The inventory is designed to observe how a child responds to a variety of auditory signals (sounds) presented at different levels of intensity (soft to loud) in situations with varying background noise and distractions. Several observations should be conducted to develop familiarity with the child and his/her responses before attempting the FHI.

During the observation, the evaluator is looking for specific responses from the child to a variety of sounds in different environmental situations with varying degrees of background noise.