[pozitiffcat]

Чувак, кури TelephonyManager.CALL_STATE_RINGING
Вот на всякий, код с моего Flat Player-а

private void initPhoneListener() {
         PhoneStateListener mPhoneStateListener = new PhoneStateListener() {
            @Override
            public void onCallStateChanged(int state, String incomingNumber) {
                if (state==TelephonyManager.CALL_STATE_RINGING || state==TelephonyManager.CALL_STATE_OFFHOOK)
                        mPlayer.pause();
                super.onCallStateChanged(state, incomingNumber);
            }
        };
        TelephonyManager telephonyMgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        if (telephonyMgr != null)
            telephonyMgr.listen(mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);
}