Ivan's Childhood (1962)

2002 MK2 DVD: Heavy noise reduction and a compensatory high-frequency boost. This is the worst sounding version by far. It has PAL speedup (a 4% increase in tempo and pitch), as you'd expect.

2007 Criterion DVD: This sounds pretty good. It has some mild noise reduction, but not much. The booklet says it was sourced from a 35 mm optical soundtrack print. 

2013 Criterion blu-ray: Like the Criterion DVD but with more hiss reduction, so it's more muffled (albeit less than other Criterion blu-rays).

2016 Artificial Eye blu-ray: Like the Criterion blu-ray; negligible differences.

2018 Potemkine blu-ray: Like the Criterion blu-ray; negligible differences.

2018 'unrestored' Mosfilm YouTube stream: I downloaded this in 2018 from Mosfilm's YouTube page. It's a unique version of the film in that it's riddled with visual and aural artefacts, being completely unrestored. Fidelity-wise, it sounds like the Criterion DVD but with less noise reduction - presumably none. I don't think it's still viewable on YouTube.

2019 'restored' Mosfilm YouTube stream: This, when it was still viewable on YouTube, was Mosfilm's own upload of their newest 2K restoration of the film from the camera negative. Its tempo is sped up in line with PAL speed-up, but its pitch is actually correct. It was clearly sourced from lower-generation elements than the print from which every earlier version came, since it's noticeably more detailed despite being less hissy. 

2019 Lumière blu-ray: As far as I know, this is the only blu-ray release of the new restoration. It's the best the film has ever looked. Its audio track has no downstream filtering relative to Mosfilm's YouTube upload. Unfortunately, it's pitched 0.71 semitones too low (the equivalent of PAL speed-up but in the opposite direction) despite being a 24.0 fps disc. Uncorrected: 1, 2, 3.