There are various rules pertaining to interruptions during the recitation of Shema. As first formulated in the Mishnah (Berachos 13a), there are certain interruptions that are allowed for "honor" and for "fear" or for "anyone".
בפרקים שואל מפני הכבוד ומשיב ובאמצע שואל מפני היראה ומשיב דברי ר' מאיר ר' יהודה אומר באמצע שואל מפני היראה ומשיב מפני הכבוד ובפרקים שואל מפני הכבוד ומשיב שלום לכל אדם
IN THE BREAKS ONE MAY GIVE GREETING OUT OF RESPECT AND RETURN GREETING; IN THE MIDDLE [OF A SECTION] ONE MAY GIVE GREETING OUT OF FEAR AND RETURN IT. SO R. MEIR. RABBI JUDAH SAYS: IN THE MIDDLE ONE MAY GIVE GREETING OUT OF FEAR AND RETURN IT OUT OF RESPECT, IN THE BREAKS ONE MAY GIVE GREETING OUT OF RESPECT AND RETURN GREETING TO ANYONE. (Soncino translation)
How do these laws apply to modern technology? For example, if someone in one of the categories calls you at a point that would be permissible to respond in person, can you answer your phone just like you could answer him in person? Or does the dispensation to interrupt Shema only apply when the person is physically in front of you and talks to you?
Is this discussed in any Rabbinic Literature?
(I am aware that a bunch of Acharonim cite the Sefer Hachinuch that the whole dispensation doesn't really apply nowadays even in person. My question is assuming not like this, so I would not consider this an answer. And even if someone would show that this is the unanimous consensus, it still wouldn't address the underlying theory of the question.)