Which audio interface standard (or API) does macOS use?
Apple's main low-level Audio Framework / API for macOS 10.0+ is Core Audio .

https://developer.apple.com/documentation/coreaudio


  Framework
  
  Core Audio
  
  Use specialized data types to interact with audio streams, complex buffers, and audiovisual timestamps.
  SDKs
  
  Overview
  
  The Core Audio framework (which is not an umbrella framework for the other services in Core Audio, but rather a peer) declares data types and constants used by other Core Audio interfaces. This framework also includes a handful of convenience functions.




Apple actually supports multiple frameworks &amp; APIs, including AudioUnit &amp; OpenAL.

Core Audio is actually based on OpenAL.