Here is the full list of all 46 Silence - there are The Whispered World 2 achievements worth 1,000 gamerscore.
Let Renie and Noah both pop the bubble
Completed the prayer mill story with the life wheel
You finished chapter two
Look into the abyss
Spot plunges everywhere
Burn the swamp
Lick the mushrooms until you pass out
You finished chapter one
Drop the Noiseball
Prime the bomb
Finish the game without dying
Let Sadwick die every time it´s possible
You finished chapter three
Go through the mirror
Stay in Silence
Finish the game without using the snoopkey
Finish the game without skipping a text
Pull the world worm's tooth
Let Spot fly
Spot licked everything
Find all bugs
Find all possible Spot interactions
Don´t prime the bomb
Trigger the same game over sequence twice in a row
Let the mushroom fart ten times
Shoot the gate
Send Spot to Kyra
Fix the bomb without letting go
Use the magic boxes to change into all available Spot forms
Taste the everything in the swamp
Let the fish get the berries 3 times.
Hit Kyra
Discover every possible Spot form
Kick everything possible
Play with the shadows
Balance without falling down
Fall in all balance checks or fall in the same check 3 times
Listen to Kyra
Dive through the clouds
Get to the gate in 8 steps
Place candles everywhere possible
Sneeze over the candle
Grab 10 gold from the well
Completed the prayer mill story with the death wheel
Completed the prayer mill story with the dream wheel
Skip every puzzle