FLUTE SOLUTION

 
The large hole at the bottom end of the flute is used to play a sound. Each of the four smaller holes (numbered #1 to #4 in the graphic) can be covered with your sheet by clicking on it. Covering a hole produces a different sound when you play the flute.

Begin by playing the flute without covering any of the small holes. This activates Niels (the creature you freed from the locker and tube post) appearing in the top left corner. Listen very carefully to the noise Niels makes - it sounds like one of four animals, either a cow, cat, horse or frog. This is dealt with in more detail below.
 
Next, cover one of the small holes and blow into the large hole. Niels will answer with two separate noises, the first one indicates whether or not you closed the correct hole (in response to the animal noise he made previously) and the second will again be one of the four possible animal noises.
 
The aim is to identify each of the small holes with the corresponding animal noise that Niels makes.
 
The second noise that Niels makes is randomly generated, so there's no fixed solution.
 
Note: Disregard the sounds made by the flute and only concentrate on identifying the holes with the second noises that Niels makes.
 
 
The first part of Niels' response always indicates whether or not you closed the correct hole, i.e. the one that corresponds to his previous animal noise. These two noises are as follows:
 

He makes a 'happy' sound

Sounds like a baby crying

HOVER YOUR MOUSE OVER THE BUTTONS TO LISTEN TO THE NOISES

 
 
The second part of his response sounds very much like the sounds made by one of four animals, a cow, cat, horse and frog. The four holes correspond to the following noises:
 

Sounds like the 'moo' of a cow

Sounds like a cat screeching

  

Sounds like a horse snorting

Sounds like a frog croaking

HOVER YOUR MOUSE OVER THE BUTTONS TO LISTEN TO THE NOISES

 
 
You must correctly select seven holes in succession (without any incorrect choices between them) to learn how to communicate with Niels.