatic vegetation	reduced visibility and increased nitrogen levels due to aquatic eutrophication	[24–26]