In a universe where 'aether-sonis' exists, providing a medium for sound transmission in space, the experience of witnessing an explosion from the cockpit of a nearby spaceship would differ significantly from traditional expectations based on the conventional vacuum of space.

**Visual Experience:**
From the cockpit of the spaceship, the crew would first see the explosion. Light travels much faster than sound (approximately 299,792 kilometers per second), so the visual spectacle of the explosion—the brilliant flare, the expanding debris, and possibly a shockwave of rapidly dispersed matter—would reach the observers almost instantaneously compared to the sensation of sound.

**Auditory Experience:**
In this hypothetical universe, the 'aether-sonis' allows sound waves to propagate through space. Therefore, after seeing the explosion, the crew would hear it as well. The sound might range from a sharp crack to a prolonged rumble, depending on distances and the nature of the explosion.

**Time Delay:**
Despite the presence of 'aether-sonis,' there would still be a significant delay between seeing the explosion and hearing it. This is because sound waves travel at finite speeds. In Earth's atmosphere, sound travels at approximately 343 meters per second; we might expect similar speeds in 'aether-sonis,' albeit adjusted according to its unique properties. Therefore, the crew would first see the explosion and, moments later, hear the associated sounds if they are some distance away from the explosion.

**Synchronized Experience:**
If they are extraordinarily close to the explosion, the difference between the arrival times of light and sound would be minimized, making the visual and auditory sensations seem more closely aligned. However, in general space battles, due to vast distances, the visual cue would precede the sound by a noticeable gap in time.

**Conclusion:**
In this universe with 'aether-sonis,' space battles would transform into sensory experiences akin to those within an atmosphere, introducing an auditory element alongside visual cues. This might change strategic dynamics, as sound could provide clues about nearby events even before visuals confirm them, creating a richer tapestry of perception during the intense moments of space conflict.