Which noise app are you talking about? The MoreSound Booster option in the ON app? That’s probably about the most aggressive forward beam forming setting you can get from the More. If you find it not helpful, maybe you can have your HCP create a custom program for you. Or are you a DIY’er since you seem to be asking pretty direct questions here?
Either you (if DIY) or your HCP can create a new program in Genie 2 and use the built-in Speech-in-Noise program as a starter. Then make sure that the Neural Noise Suppression is set to the max value if not already. Also change the Directionality Setting to Full Directional value, which is what you’re asking about, getting the mics to do front beam forming. If still not helpful, your HCP can start making more adjustment in the Fine Tuning section to experiment.
By the way, it’s not like one mic on the HA is front facing and the other mic is rear facing, and you can simply turn off the rear and leave the front facing mic ON like you think (as apparent in your original question). It’s not that simple. The hearing aid applies beam forming algorithm on the two mics on each aid to create 2 fixed acoustical “views” of the environment. One is an omnidirectional 360 degrees view and the other is a back-facing cardioid beam view. Then the system manipulates these 2 views to decide how to beam form, depending on the setting that you select for the directionality. Below is a screenshot showing what the back-facing cardioid pattern looks like (the dashed line) compared to the all-around 360 degree omnidirectional pattern (the circles).
