Sonars comes from "
sound
navigation
and
ranging".
http://en.wikipedia.org/wiki/SonarThe Spell "Silence" affects it (SR4A p.209).
In SR4A, p.333 § why the item named "Ultrasound" (which is a sonar) is listed under "Vision enhancement" and not in "Audio enhancement" ?
You need both a sound creator and a microphone, you can't capture ultrasound with cameras.
Lots of blind people use the same technic, studying sounds reflections, to perceive the environnement : this being an audio enhancement makes sense, does it ?