Hardly Noticeable...

Think of all the moments when a hardly detectable ringtone would be useful. Listen:

 
It requires a certain level of sensitivity to need this ringtone, to use this ringtone, and to find it useful.
— Ringtone creator Tyia Wilson
 

subtle matters

Most available ringtones are abrasive to the ear.  This series of ringtones, beginning with Drone 1, will introduce a new approach to sound alerts.