I've been had this issue since last year, I write down my conclusion about this issue. I tested 10 different 15' 2016 model, and 2 different 2017 15' Model. I personally had a connection with Engineer Team through Agency in Apple. This thread is for helping people who are struggling with this issue. I'll offer the information what customers can do and what Apple will not do. 1. Reason of this issue - Thin Plastic Layer under the Keycap (Easily can be damaged by "heat", and "orders" with other parts) - Apple described this issue as "Inconsistency." - Reference https://forums.macrumors.com/thread...-clicking-sound.2022399/page-30#post-24485417 https://forums.macrumors.com/attachments/butterfly-jpg.708088/ 2. 2016 13' & 15' Model - Both models have "a potential defect with high probability." 1) Solution "Adding thin layer (it could be a shim or tape)" will prevent the noise. 2) Service that Apple will offers Setup the Shim under the keycap. 3) Service that Apple won't offer Revision of whole 2016 models 3. 2017 15' Model - Minor Keyboard Revision has been Confirmed. This revision prevents the high-pitched noise; however, the issue is not solved completely. Sensitive people will recognize the similar noise, but dull. I was able to confirm the dull sound (occurring by same reason). 1) Service that Apple won't offer Redesign the whole keyboard. - Reference https://forums.macrumors.com/thread...-clicking-sound.2022399/page-42#post-24723569 https://forums.macrumors.com/thread...-clicking-sound.2022399/page-42#post-24724141 4. 2017 13' Model Unconfirmed yet; however, many issues have been reported in the Forum. I guess Apple didn't have a revision in 13' model unlike 15' Model. PS. This issue is different with "Popping Noise Issue." My 1st language is not English.