videos in AudioSet
A list of about a million ten-second YouTube clips, each labelled with the sounds in it, that Google published in 2017. Labs use it to train and test general audio and music models.
Including What does 3rd grade writing look like? - Milestones from GreatSchools, What does 2nd grade writing look like? - Milestones from GreatSchools, Does your 1st grader sound out words like this? - Milestones from GreatSchools