Parcel delivery

Working at the post office, I'm used to dealing with a moody public. So when one irate customer stormed my desk, I responded in my calmest voice "What's the trouble?"

"I went out this morning" she began "and when I came home I found a card saying the mailman tried to deliver a package but no one was home. I'll have you know, my husband was in all morning! He never heard a thing!"

After apologising, I got her parcel.

"Oh good!" she gushed. "We've been waiting for this for ages!"

"What is it?" I asked.

Spoiler:

"My husband's new hearing aid".