My Cockatiel's Name"Touille"

My Cockatiel Touille says sometimes "Touille!"
But I think that she doesn't understand this word as her name.
When she was still a baby,I asked her what she would take as her name.
She answered me "Touille!" I have called her Touille oder Toui since that time.
But she has misunderstood the meening of Touille.
I found that she meens Sadness or Loneliness with this word.
When she twittered "Touille!",I came to her quickly,because this twitter pleased me.

I blieve that she thinks that I come to her with this twitter.
When I get off from the Room, She says "Touille!",or when I let her alone.
Her "Touille" sounds a little sadly in such a situation.
She says this word,also when I stay by her, if she will play with me.
I think that she means with this word "I need you!"

It's very interesting for me.
Man can find it easily,how a cockatiel is pleased and gets angry.
But it's not so easy to understand Sadness or Loneliness of Cockatiel.