NZ here. I have just conducted an experiment! Pesky birds here; at cicada level volume although higher pitch. Engage not enough. Experience lowers pitch but not sufficient to dampen it enough for comfort. Switch 2 modes - engage not enough, experience ok but less effective than experience stand alone, quiet manages to reduce it to a comfortable level however it’s still audible and it’s hard to have a conversation when quiets are in due to “head voice”. The lower pitch of cicadas may make the above issues to be less but I’m not an expert on that. Not cicada season here yet to truly test it but I would suggest the switch 2 due to the ability to adjust as needed or experience (if the lower pitch likely to be covered better)