No, not at all. Silent Phone just encrypts the contents of the call. The only way to protect against traffic analysis is to go through multiple intermediaries, which is a technique that has been used to protect email and web browsing (see the TOR project for an example of this). But this adds latency to communications, which may be unnoticeable for email, and at least tolerable for Web browsing, but would be unacceptable for phone calls. Further, these countermeasures may be ineffective against a clever and resourceful opponent, because it’s hard to hide the timing and length of the messages, especially if there are real-time communication requirements.