Dialogue (in greek dialogos) is a speech therapy center which cures people with speech problems.
The idea was to combine a spiral with the first greek letter of the word.
The spiral symbolises the infinite capabilities of speech.
Both symbols (the letter and the spiral) are very common because they're rounded.
In combination a harmonic result can be achieved.
The style of the design is handwritten to achieve a friendly style (actually I made it by hand :P).
This was made because of the speech problems start at the very young age.