Yes, because when you switch on the mic on most Bluetooth headphones, it will switch to the headset profile and use the SBC codec in place of AAC. Also see here

Yes, because when you switch on the mic on most Bluetooth headphones, it will switch to the headset profile and use the SBC codec in place of AAC. Also see here for a longer description: https://www.recadio.com/blog/why-is-bluetooth-sound-quality-bad-on-my-mac https://www.recadio.com/blog/why-is-bluetooth-sound-quality-... Apparently newer generations of AirPods use the AAC-ELD codec which should improve this on Apple devices. You should be able to see in Console.app what codec gets used.