Yes to ultrasonic glasses, and yes to an experimental hat system.

Hat system is a little more problematic, because hats can be worn in different locations that would not target forward (could be a bit to the side or too far up). And because hats are soft, you can feel the device pressing against your forehead. There was discussion of using a helmet, but I see even LESS people using that.

Ultrasonic glasses do work (with some issues), and have been around since the 80s. The earlier models used a sound to indicate an object, with pitch to indicate proximity. One common problem is that the sound can be a distraction to the environment. Would be interesting to see how such a system would fare with a bone conduction headphone system.

One issue with ultrasonic sensors are when encountering things that are mostly empty space. For example, chain link fences or metal wires. A cane is a useful backup tool for that for low level items, but doesn't work for head height items. An example of an item at head level that the ultrasonic sensor (depending on sensitivity) may not detect is a bare branch, or a sign that is facing edgewise.