What causes "low" or hard to hear calls?

Question

Well, this is a first post for landline question.
First I would like to say, I have local calls with Verizon and long distance with Att&t. We have 2 providers because well.. it was set up like that almost 20 years and we decided just to leave it as is. I think there is only 2 major providers here in the state of RI, Cox Communications and Verizon.
Comcast used to show ads here, but one year just disappared and I don't see Att advertising locally for internet service here either. I think Att became just a wireless company in this state.  
The question I have is that both Incoming and outgoing calls have been a mixed bag over these past few years. The calls all do go through and we do have a dial tone. The problem is with the calls itself. Sometimes it would be to quiet so that we can't hear the other person on the other side or they can't hear us clearly.  We don't get much calls nor do we really make to many calls. It is just a number for friends and relatives to contact us. Sometimes hanging up and redialing fixes the problem.
Does anyone know what causes a call to be to soft or quiet on one end? its not a huge problem and it happens only a few times I would say about 10% chance.  It hasn't become a problem yet, just becomes annoying when it does happen. Especially since we don't use the phone that much. 
What we tried:
1. Using different phones throughout the house during the problems and all phones seem to have the problem. Tried both cordless and wired connected phones quality remains bad so we tell them we will call them back or they should call again and that normally fixes the problem. There was one time I remember it didn't work but assumed since they were dialing from a cellphone it was just a cellphone problem on there end. 
Also.. No one in the house hold owns a cellphone of any kind, so if anyone wonders why we still have a copper land line. It is because we found no use for cellphones yet.
I would also like to add this house was made in the late 1930's, there is no NID box anywhere in the house. I have tried to look for it but it does not seem to exsist. It looks like it comes from the pole direclty to the house Which leads over to the electic panel where all the circuit breakers are. Some of the wiring looks bad so I don't even bother touching it. At one point the previous owners had a alarm system on the basement windows and it even has a fire alarm on the side of the house interestingly...
For people who have experience with phone systems... Somewhere in the basement there is a ringer. When we get a phone call. The basement litterly starts rining like a phone is connected somewhere, even if no phone is connected to the basment. Does anyone know exactly what that box or what device causes rining? I probally should find a way to dial the home phone to figure out where it is coming from.  That thing is loud as heck if I can find it I would disconnect it or at least find a volume to turn down the ringer. 
The basement is filled with a bunch of old wiring from an old alarm system that the previous owner had installed 20+ years ago. When we moved in we saw all this disconnected wire and all these wires rerouted. 

Answer 1

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Anthony_VZ
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