Thought not, I did find out a little bit more about "soft dial tone":
Quote:
“This is know as 'soft' dial tone and it supports only '17070' and the RATS line
testing system. Calling into the number will also fail. Basically the line is
OCB and ICB and just carries the juice and dialtone with basic diagnostics.
The 'thinking' behind this is twofold.
(1) It is meant to stop BT engineers 'stealing' the pair of wires that is proper
to your property by making the line look 'live'.
(2) It makes it a software matter to re-provide the line to the premesis if you
so wish.
In reality, engineers still take the pairs that are 'TOS' (even with soft
dialtone) as line plant should be used for paying customers, not those that have
gone, and it's often the only way to provide lines where line plant is short.
They can look these lines up easily on the CSS database system to find them, but
can't sit easily in a joint 'clocking' through them for the old TOS tone.
The 'Soft' dialtone is not just percuilar to system 'x' exchanges, it also
appears on system 'y' too, although the delay between the dialing of a number
and 'dead' tone playing is a little longer on system 'y'.
Depending on how 'busy' your area is the dialtone may stay a week, a month or as
many years as BT decide it's the system they are using. ”