How to lerp PlaybackLoudness?

I wanted to learn how to make stuff react to audio. I did some research the property I needed to loop into was PlaybackLoudness. I tested out this feature while changing the range of a PointLight on a part and it worked! Here is the code:

while wait() do                            -- \/ Located inside sound
	workspace.SoundPart.PointLight.Range = script.Parent.PlaybackLoudness/25
end

The problem with the script above is it updates REALLY REALLY quicky and the light flashes a ton! So I tried lerping.

To implement a lerp, I made this code below:

script.Parent:Play()

function lerp(a, b, t)
    return a * (1-t) + (b*t)
end

local prePlaybackLoud = 0
local postPlaybackLoud = 0

spawn(function()
	while wait() do
		prePlaybackLoud = script.Parent.PlaybackLoudness
		wait(1)
		postPlaybackLoud = script.Parent.PlaybackLoudness
	end
end)

spawn(function()
	
	while wait() do
		local ppL = prePlaybackLoud
		local pPL = postPlaybackLoud	
		for i = 0,1,.01 do
			wait()
			workspace.SoundPart.PointLight.Range = lerp(prePlaybackLoud/25, postPlaybackLoud/25, i)
		end
	end
end)

It seems to update 2 seconds late and it runs the lerp on the second before in the song. This was my final attempt before writing this question.

GOAL: I want to learn how to smoothly visualize audio on the range of a point light.