Holiday cards are placed inside the musical blue collection box outside USPS headquarters in Washington, DC.

Customers depositing mail inside one blue collection box this month are receiving some holiday cheer in return.

The box, which sits outside USPS headquarters in Washington, DC, plays clips from popular holiday tunes when customers open the door.

Engineering Systems designed the technology and is testing it through the holidays.

“It’s really fun to use technology in ways you’d never think of,” said Delivery Technology Programs Manager Will Tartal. “Who would think a collection box could play music?”

To create the sound effect, engineers placed a battery-operated module inside the box that does not use traditional speakers. Instead, audio transducers are mounted directly to the walls of the box.

When the door is opened, it activates one of several instrumental recordings, including “Jingle Bells” and “We Wish You a Merry Christmas.”

“The collection box is actually the speaker,” he said. “How cool is that?”

The module and audio technology don’t interfere with mail deposits or collection. A decal on the box tells customers about the test so they won’t be alarmed when hearing the music.

A man who used the box this week to mail a Christmas card heard “Up On the Rooftop” and offered a smile to a woman who was waiting to deposit a stack of greeting cards.

Said Tartal: “We have collection boxes just about everywhere. Technology like this offers a lot of possibilities for the Postal Service from marketing initiatives to even security monitoring.”

Source: USPS