1) As attentive as Ross Perot 2) Attentive 3) Eager to hear 4) Eager to listen 5) Hanging on every syllable 6) Hanging on every word 7) Hardly daydreaming 8) Hungering for news 9) Like a good listener 10) Listening 11) Listening attentively 12) Listening carefully 13) Listening closely 14) Listening eagerly 
All ears is slang for attentive or listening.