Does the number of Participants affect the quality of a conference?

In any conference call, no matter what conference bridge or provider you use, the clarity will decrease somewhat as you add more Participants. The more conference Participants, the more likely the use of cell phones, cordless phones, speakerphones, headsets, background noise, and other low-quality transmission problems. Also, there is more chance of someone putting the call 'on hold' without remembering to mute their phone and broadcasting their 'hold music' or radio station to the remainder of the conference.

Basically, it is human error that causes problems