Thanks checking. Yes I'll report this.

Nobody else uses AudioObjectShow()? This is what I get for treating Audio Devices like objects :-)

Here is another go at the program output. Sorry it's a mess here however I try to display it and it's only likely to make sense to folks looking over the code. The output looks best on the Xcode Console, if you just run the test program there. ID Device Name Manufacturer 0xd7 Darryl’s iPhone Microphone Apple Inc. ---------------------------------- Input --------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category HALC_ShellObject.mm:437 HALC_ShellObject::GetPropertyData: call to the proxy failed, Error: 1464353108 (WHAT) Error: getCFString(): AudioObjectGetPropertyData() ('WHAT'): The function call failed while doing something that doesn't provide any error messages. HALC_ShellObject.mm:437 HALC_ShellObject::GetPropertyData: call to the proxy failed, Error: 1464353108 (WHAT) Error: getCFString(): AudioObjectGetPropertyData() ('WHAT'): The function call failed while doing something that doesn't provide any error messages. 0 1 GET PROPERTY ERROR GET PROPERTY ERROR ID Device Name Manufacturer 0x41 LG UltraFine Display Audio LG Electronics Inc. ---------------------------------- Input --------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category 0 1 NO SUCH PROPERTY Front Left NO SUCH PROPERTY ID Device Name Manufacturer 0x3b LG UltraFine Display Audio LG Electronics Inc. ---------------------------------- Output -------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category 0 1 NO SUCH PROPERTY Front Left NO SUCH PROPERTY 0 2 NO SUCH PROPERTY Front Right NO SUCH PROPERTY ID Device Name Manufacturer 0x73 BlackHole 2ch Existential Audio Inc. ---------------------------------- Input --------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category 0 1 NO SUCH PROPERTY NO SUCH PROPERTY 0 2 NO SUCH PROPERTY NO SUCH PROPERTY ---------------------------------- Output -------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category 0 1 NO SUCH PROPERTY NO SUCH PROPERTY 0 2 NO SUCH PROPERTY NO SUCH PROPERTY ID Device Name Manufacturer 0xd2 MacBook Pro Microphone Apple Inc. ---------------------------------- Input --------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category HALC_ShellObject.mm:437 HALC_ShellObject::GetPropertyData: call to the proxy failed, Error: 1464353108 (WHAT) Error: getCFString(): AudioObjectGetPropertyData() ('WHAT'): The function call failed while doing something that doesn't provide any error messages. HALC_ShellObject.mm:437 HALC_ShellObject::GetPropertyData: call to the proxy failed, Error: 1464353108 (WHAT) Error: getCFString(): AudioObjectGetPropertyData() ('WHAT'): The function call failed while doing something that doesn't provide any error messages. 0 1 GET PROPERTY ERROR GET PROPERTY ERROR ID Device Name Manufacturer 0xcb MacBook Pro Speakers Apple Inc. ---------------------------------- Output -------------------------------- Stream # Chan Channel NumberName Channel Name Channel Category 0 1 1 1 1 0 2 2 2 2