A little free advice, er um maybe just my opinion, on DSL service or dialup in general.
Catagorically speaking, an occasional call to the telco to complain about "intermittent static on the line" or "hard to hear" will result in your number being routed to the cleanest lines and the best switching equipment the vendor has. Your DSL or dialup will benefit substantially from the cleaner lines. Those who make no noise and pay their bill appear to be systematically moved to the back of the bus. This has been my experience, can't say if it's policy.