Recording video with loud noise, audio level slow to return to normal

[shaun3000]

We went to see the Big Boy locomotive, today. (Giant train) It was incredibly loud. In all of the videos I took, after the train passed it took several seconds for the audio level to return to normal. What is going on? Example:

iPhone 16 Pro running iOS 18.0.1

 

[FreakinEurekan]

What’s going on is that the train is super @#$&ing loud, and it takes the iPhone a few seconds to decide no more super @#$&ing loud noises are coming.

 

[BrianBaughn]

In other words, the automatic sound level input is slow to react to the change…and it's not adjustable I'd guess.

 

[MajorFubar]

Automatic level control, which quite correctly has a slow release. The pumping effect that would be generated by a fast release would in most cases sound ridiculous and would be intolerable.

I guess you weren't there in the 70s/80s/90s when portable cassette recorders, amateur movie cameras and amateur video cameras all had the exact same thing. Modern phones are no different.

 

[shaun3000]

I guess I’ve never recorded something that so rapidly went from quiet to loud then back to quiet. It seems to have very quickly adjusted the level down but it seems to me it took quite a while to return to normal. Is this different behavior from previous iPhones or versions of iOS? (The amount of time it takes to release)

I feel in the case of this video it takes away from the impact of the audio. Is it possible to adjust the audio after the fact or will it lose fidelity? (Can’t imagine there’s much to loose on this one)

 

[FreakinEurekan]

I feel in the case of this video it takes away from the impact of the audio. Is it possible to adjust the audio after the fact or will it lose fidelity? (Can’t imagine there’s much to loose on this one)

I’m sure you can tweak it a bit. But yeah, this is about the behavior I’d expect from any ANR recording.

 

[MajorFubar]

I guess I’ve never recorded something that so rapidly went from quiet to loud then back to quiet. It seems to have very quickly adjusted the level down but it seems to me it took quite a while to return to normal. Is this different behavior from previous iPhones or versions of iOS? (The amount of time it takes to release)

Nope. Short attack and longer release is pretty much the norm for ALC circuits and has been always, both in the digital and analog realm. (The only exception were/are broadcast limiters, but that's a different assignment entirely.)

I don't know what video editing software you are using but pretty much all of them, even iMovie, will allow you to put a slope on the gain. But like you said, I doubt you're missing much.