intermittent noise

[#1]

Now I'm pretty fed up.  For the last couple of weeks, my phone line has been getting intermittent noise (crackles, pops etc. - to be honest sometimes it sounds like a bowl of Rice Krispies amplified by about 100), but it is intermittent.  My profile has now been stuck at 250K for about a week.  I may as well just use a couple of tin cans and a bit of string!
I've tried plugging a phone into the master socket when it happens, and sometimes it goes quieter, but whether that's because I've unplugged and replugged the socket I can't tell, because it's intermittent  BT have done their usual checks and said nothing's wrong with the line (I think they'd say that, if the line was completely missing), and if I keep pushing for something to be done, I get the usual veiled threats about £100+ charges if they come out and nothing's wrong but it's intermittent so there's every possibility that they'll come out and the line will not be noisy.
I noticed yesterday that while I was listening to the phone, while taking about an hour to download quite a small file, I could hear computer noise on the line.  So now I come to my question (at last they say!) could my ADSL filter be causing this (therefore the computer noise on the phone line)  Or is it more likely to be just a bad BT line?
I hope this makes sense, and I can wait the 2 or 3 minutes, it will take for this to upload! 
John

[#2]

If you can hear computer noise that is almost certainly a duff filter

[#3]

@hulls  When you say 'computer noise' what do you mean exactly?
If it's a gentle rushing sound, hissing sound, or 'mush' type of thing, it probably is your ADSL signal you're hearing, and the filter is the likely culprit.
OTOH, if what you heard were audio tones or bleeps, then it's likely that your line is in intermittent contact with another line (fax, telemetry etc), which would more likely explain your 'crackles and pops'.

[#4]

to clarify - when i heard the noise it was while the router was resynching and it was just the same as I used to hear with a dialup 56k modem

[#5]

You got it oldJim. That's exactly it. Similar to the sound from a dial-up modem. (but quite faint).
John

[#6]

You need to try another filter.  Some are better than others.  I prefer Excelsus Z-420UK-A although other makes have also attracted good press (like ADSL Nation's XTE).

[#7]

Does the noise only happen when the adsl is connected try this test
Unplug any extention phones, extention cables, answer machines or fax (anything except the phone you will use to do the test!).
Plug a normal touch tone phone directly into the BT master socket.
Dial 17070, press option 2 (quiet line test)
You should hear 'Quiet Line Test' and then silence, there should be no pops, clicks, whistles, buzzing etc. If there is noise on the line, make sure it's not your phones connection to the socket (wiggle it about a bit) and that you are using the master socket.

[#8]

That sounds good Samuria.  I'll try that later today.  The problem is, of course, that it may be fine at the time.  I'm also going to buy a replacement filter.  (I might as well have a spare anyway)
John