Losing Key Pad Features - Several phone lines unmuted on speaker phone can lower the phone signal to the point of not being able to use the key pad functions on your phone (example *1 to mute and unmute, *5 for moderator to clear the noise on the meeting).
Hanging up and dialing back into the phone meeting can sometimes allevate this situation.
Phone Bridge Static - Even muted though not speaking, using speaker phones or the mute function on your individual phones to listen to the meeting can be the source of the static and weakens the quality of sound on the phone bridge.
Contacting Your Phone Provider - Sometimes contacting your phone provider can assist us in testing your individual phone line.
Calling into the Meeting Earlier - Several calls coming into the meeting can cause an overload not allowing some calls to come through.
Using the "Redial" function on your phone for the same call will still come through on the same signal. Calling another random number (like your cell phone) to break the original blockage, then calling the meeting can allow your call to go through.
If All Else Fails - Let Go and Let God.