Horn of Calling

The Horn of Calling is a circular bugle horn made from a rare variant of brass. The horn can be held to the user's mouth to greatly amplify their voice as a loud speaker. It can also be held to their ear to enhance their hearing, even enabling them to hear tones that they would not normally be able to, making humans able to hear dog whistles and more. Additionally, the horns can be tuned to certain frequencies which allow them to communicate specifically from one horn to the other across great distances. Mages are also able to set up Horn Towers attuned to specific frequencies that allow them to broadcast sound to other attuned horns through a process known as Sonus Radio, often abbreviated radio. 
While it is possible to secure broadcasted frequencies so that only uniquely modified horns can attune to them, doing so is usually difficult and always risky. 
== Variants ==
=== Horn of Summoning ===
Horns of Summoning are specialized Horns of Callings that can call upon creatures to come to the location in which it is used. The Horns are generally attuned to attracting only one specific species, but more powerful horns exist that can call upon all animals who hear its blare and possibly even Ib.