Are you saying phones are silent now? A “ringing” sound isn’t just a sound produced by bells, it’s any loud noise and, AFAIK, always has been.
You’re wrong. Twitter themselves refer to the symbol as a “hashtag.” The word/phrase after it is known as a “keyword.” People conflated the two, which makes your reading technically wrong (even though it’s not, because of how language works).
https://support.twitter.com/articles/49309-using-hashtags-on-twitter
Don’t get me started on #hotwaterheater
phones might be silent or they might have some form of annunciator. a buzz is not a ring. Big Ben on my tape recorder is a recording of a bell ringing, my tape recorder doesn’t ring.
This was exactly what I thought of when reading the subject line.
Ring
I’m not a fan of calling # hashtag, but as others have said, I think that ship has sailed and it’s not a hill worth dying on. That said I think there are perhaps some changes in language worth fighting, because I feel like some changes hurt our ability to communicate, where ones like hashtag are, at worst, neutral.
For instance, I hate the use of “literally” when someone really means it as an intensifier because the word “literally” has a distinct and useful meaning that is diluted and makes communicating that concept more difficult. Someone uses it in a context where it’s not completely clear if it’s being used to mean that their idiom or apparent exaggeration is, in fact, meant to be taken literally, or they just really wanted to intensify it. I’ve actually had to ask “Literally literally or figuratively literally?” and I feel like the conversation has devolved into nonsense. So, I will fight that usage 'til the day I die.
So, again, while I’m not a fan of that usage, I don’t think I’ve heard anyone say “hashtag” out of the context of social media. Even if I did, it’s just yet another name for the symbol outside of the social media context, so I still understand what they mean. I don’t think you’re going to get a whole lot of responses from people who feel as strongly as you do.
It is a hash. If it is used to tag a word it is a hashtag. It is also a dollar sign.
So, you haven’t bought a new television lately, huh?
I can remember when televisions took a while to “warm up”, but I can also remember, not so long ago, when, if you pressed the button to change channels, the new channel would come on pretty much instantly. Now, not so much. Both the TV as a whole, when you first switch it on, and each channel each time you switch to it, takes several seconds to “boot”.
As in, “That’ll be #2.98, please.”
or #ATMMachine
In what currency?
So — That’s what a “hashtag” is!
I would say that #followedbysomewords is a hashtag, while the symbol used to convert the words into a hashtag is called a hash symbol. Wikipedia seems to agree: “Outside of North America the symbol is called hash and the corresponding telephone key is called the ‘hash key’”. Any Outside-of-North-Americans want to weigh in? If it is commonly called a hash and not a hashtag outside North America, I would think that the ship has not yet sailed.
I also think “octothorp” has a better ring to it and we should use it on all occasions. 
#mom, then.
“Pound thisisahashtag is a hashtag. Pound Sign is not.”
Obviously the OP never used a phone tree in the 70’s or 80’s! “If you’d like to leave your phone number, press the pound sign!”
But that’s almost the same as “It was never called a pound sign”. Sorta? Kinda? Nearly? Almost? In the right light? On the tagged fringes of? …never mind!
So we’re all just going to ignore that Twitter itself considers the # to be the hashtag? I’ll post the link again:
My phone vibrates. 
Man, I’m waging the war against forward slashes being called “backslashes” in URLs. (Heard it again on the radio today. Seriously, what the fuck? What are we all still using DOS, where most normal people would have ever had use for a backslash. When has a backslash ever been used in a URL? Is it even a legal character?) I have years to go before I catch up to “hashtag” meaning the hash symbol (although I’ll grant that one)
The guy who woke up from a coma from the 1980’s says: “Why do they want me to pound all these people? Most of them aren’t even attractive!”