What do you need on the sidelines as a movie rushes towards an action-packed climactic moment? A panicky voice is one that helps to heighten tension at a pivotal moment in the story. While there will likely be some action or person causing fear, the panicky voice just ramps that fear right up.
Typical genres that suit the panicky voice are horrors and action movies. You won't find the hero speaking this way but one of the hostages or a second-in-command or person being stalked will. They remind the audience of the already obvious stakes thus increasing tension and also making it a little harder for the hero to remain focused..
For those who enjoy thrills and do-or-die moments, the panicky voice helps create the perfect palette. When the bomb timer is running down or the enemy army has just broken through the barrier, the panicky voice is employed to really turn up the heat. The panicky voice is not one audience's will find themselves drawn to and may even be irritated by it, but if it was not there the moment of intensity would be a lot lower. This is the unwanted voice audiences rely on.
The panicky voice will be trembling, shaken and broken at low pitch but as the drama intensifies so does the voice. This voice is prone to dissolve in a wave of tears or end in a faint. But at its loudest and most inserted, the panicky voice will very likely become a high-pitched scream of desperation.