If the above two waveforms were sound waves, we would hear the wave louder. if the above two waveforms were light waves, we would see the wave dimmer.

To compute the net effect of two waves, we use the superposition principle, and we can call the resultant wave "superposed wave".
We can rewrite the sentence as follows:
"If the above two waveforms were sound waves, we would hear the superposed wave louder. If the above two waveforms were light waves, we would see the superposed wave dimmer."