A migraine aura is a set of sensations that some migraine sufferers experience before the actual migraine begins. In a way it is an early warning sign that a migraine is approaching.
Although with the word "aura" one might think that this was all about seeing halos, a migraine aura is much more than just visuals. It can involve smells, sounds, and mental confusion as well.
The main part, of course, is the visual perception. This can manifest in a variety of ways. There can be bright, curvy lights overlaid on normal vision. There can be sharp edged lines. There can be dark spots too, or tunnel vision. Since there is such a wide range of vision changes, it can be hard to distinguish a migraine aura from other forms of visual problems.
The hearing can be affected. Someone could be whispering and it could sound as if they're yelling. There could be buzzings or throbbings heard. There can even be hallucinations of sounds.
Smells can be strange - they can be stronger or unusual. Touch can feel too hot or cold. In essence every sensory input can be modified in ways never before experienced.
Add in to this that the general thought process can become muddied and slow, and you can see how confusing this can be!
A key here is to figure out what the typical signs are for YOU as a person, and how to know they are not signs of something else like a stroke. This would be where you involved a doctor and made sure you kept track of the symptoms carefully in a diary. That way you could be sure what was happening to you was a migraine aura and not something else.
Since these auras can be incredibly disruptive - imagine having this kind of an attack while driving! - it's a good incentive to work with your medical team to find ways to minimize the occurrences of migraines in general. That way you do not risk having a traumatic aura incident in a situation where it could cause injury to yourself or to others.
As always, consult with your medical professional to ensure your specific situation is examined thoroughly.