Our team is currently using the T3902 MEMs mic in the cellular modem signal chain in one of our wearable products. We're currently experiencing difficulty with echo cancellation and are investigating root causes. One potential root cause is mechanical coupling between mic and speaker but I'm also interested in investigating the role that mic pattern may play in this issue. Is there a part number with a pattern other than omni (cardioid, etc) that is pin compatible with the T3902? If so, I'd be really interested in giving it a try.