Ear horn assembly for headworn computer

A head-worn computer, comprising:

• a. A see-through computer display configured to be mounted on the head of a user;
• b. A side arm configured to secure the see-through computer display to the user's head, the side arm further configured to be positioned to lay against the user's head proximate an ear of the user;
• and
• c. The side arm including a stiff member extending behind the ear of the user, contoured to substantially follow a curvature of the user's head behind the ear of the user, and to touch a portion of the user's head towards the rear of the user's head such that the see-through computer display remains substantially secure in a position in front of an eye of the user.