I forgot to wrote that I also supposed that my problems may source from no-venting earmold. The issue of earmold was mentioned above, hence I raised this issue in this thread.
Reduced venting can help with reducing background noise to make voice stand out better. However, with hearing in only one ear, I don’t see how it could help with directionality.
It isn’t necessary to have both ears to get directionality function from one hearing aid, although it is less effective than with z two HAs L+R. Not to mention the scene microphones (e. g. cardioid or supercardioid) have also directionality. However it isn’t possible to locate the sound with only one ear.
You’re right in thing that reduced venting isn’t helping directionality in literal sense e.g. making narrower spatial range of taking sounds. However, reduced venting increasing effectiveness of directionality, which makes better signal-to-noise ratio in the same degree of directionality than in more open fittings hence mental shortcut: “reduced venting increases directionality”.