Popcorn sound from front tires

I have a popcorn sound coming from my left front tire when I come to a complete stop. I have a 2003 Ford Explorer and went to the mechanic and was told I need 2 front wheel bearings but I not sure that is correct. Can someone please help me out?

I would take your car somewhere else for a second opinion, it certainly could be the correct diagnosis, but I am a tad skeptical of both front wheel bearings going out at the same time.

Maybe both are not worn out, but it is common practice to replace both sides at the same time.