The first statement matches what I have heard this year from numerous sources, both Ashkenazi and Sephardi.
I have heard a number of the items below from Rabbi Dovid Rosenbaum of Young Israel Shomrai Emunah. Any discrepancies from his actual Psak are my own fault. And of course, CYLOR.
In my Rabbi's Halachic opinion, listening to a Megillah reading by Zoom is a last-resort option, but only if you do not have the option of reading along from a Kosher Megillah. That is, listening to a live Zoom reading would be preferable to simply reading in a printed Megillah. However, he made it clear it is a last-resort option. He suggested that if you have a Kosher Megillah but do not know how to read it properly, reading it along with a recorded Megillah reading would be a good option. The advantage of a recorded reading is that it is less likely to have intermittent problems and therefore better for reading along with it. However, a record reading is not sufficient unless you can read along in a Kosher Megillah. A couple of suggestions for recorded readings are:
The basic premise, as I understand it, is that in order to fulfill the Mitzvah of Megillah, you must hear it read from a Kosher Megillah. There are two ways to do that:
- A Baal Koreh reading from a Megillah. Everyone directly listening (not Zoom or phone or radio) fulfills the Mitzvah.
- A person with a Kosher Megillah listening (recording, Zoom, phone, radio) and saying every word along with the broadcast voice while reading the Megillah. This person is able to hear his/her own voice reading the Megillah (i.e., this should not be reading with eyes only) and therefore fulfills the Mitzvah even though he/she does not know how to Layn the Megillah without assistance.
The second situation is being recommended by many authorities in the current situation for those who are unable to directly hear a Megillah reading due to medical concerns. Of course, this is not so easy as the average person does not have a Kosher Megillah and they are in short supply this year.
There is an additional variation:
If someone is listening (directly) to a Megillah reading and misses a word (e.g., due to Haman noise or any other reason), he/she can repeat just that word, plus catch up to the Baal Koreh if that means missing another word in the process. That is ideally done from a Kosher Megillah rather than a printed Megillah, as then every word is read (most by the Baal Koreh, a few by the regular person) from a Kosher Megillah. This is permitted (just heard from my Rabbi) for words or phrases from a printed Megillah, provided the beginning and end are heard from someone reading from a Kosher Megillah and the majority is heard from someone reading from a Kosher Megillah, which matches the Halachos of what makes a Kosher Megillah (unlike a Sefer Torah where even a single letter makes it Pasul).
That being said, it is not a requirement and in fact, my Rabbi recently noted that he always follows along in a printed Megillah so that he can fulfill his requirement of correcting the Baal Koreh if needed, which he could not do if he were following along in a Kosher Megillah.
As to exactly why hear does not apply to phone/Zoom/radio, that is an interesting question. I heard, anecdotally, many years ago that they would have somebody read Megillah over the radio in Israel for the Egged bus drivers. I don't know whether that was a real thing or not, because aside from the question of whether radio counts as "hear", (a) a bus driver's shift (night or day) would typically allow for a real Megillah reading either at the beginning or the end of their shift, and (b) I can't imagine that a bus driver could actually listen to the whole Megillah without numerous interruptions. But clearly this issue is not a new one for medical, work-related and other reasons.
The first telephone systems had a simple microphone and speaker but no analog-digital conversion. A modern phone system (wired or cellular) has analog-digital conversion, packetization, multiple transmission media types and sometimes deliberate sound transformations - e.g., cut off the highest frequencies. Zoom (or any audio or video conferencing system) adds another complication - other users' sounds can be mixed in at any time, possibly even blocking the primary channel. Radio has similar complications. The end result is that while conceptually it is "sound in, sound out", the reality is far more complex, and each new generation of technology makes it more complex internally even while making things easier and better (connect "anywhere") in other ways.