Ep8 & Allegory?
If it isnt the exact sound forgive me, but if not, it is at least highly reminiscent of it (to me...) In whichever case, I take it as a sound effect for "waiting for the bad thing" (it is happening again, etc.) So the portrayal is thoroughly negative to me, and BOB-suggestive.
The Experiment/Mother throws up a couple of eggs that look a lot like the one that hatches the creature, too. As everyting is black and white, we can't be sure if the egg is a barfed egg or Laura's blob.
Write it in your diary
There are definitely intentional allegories in the show. I am glad someone else has noticed. I am currently an Undergraduate at University, studying History, and I recently began to specialize in Italian history, specifically cultural influence in the Renaissance/Early Modern period. The inclusion of Venus statues has also intrigued me. Venus had massive cultural significance to the people of that period, and she was interconnected with their world views and social identities. There is a Venus de Medici in the Lodge. Venus de Medici was important to Cosimo I Medici, Grand Duke of Tuscany. The Grand Duke is probably the Father of surrealism. Why? Because he funded and commissioned the growth of Mannerism. Mannerism, in my view, is the direct predecessor to surrealism, as surrealism is essentially modern Mannerism. I am not hinting at a wider hypothesis here, but it is nice to notice these little connections, in appreciation of the influences of Lynch and Frost. Would strike me as bizarre if they themselves were not aware of this train of connections.
NB: Cosimo I was obsessed with Alchemy. Alchemy, of course, if you subscribe to certain interpretations of Twin Peaks, plays a big role in the lore.
One interesting aspect about the Venus in the Black Lodge is that, during GoodCoop's departure back to Earth, the Venus TRANSFORMS into a version of The Arm that screams 'non-existant.' I previously speculated that this is actually The Arm's own doppelganger, who tried to destroy Coop before he could head back to Earth. Even the color of the head was different.