@ktorn I got the audio track as a mp3 file and tried to do the Effect > Normalize in Audacity. But it still have those spikes.
I am not an audio expert, it seems to remove those spikes some kind of Limiter effect and/or probably need to manually edit the envelop of those spikes. Those items are beyond my bandwidth at this point.
The slides is https://rust-nyc-2019.localnative.app
I basically went over the links in the slide in the video, I hope the slides are useful if the audio does not work for you.