From what I've read moshi moshi was originally pronounced "moushi moushi" and comes from the humble form of the verb to say/speak - moushiageru.
I also found it interesting that the original telephone greeting seems to have been either "oi oi" or "kora kora", which is rough sounding "male speech". This was apparently due to the fact that the first telephone users and operators were exclusively men, but as female telephone operators started to become commonplace the greeting changed to the more respectful sounding "moushi moushi".
The repetition does indeed seem to because of the poor quality of the first telephone lines.
Nice! I wrote a script similar to this that triggers when I take a screenshot with Flameshot, OCR's the screenshot using an API and opens web page with the OCR'd text. I prefer to use a Japanese to Japanese dictionary when possible which I have as a browser extension (yomitan). I like that this approach doesn't require an external API.
I also found it interesting that the original telephone greeting seems to have been either "oi oi" or "kora kora", which is rough sounding "male speech". This was apparently due to the fact that the first telephone users and operators were exclusively men, but as female telephone operators started to become commonplace the greeting changed to the more respectful sounding "moushi moushi".
The repetition does indeed seem to because of the poor quality of the first telephone lines.