Bose has a feature on all headphones called "sidetone", this is meant to make an effect as if you're not wearing the headphones, but hurts your ears and makes using the mic on the Bose headphones UNUSABLE! Searching up sidetone shows no praise for the feature, with most complaining about the feature and wanting to get rid of it, and others saying it's not working properly or not enabled because they don't know better and have realised that sidetone is what is making CALLS and any other moment where you use the headphone mic UNUSEABLE! BOSE google sidetone, no-one likes it! READ THE AFR review

"feels muffled and unnatural. For one thing, it's difficult to sense how loudly you're talking."

"For all its virtues and premium price tag, QuietComfort scores a fail in this department. You either tolerate the muffled, unnatural sound of your own voice or you don't use these phones for making calls."

"Once alerted to the shortcoming, a search for "QuietComfort sidetone" soon proved we weren't alone in our disappointment. Some owners have wondered online whether a firmware upgrade might fix the problem, but we can find no response about that from Bose." -https://www.afr.com/technology/gadgets/reviews/bose-quietcomfort-35-series-ii-noise-cancelling-headphones-aim-for-solitude-amid-the-chaos-20180615-h11ggf