I came across a pretty cool site this morning. It's pretty much like a Lumosity for sound people.....like us. Producers, engineers, and what have you. There are different games and such for picking out frequencies, gains, determining panning positions, etc. Believe me, this way of ear training is SIGNIFICANTLY more enjoyable than picking out a random boosted frequency in white noise. You can collect 'soundcoins' for completing training that can be used for discounts at MusicRow or on equipment for your account's virtual studio. You can also compare your profess to friends and other account holders. It's free to sign up too. Daily workouts are also free. A subscription opens up more access, naturally. Worth checking out tho, hope it helps!