Absolutely, cell phones should be silenced during meetings. Best practices are that we show consideration of others during interaction. All meetings require that we are fully invested in the moment. To be distracted by cell phone use conveys you are not fully invested in the moment and could also send the message that my business is more important than what we are engaged in. I would silence my phone and return calls following the meeting. If it is an urgent call you are expecting, then excuse yourself from the meeting to answer a call.