Recruiters understand the sensitivities involved when currently-employed candidates are applying for new jobs, and most will go out of their way to accommodate you. The initial telephone screening interview is a perfect case in point. Recruiters will try to schedule them first thing in the morning, during lunchtime or at the end of the work day so you can have this conversation on your time, when distractions are at a minimum.
Even then, you may have a hard time finding a private place to speak. But it's very important. Please avoid the temptation to conduct your interview during your commute, in an airport, or in a noisy office. And don't multitask--recruiters will know that you're not giving the conversation your full attention. Find a quiet place where you can be alone--your car is fine as long as you're not driving--and you'll make your best first impression.