2021 Nissan Titan XD was being driven. I was listening to an audio book through android auto. I began to hear a noice I can best describe as a beep or squeal like you might hear from an electronic toy with a battery about to die. I thought the sound was coming from the center console and was trying to identify the source when I observed flames erupt behind the passenger door speaker grill. I exited the vehicle and opened the passenger side door where I patted the speaker grill and was able to extinguish the flame. I called 911. The call connected via bluetooth and I was able to hear the call through the other speakers. I pulled the door panel cover open and was able to observe the speaker was damaged. I reached in and pulled the connector out of the top of the speaker to hopefully ensure it would not reignite. The connector was not hot, melted or damaged.