transmission crowing

how does this problem become evident?

Put the vehicle in gear and listen as you go down at least 90 with the clutch depressed. then throw the gear in neutral and take your foot off the clutch and listen .. then when the vehicle is stopped, gas and listen without pressing the clutch at idle.

It does not cause any problems in this way, there is no difference in the sound, but when I go in 2nd and 3rd gear, when I take my foot off the gas pedal, I feel like I hear a very slight humming while the engine is braking.

Either I felt a buzzing noise as I went faster in the silence last night. Thoughts of 90 or so are decreasing inconsiderably. but at 120-130 speeds, I feel a humming sound similar to the engine sound. I remembered whether the transmission was singing. I wasted. I pressed the clutch in gear. I hit the gas. no change. the speed decreases, the volume decreases. It's not a noticeable sound. it is not heard during the day. if there is zero asphalt or something .. however. what could be the source of this sound. As it increases with speed, it can be ball or ball.