If you have any DSL or ADSL filters on your line, please be advised that these begin to deteriorate after 12-18 months of constant use. It can cause interference on your telephone line which will be intercepted when connecting the call blocker to the line. To resolve this crackling or noise, remove all filters from the wall jacks, connect only the Call Blocker in series to a single phone, then re-connect each DSL/ADSL filter one at a time with each additional device one at a time, checking the line after each one is added to determine which one is causing the interference on the line. When you find which one is causing this, remove it and replace it with a new filter. This will resolve the issue for you and prevent any interruptions/interference or loss of Internet service on your line.
If you have any further questions, please contact us.