Honestly if it were me it would really get to me too. Even if WHAT they are yelling isn't necessarily abusive, the yelling in itself IS damaging to a child. However I don't think it warrants a call to CAS unless your gut tells you that should because there isn't much they can do about yelling.
And yes we all raise our voices sometimes but that's not what OP is referring to- this is CONSTANT yelling and it has no place in parenting and really, out of respect for their neighbors I'm not sure why they think constant yelling is ok anyways.
Always ensure that your child receives quality care by taking the time to investigate the provider and by asking for references! We simply cannot verify the claims of every daycare provider.
Updates
We expect providers to keep their listing and available openings up-to-date. However, to prevent oversights, openings expire after 45 days.