Sounds like a prime candidate for Amazon's Mechanical Turks. Vet & train a core group, and pay them to narrate pictures/video. Not hard work, not high pay, but

Sounds like a prime candidate for Amazon's Mechanical Turks. Vet & train a core group, and pay them to narrate pictures/video. Not hard work, not high pay, but (as a friend has found) there are competent people willing to do such work for humble pay.