diff --git a/audio_common/include/audio_common/tts_node.hpp b/audio_common/include/audio_common/tts_node.hpp
index 27b0782..f26c2da 100644
--- a/audio_common/include/audio_common/tts_node.hpp
+++ b/audio_common/include/audio_common/tts_node.hpp
@@ -54,7 +54,6 @@ class TtsNode : public rclcpp::Node {
 private:
   int chunk_;
   std::string frame_id_;
-  std::string espeak_cmd_;
   rclcpp::Publisher<audio_common_msgs::msg::AudioStamped>::SharedPtr
       player_pub_;
   rclcpp_action::Server<TTS>::SharedPtr action_server_;
diff --git a/audio_common/src/audio_common/audio_capturer_node.cpp b/audio_common/src/audio_common/audio_capturer_node.cpp
index 0cdbe5b..7efd7e5 100644
--- a/audio_common/src/audio_common/audio_capturer_node.cpp
+++ b/audio_common/src/audio_common/audio_capturer_node.cpp
@@ -102,23 +102,23 @@ void AudioCapturerNode::work() {
 
     switch (this->format_) {
     case paFloat32: {
-      msg.audio.audio_data.float32_data = read_data<float>();
+      msg.audio.audio_data.float32_data = this->read_data<float>();
       break;
     }
     case paInt32: {
-      msg.audio.audio_data.int32_data = read_data<int32_t>();
+      msg.audio.audio_data.int32_data = this->read_data<int32_t>();
       break;
     }
     case paInt16: {
-      msg.audio.audio_data.int16_data = read_data<int16_t>();
+      msg.audio.audio_data.int16_data = this->read_data<int16_t>();
       break;
     }
     case paInt8: {
-      msg.audio.audio_data.int8_data = read_data<int8_t>();
+      msg.audio.audio_data.int8_data = this->read_data<int8_t>();
       break;
     }
     case paUInt8: {
-      msg.audio.audio_data.uint8_data = read_data<uint8_t>();
+      msg.audio.audio_data.uint8_data = this->read_data<uint8_t>();
       break;
     }
     default:
diff --git a/audio_common/src/audio_common/audio_player_node.cpp b/audio_common/src/audio_common/audio_player_node.cpp
index 4162866..2a9de13 100644
--- a/audio_common/src/audio_common/audio_player_node.cpp
+++ b/audio_common/src/audio_common/audio_player_node.cpp
@@ -80,7 +80,7 @@ void AudioPlayerNode::audio_callback(
                            std::to_string(this->channels_);
 
   // Check if stream already exists, if not, create one
-  if (stream_dict_.find(stream_key) == stream_dict_.end()) {
+  if (this->stream_dict_.find(stream_key) == this->stream_dict_.end()) {
     PaStreamParameters outputParameters;
     outputParameters.device =
         (this->device_ >= 0) ? this->device_ : Pa_GetDefaultOutputDevice();
@@ -90,17 +90,17 @@ void AudioPlayerNode::audio_callback(
         Pa_GetDeviceInfo(outputParameters.device)->defaultLowOutputLatency;
     outputParameters.hostApiSpecificStreamInfo = nullptr;
 
-    PaError err =
-        Pa_OpenStream(&stream_dict_[stream_key], nullptr, &outputParameters,
-                      msg->audio.info.rate, paFramesPerBufferUnspecified,
-                      paClipOff, nullptr, nullptr);
+    PaError err = Pa_OpenStream(&this->stream_dict_[stream_key], nullptr,
+                                &outputParameters, msg->audio.info.rate,
+                                paFramesPerBufferUnspecified, paClipOff,
+                                nullptr, nullptr);
 
     if (err != paNoError) {
       RCLCPP_ERROR(this->get_logger(), "Failed to open audio stream: %s",
                    Pa_GetErrorText(err));
       return;
     }
-    Pa_StartStream(stream_dict_[stream_key]);
+    Pa_StartStream(this->stream_dict_[stream_key]);
   }
 
   // Convert ROS message to array
diff --git a/audio_common/src/audio_common/tts_node.cpp b/audio_common/src/audio_common/tts_node.cpp
index b6a3dde..b0b5089 100644
--- a/audio_common/src/audio_common/tts_node.cpp
+++ b/audio_common/src/audio_common/tts_node.cpp
@@ -18,21 +18,20 @@ using namespace std::chrono_literals;
 using std::placeholders::_1;
 using std::placeholders::_2;
 
-TtsNode::TtsNode() : Node("tts_node"), chunk_(4096), frame_id_("") {
+TtsNode::TtsNode() : Node("tts_node") {
 
   this->declare_parameter("chunk", 4096);
   this->declare_parameter("frame_id", "");
 
-  chunk_ = this->get_parameter("chunk").as_int();
-  frame_id_ = this->get_parameter("frame_id").as_string();
+  this->chunk_ = this->get_parameter("chunk").as_int();
+  this->frame_id_ = this->get_parameter("frame_id").as_string();
 
-  espeak_cmd_ = "espeak -v%s -s%d -a%d -w %s '%s'";
-
-  player_pub_ = this->create_publisher<audio_common_msgs::msg::AudioStamped>(
-      "audio", rclcpp::SensorDataQoS());
+  this->player_pub_ =
+      this->create_publisher<audio_common_msgs::msg::AudioStamped>(
+          "audio", rclcpp::SensorDataQoS());
 
   // Action server
-  action_server_ = rclcpp_action::create_server<TTS>(
+  this->action_server_ = rclcpp_action::create_server<TTS>(
       this, "say", std::bind(&TtsNode::handle_goal, this, _1, _2),
       std::bind(&TtsNode::handle_cancel, this, _1),
       std::bind(&TtsNode::handle_accepted, this, _1));