Telephone bug. When I answer all I hear are beeps?

I doubt you are being tapped. More likely someone is trying to send a fax to a wrong number.

@Coloma , so does a fax initially have a regular 1 second beep until it receives a response?
I always thought a fax sound was a series of more randomly pitched beeps?

@SeaTurtle

If it’s trying to transmit to a non-fax number it will make some very strange sounds.
Impossible to say for sure.
It might also be trouble in the lines being tested or worked on nearby or a mis-dial from a hearing disabled line.

I agree with @Coloma that someone has your number incorrectly attributed to a fax number they’re trying to reach. We get them at work, sometimes for hours.

It could also be a TTY-TDD device that a deaf person is using and calling a wrong number.

@WestRiverrat

Thanks for that..I could not think of the codes for TTY-TDD…aagh..my brain is in mis-fire mode today

Thanks people :)

Sounds like a fax machine. Apparently somebody entered your number by accident as one they are trying to fax a document to. Many fax machines will continue to call the number until they get a delivery confirmation from a receiving fax machine.