The header say it all. Atarting kontact will open 4 (?) speech-dispatcher sessions to pulseaudio easily visible through kmix. These connections should only be opened at need and closed after use!
I think this is a more general KDEPIM thing. I have disabled speech-dispatcher on my system, because it messes up other audio connections (videocalling apps and websites). In my logs, I see kmail, akonadiconsole, etc. all trying to open speech-dispatcher instances. This generates entries in the logs: Connection to speech-dispatcher failed at the warning level. (These should be at the notice level, because speech-dispatcher is optional no?) This part of the KDEPIM code needs some love, I think.