-int linphone_core_start_echo_calibration(LinphoneCore *lc, LinphoneEcCalibrationCallback cb, void *cb_data);
+int linphone_core_start_echo_calibration(LinphoneCore *lc, LinphoneEcCalibrationCallback cb,
+ LinphoneEcCalibrationAudioInit audio_init_cb, LinphoneEcCalibrationAudioUninit audio_uninit_cb, void *cb_data);
+/**
+ * @ingroup IOS
+ * Special function to warm up dtmf feeback stream. #linphone_core_stop_dtmf_stream must() be called before entering FG mode
+ */
+void linphone_core_start_dtmf_stream(LinphoneCore* lc);
+/**
+ * @ingroup IOS
+ * Special function to stop dtmf feed back function. Must be called before entering BG mode
+ */
+void linphone_core_stop_dtmf_stream(LinphoneCore* lc);
+
+
+typedef bool_t (*LinphoneCoreIterateHook)(void *data);
+
+void linphone_core_add_iterate_hook(LinphoneCore *lc, LinphoneCoreIterateHook hook, void *hook_data);