hanging on every word

aware conscientious interested observant vigilant watchful

heedful

alert all ears awake enrapt enthralled fascinated glued hooked immersed intent listening mindful on one's toes on the ball on the job on the lookout on the qui vive preoccupied regardful studious

careless inattentive negligent unaware

disregarding heedless ignorant inconsiderate neglectful neglecting unattentive