I use Oticon OPN S 1 aids (one generation older than the more). I use Beyer DT 770 Pro headphones with large closed cups with my aids and an iMac Pro computer at home. I don’t have feedback issues with the headphones and, as they have a closed design with reasonably good seal to my head around my ear, they passively reduce ambient sounds reasonably well.
I have also used the ConnectClip as cvkemp suggests - I need to use a Sennheiser (now EPOS) BTD 800 USB dongle with the iMac Pro to get a reliable connection to the ConnectClip. I do not need the dongle with an older MacBook Pro (15" 2016 model). The dongle was included when I purchased the ConnectClip when they were first available - I do not think they are included now. EPOS now sells dongles with a USB-C connector instead of the more usual USB type A connector - I have no experience with that version.
I’ve also used the ConnectClip to connect to a Cisco VOIP phone that has bluetooth at my office. The combination of the ConnectClip and the hearing aids shows up as a Bluetooth headset for the phone.
Note that the ConnectClip can only connect to one Bluetooth device at a time (computer or dongle or, in my case at work, the VOIP phone) and connects to the first available device. The clip can be paired to multiple devices.
Good luck,
Stuart