I am looking for a device to create a "personal zone" to prevent other from hearing what I say. E.g., if I seat in an open space office and give a phone call, I don't want other people to hear me.
I am aware of:
Muzo, which has a "Secret mode to protect speech privacy by Sound Masking", but the product isn't available yet (expected release date: spring 2017) and some people weren't so optimistic about it on reddit.
stenomasks, but there are quite uncomfortable.
Since this Stack Exchange website focuses on electronic devices, if you have some ideas that doesn't involve electronic devices, you're welcome to share them on this question posted on Home Improvement: Isolating a workstation located in an open space office.