When you end your cover letter with “I look forward to hearing from you”, or “please call me to arrange an interview”, this puts the ball in the readers court, and means you now have to wait on them.
It’s always a good idea to keep the initiative with you, and closing with a confirmation you will be in touch in a few days makes sure you keep the ball rolling. Of course, if you have no way of contacting them, or they explicitly state no phone calls, then you have no option but to wait.
Example Closings
I can see a great opportunity for me to contribute to the success of Abacard Corporation and I enclose my resume for your review. I will contact you again in 3 days time to schedule a meeting.
or
If you need more information, I can be reached at 111-111-1111, and I’ll be more than happy to discuss how my skills meet your needs. I look forward to hearing from you.
or
I have interested in openings with Abacard Corporation, and feel this opportunity is a perfect fit for my skills and abilities, I will call you on Oct -18th to confirm you received my resume and to answer any questions you may have.