At first, Mr. Khalifa said, the audio was recorded in a professional studio, with walls made of foam to absorb ambient sound. They used the software Magix Samplitude to edit the sound, and the finished productions were broadcast through a portable satellite dish.
But that all changed with American airstrikes in late 2014, Mr. Khalifa said. They had to relocate to urban centers starting with Raqqa, moving from house to house, aware that the proximity to civilians helped protect them.
As the Islamic State’s territory shrank, the media team was pushed out of Raqqa, but remained active, carrying the satellite dish with them, he said. They worried that the dish might give them away, but they continued transmitting nonetheless. In the final weeks before his capture, Mr. Khalifa estimated, there were at least 20 media operatives in the group’s last pocket in Syria, which has since been reduced to a tiny patch of land.
“Guys I knew agreed to work out of their homes,” he said. “They still took the risk.”
By the time he was apprehended last month, Mr. Khalifa said he had stopped working for the media unit and had picked up a Kalashnikov rifle to defend the Islamic State. Officials with the Syrian Democratic Forces said he had tried to attack their position. Mr. Khalifa said he had approached a villa, entering from below while soldiers were on an upper floor.
After a protracted gunfight, he said, he was bleeding and alone. The videos he had narrated were full of bravado, his voice representing a group that had vowed never to give up. But after more than six defiant years in the battle zone, Mr. Khalifa said, he did something that he never thought possible.
“I was exhausted. My ammo was gone,” he said. “They kept calling on me to surrender, and so I threw down my weapon.”