Audio database is recorded under * conditions

Solution 1:

Such circumstances are usually called real-world conditions (i.e. - not controlled conditions).

Only my own opinion, but personally I think OP's suggested "realistic conditions" implies controlled, artificial conditions - although specifically designed to mimic real-world conditions, there's always a chance the testers either failed to set things up as they intended, or were unaware of some crucial aspect of the "real real" world.

Solution 2:

You might say under existing conditions, or imperfect, uncontrolled, run of the mill, flawed, as-found, ordinary, mediocre. Cornbread ninja's suggestion of everyday also is good, and its definition leads to commonplace (as well as ordinary, already suggested).