We need an 'echo cancellation' or 'speaker feedback stopper' software which should be compatible with windows,mac and Ipad. Actually we use web conferencing software and moderator hears his own voice with those attendees who use 'speakers' instead of 'headphones', like their microphone catches the voice from their speakers which needs to be stopped, so that moderator shouldn't hear his own voice..
2 freelancers are bidding on average $550 for this job
We've got an experience of developing a considerably large-scale project for video conference. Echo cancellation was an important part of that project. You'll get just what you want in time, I am sure. Regards.