diff --git a/src/util/audio/AudioQueue.cpp b/src/util/audio/AudioQueue.cpp
index 8a456e09..60a28a9b 100644
--- a/src/util/audio/AudioQueue.cpp
+++ b/src/util/audio/AudioQueue.cpp
@@ -36,7 +36,7 @@ unsigned long AudioQueue::size()
     return deque<int>::size();
 }
 
-void AudioQueue::push(int *samples, unsigned long nSamples)
+void AudioQueue::push(int* samples, unsigned long nSamples)
 {
     XOJ_CHECK_TYPE(AudioQueue);
 
@@ -66,13 +66,17 @@ std::vector<int> AudioQueue::pop(unsigned long nSamples)
 
 void AudioQueue::signalEndOfStream()
 {
+    XOJ_CHECK_TYPE(AudioQueue);
+
     this->streamEnd = true;
     this->notified = true;
     this->lockCondition.notify_one();
 }
 
-void AudioQueue::waitForNewElements(std::unique_lock<std::mutex> &lock)
+void AudioQueue::waitForNewElements(std::unique_lock<std::mutex>& lock)
 {
+    XOJ_CHECK_TYPE(AudioQueue);
+
     while (!this->notified)
     {
         this->lockCondition.wait(lock);
@@ -81,10 +85,14 @@ void AudioQueue::waitForNewElements(std::unique_lock<std::mutex> &lock)
 
 bool AudioQueue::hasStreamEnded()
 {
+    XOJ_CHECK_TYPE(AudioQueue);
+
     return this->streamEnd;
 }
 
 std::mutex &AudioQueue::syncMutex()
 {
+    XOJ_CHECK_TYPE(AudioQueue);
+
     return this->queueLock;
 }
diff --git a/src/util/audio/AudioQueue.h b/src/util/audio/AudioQueue.h
index f62fdda9..788e055a 100644
--- a/src/util/audio/AudioQueue.h
+++ b/src/util/audio/AudioQueue.h
@@ -24,23 +24,26 @@ public:
     AudioQueue();
     ~AudioQueue();
 
+public:
     void reset();
     bool empty();
     unsigned long size();
-    void push(int *samples, unsigned long nSamples);
+    void push(int* samples, unsigned long nSamples);
     std::vector<int> pop(unsigned long nSamples);
 
     void signalEndOfStream();
-    void waitForNewElements(std::unique_lock<std::mutex> &lock);
+    void waitForNewElements(std::unique_lock<std::mutex>& lock);
     bool hasStreamEnded();
     std::mutex &syncMutex();
 
+private:
+    XOJ_TYPE_ATTRIB;
+
 protected:
     std::mutex queueLock;
     std::condition_variable lockCondition;
     bool streamEnd = false;
     bool notified = false;
-    XOJ_TYPE_ATTRIB;
 };
 
 
diff --git a/src/util/audio/AudioRecorder.cpp b/src/util/audio/AudioRecorder.cpp
index bd571973..9046a3b5 100644
--- a/src/util/audio/AudioRecorder.cpp
+++ b/src/util/audio/AudioRecorder.cpp
@@ -2,7 +2,8 @@
 
 #include "AudioRecorder.h"
 
-AudioRecorder::AudioRecorder(Settings *settings) : settings(settings)
+AudioRecorder::AudioRecorder(Settings* settings)
+ : settings(settings)
 {
     XOJ_INIT_TYPE(AudioRecorder);
 
@@ -51,4 +52,4 @@ void AudioRecorder::stop()
 
     // Reset the queue for the next recording
     this->audioQueue->reset();
-}
\ No newline at end of file
+}
diff --git a/src/util/audio/AudioRecorder.h b/src/util/audio/AudioRecorder.h
index 4d6b71e2..5534b33d 100644
--- a/src/util/audio/AudioRecorder.h
+++ b/src/util/audio/AudioRecorder.h
@@ -22,20 +22,22 @@
 class AudioRecorder
 {
 public:
-    explicit AudioRecorder(Settings *settings);
+    explicit AudioRecorder(Settings* settings);
     ~AudioRecorder();
+
+public:
     void start(std::string filename);
     void stop();
 
+private:
+    XOJ_TYPE_ATTRIB;
+
 protected:
     Settings* settings;
 
-    AudioQueue *audioQueue;
-    PortAudioProducer *portAudioProducer;
-    SoxConsumer *soxConsumer;
-
-private:
-    XOJ_TYPE_ATTRIB;
+    AudioQueue* audioQueue;
+    PortAudioProducer* portAudioProducer;
+    SoxConsumer* soxConsumer;
 };
 
 
diff --git a/src/util/audio/PortAudioProducer.cpp b/src/util/audio/PortAudioProducer.cpp
index e5d73d55..1d378fe0 100644
--- a/src/util/audio/PortAudioProducer.cpp
+++ b/src/util/audio/PortAudioProducer.cpp
@@ -38,10 +38,11 @@ std::list<DeviceInfo> PortAudioProducer::getInputDevices()
 
 const DeviceInfo PortAudioProducer::getSelectedInputDevice()
 {
+    XOJ_CHECK_TYPE(PortAudioProducer);
+
     return DeviceInfo(&sys.deviceByIndex(this->selectedInputDevice), true);
 }
 
-
 void PortAudioProducer::setInputDevice(DeviceInfo deviceInfo)
 {
     XOJ_CHECK_TYPE(PortAudioProducer);
@@ -80,7 +81,7 @@ void PortAudioProducer::startRecording()
     this->inputStream->start();
 }
 
-int PortAudioProducer::recordCallback(const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo *timeInfo,
+int PortAudioProducer::recordCallback(const void* inputBuffer, void* outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo* timeInfo,
                                       PaStreamCallbackFlags statusFlags)
 {
     XOJ_CHECK_TYPE(PortAudioProducer);
@@ -117,4 +118,4 @@ void PortAudioProducer::stopRecording()
     // Allow new recording by removing the old one
     delete this->inputStream;
     this->inputStream = nullptr;
-}
\ No newline at end of file
+}
diff --git a/src/util/audio/PortAudioProducer.h b/src/util/audio/PortAudioProducer.h
index 39a8833e..a0dff096 100644
--- a/src/util/audio/PortAudioProducer.h
+++ b/src/util/audio/PortAudioProducer.h
@@ -26,37 +26,33 @@ class PortAudioProducer
 {
 public:
     explicit PortAudioProducer(Settings *settings, AudioQueue *audioQueue);
-
     ~PortAudioProducer();
 
+public:
     std::list<DeviceInfo> getInputDevices();
-
     const DeviceInfo getSelectedInputDevice();
-
     void setInputDevice(DeviceInfo deviceInfo);
-
     bool isRecording();
-
     void startRecording();
+    int recordCallback(const void* inputBuffer, void* outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo* timeInfo, PaStreamCallbackFlags statusFlags);
+    void stopRecording();
 
-    int recordCallback(const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo * timeInfo, PaStreamCallbackFlags statusFlags);
+private:
+    XOJ_TYPE_ATTRIB;
 
-    void stopRecording();
 protected:
     double sampleRate = 44100.0;
     const unsigned long framesPerBuffer = 64;
 
     portaudio::AutoSystem autoSys;
-    portaudio::System &sys;
-    Settings *settings;
-    AudioQueue *audioQueue;
+    portaudio::System& sys;
+    Settings* settings;
+    AudioQueue* audioQueue;
 
-    PaDeviceIndex selectedInputDevice;
-    unsigned int inputChannels;
+    PaDeviceIndex selectedInputDevice = 0;
+    unsigned int inputChannels = 0;
 
-    portaudio::MemFunCallbackStream<PortAudioProducer> *inputStream = nullptr;
-private:
-    XOJ_TYPE_ATTRIB;
+    portaudio::MemFunCallbackStream<PortAudioProducer>* inputStream = nullptr;
 };
 
 
diff --git a/src/util/audio/SoxConsumer.cpp b/src/util/audio/SoxConsumer.cpp
index 37a3db64..76d20530 100644
--- a/src/util/audio/SoxConsumer.cpp
+++ b/src/util/audio/SoxConsumer.cpp
@@ -1,6 +1,7 @@
 #include "SoxConsumer.h"
 
-SoxConsumer::SoxConsumer(AudioQueue *audioQueue) : audioQueue(audioQueue)
+SoxConsumer::SoxConsumer(AudioQueue* audioQueue)
+ : audioQueue(audioQueue)
 {
     XOJ_INIT_TYPE(SoxConsumer);
 
@@ -18,11 +19,11 @@ SoxConsumer::~SoxConsumer()
     XOJ_RELEASE_TYPE(SoxConsumer);
 }
 
-void SoxConsumer::start(std::string filename, double sampleRate, const DeviceInfo &inputDevice)
+void SoxConsumer::start(std::string filename, double sampleRate, const DeviceInfo& inputDevice)
 {
     XOJ_CHECK_TYPE(SoxConsumer);
 
-    this->inputSignal = new sox_signalinfo_t;
+    this->inputSignal = new sox_signalinfo_t();
     this->inputSignal->rate = sampleRate;
     this->inputSignal->length = SOX_UNSPEC;
     this->inputSignal->channels = (unsigned int) inputDevice.getInputChannels();
@@ -46,7 +47,7 @@ void SoxConsumer::start(std::string filename, double sampleRate, const DeviceInf
 
                while (!audioQueue->empty())
                {
-                   std::vector<int> tmpBuffer  = audioQueue->pop(64ul * this->inputSignal->channels);
+                   std::vector<int> tmpBuffer = audioQueue->pop(64ul * this->inputSignal->channels);
 
                    if (!tmpBuffer.empty())
                    {
@@ -56,7 +57,6 @@ void SoxConsumer::start(std::string filename, double sampleRate, const DeviceInf
            }
 
            sox_close(this->outputFile);
-
        });
 }
 
@@ -84,5 +84,4 @@ void SoxConsumer::stop()
     {
         this->consumerThread->join();
     }
-
 }
diff --git a/src/util/audio/SoxConsumer.h b/src/util/audio/SoxConsumer.h
index 94b8b40c..37c267fe 100644
--- a/src/util/audio/SoxConsumer.h
+++ b/src/util/audio/SoxConsumer.h
@@ -27,20 +27,22 @@ class SoxConsumer
 public:
     explicit SoxConsumer(AudioQueue *audioQueue);
     ~SoxConsumer();
-    void start(std::string filename, double sampleRate, const DeviceInfo &inputDevice);
+
+public:
+    void start(std::string filename, double sampleRate, const DeviceInfo& inputDevice);
     void join();
     void stop();
 
-protected:protected:
-    sox_signalinfo_t *inputSignal = nullptr;
-    sox_format_t *outputFile = nullptr;
-    bool stopConsumer = false;
-
-    AudioQueue *audioQueue;
-    std::thread *consumerThread;
-
 private:
     XOJ_TYPE_ATTRIB;
+
+protected:
+    sox_signalinfo_t* inputSignal = nullptr;
+    sox_format_t* outputFile = nullptr;
+    bool stopConsumer = false;
+
+    AudioQueue* audioQueue;
+    std::thread* consumerThread = nullptr;
 };