I believe It's your brain misinterpreting the low frequency "silence", assuming the eardrum is encountering resistance in the form of pressure.
I saw a study on this, and it's very clearly caused by the low frequencies being canceled. If ANC is focused on everything from low mids up instead, leaving the low bass alone, this alleviates the ear pressure sensation.
I believe It's your brain misinterpreting the low frequency "silence", assuming the eardrum is encountering resistance in the form of pressure.
I saw a study on this, and it's very clearly caused by the low frequencies being canceled. If ANC is focused on everything from low mids up instead, leaving the low bass alone, this alleviates the ear pressure sensation.