From Arabic, Sadaa can relate to 'echo' or resonant sound, depending on usage and spelling.
Sadaa comes from Arabic, where it can be associated with echo or resonant sound depending on spelling and context. That gives the name a pleasingly self-referential quality: it sounds like what it means, with the repeated vowels stretching the idea of reverberation. The doubled a lets the sound linger, as if it were meant to be heard again.
Because of that sonic link, Sadaa feels less like a static label and more like an acoustic event. It is a name with movement in it, a sense of call and return. In modern use it can seem poetic and uncommon, carrying the atmosphere of open space, remembered sound, and a voice traveling farther than expected.
The repeated vowels let the name linger, which suits a meaning built around return. Sadaa has a quiet resonance that makes it memorable.