Is it okay do record runs without sound?
as far as i know yes. if remember correctly, i did a bowling pro class run without sound and it got accepted. im 99% sure you will be fine.
To quote the "Game Rules" tab,
"Game audio is not required but heavily recommended to further validate your run."
So game audio isn't required, just very recommended.
Audio is not required, especially if you use a camera pointed at a TV to record. That should be enough.
Proof Standards Changes
In the past, runs below a certain threshold could be submitted without video. Now, this system has been removed. All runs require video proof from now on.
Speedruns récents
[WSO] A Few Stamps
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30m 00s
BRONZE BARRIER
[WSO] A Few Stamps
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25m 00s
SILVER BARRIER
[WSO] A Few Stamps
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23m 00s
GOLD BARRIER