Michael Phelps' infant son, Boomer, has been watching dad from the stands in Omaha.

The only problem? That crowd is LOUD.

Phelps' fiancee, Nicole Johnson, could at times be seen putting her hands over the baby's ears as the sold-out audience cheered for the most decorated Olympian in history as he made his bid for a fifth Olympic Games.

On Wednesday, Boomer had a new look. He was sporting headphones to protect his little ears from the applause. Phelps' sister Hilary posted a picture on Twitter of the baby's star-spangled accessory: