1 - I thought this image looked lonely and dark, and could imagine it pulsing lightly with the sound reverberating in the emptiness around it. I also feel that a slight hum from a light or another electrical appliance might work well as an auditory aspect to the brightness of the object.
2 - The second image reminds me a lot of a mixture between a deep-sea jellyfish and a human cell, causing me to imagine some underwater sounds with some bubbling and pulsing as well as a deep, yet somewhat faint heartbeat-like sound.
3 - The final image looks very natural to me, almost like windswept grass on a flat plain, which instantly made me think of the Mongolian Steppes. For this, I imagine grass blowing in the wind as well as other natural sounds (maybe birds tweeting, grasshoppers, a running river?).
I need to add more aspects to each of these to create more interest and less monotony. I expect I'll discover a fair amount while exploring and editing what I record but any input would help a lot