The singers, who are both regulars on U.S. reality programme The Voice, will be featured in a show called Hello World!, a six-part series about the wonders of the natural world.

The show, made in association with the World Wildlife Fund, will use musicians' narration and music to tell little known stories about animals in the wild in an effort to inspire conservationism for all generations.

Aguilera's episode will feature her song Light Up the Sky, and she will showcase the strategies of maternal caregivers in the animal world.

"I was thrilled when I was asked to come aboard to be part of Hello World as I had never done voiceover work prior and the experience was amazing," the pop star said of the project.

Meanwhile, Usher's episode, which will feature his track Stronger, will take a look at how adversity makes a sea turtle and red fox more resilient in their habitats.

"Not many people may know of my strong affinity for animals and nature," the singer said in a statement. "Hello World gave me an opportunity to not only look cool to my boys (sons), but also help introduce a new and modern way of learning about the world and the animals living within it."

Other artists taking part in the series are Ellie Goulding, Steven Tyler, Joan Jett, and Dave Matthews.

Hello World! will debut on America's Discovery Channel on 9 July (16).