diff --git a/LR35902/inc/Audio.h b/LR35902/inc/Audio.h
new file mode 100644
index 0000000..d9d983d
--- /dev/null
+++ b/LR35902/inc/Audio.h
@@ -0,0 +1,310 @@
+#pragma once
+
+#include <array>
+#include <memory>
+#include <iostream>
+#include <cassert>
+
+#include <Processor.h>
+
+namespace EightBit {
+	namespace GameBoy {
+
+		class Envelope {
+		public:
+			Envelope() {}
+
+			enum Direction { Attenuate, Amplify };
+
+			int default() const { return m_defaultValue; }
+			void setDefault(int value) { m_defaultValue = value; }
+
+			Direction direction() const { return (Direction)m_direction; }
+			void setDirection(int value) { m_direction = value; }
+			void setDirection(Direction value) { setDirection((int)value); }
+
+			int stepLength() const { return m_stepLength; }
+			void setStepLength(int value) { m_stepLength = value; }
+
+			void dump() const {
+				std::cout << "Envelope: default=" << default() << ",direction=" << direction() << ",step length=" << stepLength() << std::endl;
+			}
+
+		private:
+			int m_defaultValue;
+			int m_direction;
+			int m_stepLength;
+		};
+
+		class Sweep {
+		public:
+			Sweep() {}
+
+			enum Direction { Addition, Subtraction };
+
+			int time() const { return m_time; }
+			void setTime(int value) { m_time = value; }
+
+			Direction direction() const { return (Direction)m_direction; }
+			void setDirection(int value) { m_direction = value; }
+			void setDirection(Direction value) { setDirection((int)value); }
+
+			int shift() const { return m_shift; }
+			void setShift(int value) { m_shift = value; }
+
+			void dump() const {
+				std::cout << "Sweep: time=" << time() << ",direction=" << direction() << ",shift=" << shift() << std::endl;
+			}
+
+		private:
+			int m_time;
+			int m_direction;
+			int m_shift;
+		};
+
+		class AudioVoice {
+		public:
+			AudioVoice() {}
+
+			enum Type { Continuous, Counter };
+
+			Type type() const { return (Type)m_counterContinuous; }
+			void setType(int value) { m_counterContinuous = value; }
+			void setType(Type value) { setType((int)value); }
+
+			bool initialise() const { return !!m_initialise; }
+			void setInitialise(bool value) { m_initialise = value; }
+
+			virtual void dump() const {
+				std::cout << "Audio Voice: type=" << type() << ",initialise=" << initialise() << std::endl;
+			}
+
+		private:
+			int m_counterContinuous;
+			int m_initialise;
+		};
+
+		class WaveVoice : public AudioVoice {
+		public:
+			WaveVoice() {}
+
+			int frequencyLowOrder() const { return m_frequencyLowOrder; }
+
+			void setFrequencyLowOrder(int value) {
+				assert(value < Processor::Bit8);
+				m_frequencyLowOrder = value;
+			}
+
+			int frequencyHighOrder() const { return m_frequencyHighOrder; }
+
+			void setFrequencyHighOrder(int value) {
+				assert(value < Processor::Bit3);
+				m_frequencyHighOrder = value;
+			}
+
+			int frequency() const {
+				return (m_frequencyHighOrder >> 8) | m_frequencyLowOrder;
+			}
+
+			void setFrequency(int value) {
+				assert(value < Processor::Bit11);
+				m_frequencyHighOrder = (value >> 8) & Processor::Mask3;
+				m_frequencyLowOrder = value & Processor::Mask8;
+			}
+
+			virtual void dump() const override {
+				AudioVoice::dump();
+				std::cout << "Wave Voice: frequency=" << frequency() << std::endl;
+			}
+
+		private:
+			int m_frequencyLowOrder;	// 8 bits
+			int m_frequencyHighOrder;	// 3 bits
+		};
+
+		class RectangularVoice : public WaveVoice {
+		public:
+			RectangularVoice() {}
+
+			int waveFormDutyCycle() const { return m_waveFormDutyCycle; }
+			void setWaveFormDutyCycle(int value) { m_waveFormDutyCycle = value; }
+
+			int length() const { return m_soundLength; }
+			void setLength(int value) { m_soundLength = value; }
+
+			virtual void dump() const override {
+				WaveVoice::dump();
+				std::cout << "Rectangular Voice: wave form duty=" << waveFormDutyCycle() << ",length=" << length() << std::endl;
+			}
+
+		private:
+			int m_waveFormDutyCycle;
+			int m_soundLength;
+		};
+
+		// NR2X
+		class EnvelopedRectangularVoice : public RectangularVoice {
+		public:
+			EnvelopedRectangularVoice() {}
+
+			Envelope& envelope() { return m_envelope; }
+
+			virtual void dump() const override {
+				RectangularVoice::dump();
+				m_envelope.dump();
+			}
+
+		private:
+			Envelope m_envelope;
+		};
+
+		// NR1X
+		class SweptEnvelopedRectangularVoice : public EnvelopedRectangularVoice {
+		public:
+			SweptEnvelopedRectangularVoice() {}
+
+			Sweep& sweep() { return m_sweep; }
+
+			virtual void dump() const override {
+				EnvelopedRectangularVoice::dump();
+				m_sweep.dump();
+			}
+
+		private:
+			Sweep m_sweep;
+		};
+
+		// NR3X
+		class UserDefinedWaveVoice : public WaveVoice {
+		public:
+			UserDefinedWaveVoice() {}
+
+			bool enabled() const { return !!m_enabled; }
+			void setEnabled(bool value) { m_enabled = value; }
+				
+			int length() const { return m_soundLength; }
+			void setLength(int value) { m_soundLength = value; }
+
+			int level() const { return m_outputLevel; }
+			void setLevel(int value) { m_outputLevel = value; }
+
+			int packedWaveDatum(int i) const {
+				assert(i < 16);
+				return m_waveData[i];
+			}
+
+			void setPackedWaveDatum(int i, uint8_t value) {
+				assert(i < 16);
+				m_waveData[i] = value;
+			}
+
+			int waveDatum(int i) const {
+				assert(i < 32);
+				const auto packed = packedWaveDatum(i >> 1);
+				return i & 1 ? Processor::lowNibble(packed) : Processor::highNibble(packed);
+			}
+
+		private:
+			int m_enabled;
+			int m_soundLength;
+			int m_outputLevel;
+			std::array<uint8_t, 16> m_waveData;
+		};
+
+		// NR4X
+		class WhiteNoiseWaveVoice : public AudioVoice {
+		public:
+			WhiteNoiseWaveVoice() {}
+
+			Envelope& envelope() { return m_envelope;  }
+
+			int length() const { return m_soundLength; }
+			void setLength(int value) { m_soundLength = value; }
+
+			int polynomialShiftClockFrequency() const { return m_polynomialShiftClockFrequency; }
+			void setPolynomialShiftClockFrequency(int value) { m_polynomialShiftClockFrequency = value; }
+
+			int polynomialCounterSteps() const { return m_polynomialCounterSteps; }
+			void setPolynomialCounterSteps(int value) { m_polynomialCounterSteps = value; }
+
+			int frequencyDivisionRatio() const { return m_frequencyDivisionRatio; }
+			void setFrequencyDivisionRatio(int value) { m_frequencyDivisionRatio = value; }
+
+		private:
+			Envelope m_envelope;
+			int m_soundLength;
+			int m_polynomialShiftClockFrequency;
+			int m_polynomialCounterSteps;
+			int m_frequencyDivisionRatio;
+		};
+
+		class OutputChannel {
+		public:
+			OutputChannel() {}
+
+			bool vin() const { return m_vin; }
+			void setVin(bool value) { m_vin = value; }
+
+			int outputLevel() const { return m_outputLevel; }
+			void setOutputLevel(int value) { m_outputLevel = value; }
+
+			bool& outputVoice(int voice) { return m_outputVoice[voice]; }
+			bool& outputVoice1() { return m_outputVoice[0]; }
+			bool& outputVoice2() { return m_outputVoice[1]; }
+			bool& outputVoice3() { return m_outputVoice[2]; }
+			bool& outputVoice4() { return m_outputVoice[3]; }
+
+		private:
+			bool m_vin;
+			int m_outputLevel;
+			std::array<bool, 4> m_outputVoice;
+		};
+
+		class Audio {
+		public:
+			Audio() {
+				m_voices[0] = std::make_shared<SweptEnvelopedRectangularVoice>();
+				m_voices[1] = std::make_shared<EnvelopedRectangularVoice>();
+				m_voices[2] = std::make_shared<UserDefinedWaveVoice>();
+				m_voices[3] = std::make_shared<WhiteNoiseWaveVoice>();
+			}
+
+			std::shared_ptr<AudioVoice> voice(int i) { return m_voices[i]; }
+
+			SweptEnvelopedRectangularVoice* voice1() {
+				return (SweptEnvelopedRectangularVoice*)voice(0).get();
+			}
+
+			EnvelopedRectangularVoice* voice2() {
+				return (EnvelopedRectangularVoice*)voice(1).get();
+			}
+
+			UserDefinedWaveVoice* voice3() {
+				return (UserDefinedWaveVoice*)voice(2).get();
+			}
+
+			WhiteNoiseWaveVoice* voice4() {
+				return (WhiteNoiseWaveVoice*)voice(3).get();
+			}
+
+			OutputChannel& channel(int i) { return m_channels[i]; }
+			OutputChannel& channel1() { return channel(0); }
+			OutputChannel& channel2() { return channel(1); }
+
+			bool enabled() const { return m_enabled; }
+			void setEnabled(bool value) { m_enabled = value; }
+
+			void dump() const {
+				for (int i = 0; i < 4; ++i) {
+					std::cout << "** Voice " << i + 1 << std::endl;
+					m_voices[i]->dump();
+				}
+			}
+
+		private:
+			std::array<std::shared_ptr<AudioVoice>, 4> m_voices;
+			std::array<OutputChannel, 2> m_channels;
+			bool m_enabled;
+		};
+	}
+}
\ No newline at end of file
diff --git a/LR35902/inc/GameBoyBus.h b/LR35902/inc/GameBoyBus.h
index c1eaaa2..e983c81 100644
--- a/LR35902/inc/GameBoyBus.h
+++ b/LR35902/inc/GameBoyBus.h
@@ -9,6 +9,8 @@
 #include <Processor.h>
 #include <Signal.h>
 
+#include "Audio.h"
+
 namespace EightBit {
 	namespace GameBoy {
 		class Bus : public EightBit::Bus {
@@ -118,29 +120,7 @@ namespace EightBit {
 
 			Bus();
 
-			Signal<std::tuple<int, int>> Audio_SweepTimeModified;
-			Signal<std::tuple<int, int>> Audio_SweepDirectionModified;
-			Signal<std::tuple<int, int>> Audio_SweepShiftModified;
-			Signal<std::tuple<int, int>> Audio_WavePatternDutyModified;
-			Signal<std::tuple<int, int>> Audio_SoundLengthModified;
-			Signal<std::tuple<int, int>> Audio_DefaultEnvelopeVolumeModified;
-			Signal<std::tuple<int, int>> Audio_EnvelopeDirectionModified;
-			Signal<std::tuple<int, int>> Audio_EnvelopeStepLengthModified;
-			Signal<std::tuple<int, int>> Audio_FrequencyLoModified;
-			Signal<std::tuple<int, int>> Audio_InitialiseModified;
-			Signal<std::tuple<int, int>> Audio_CounterContinuousSelectionModified;
-			Signal<std::tuple<int, int>> Audio_FrequencyHiModified;
-			Signal<std::tuple<int, int>> Audio_SoundOnOffModified;
-			Signal<std::tuple<int, int>> Audio_OutputLevelModified;
-			Signal<std::tuple<int, int>> Audio_PolynomialShiftClockFrequencyModified;
-			Signal<std::tuple<int, int>> Audio_PolynomialCounterStepModified;
-			Signal<std::tuple<int, int>> Audio_FrequencyDivisionRatioModified;
-			Signal<std::tuple<int, int>> Audio_SO_VinOnOffModified;
-			Signal<std::tuple<int, int>> Audio_SO_OutputLevelModified;
-			Signal<std::tuple<int, int, int>> Audio_SO_SoundOutputModified;
-			Signal<int> Audio_AllSoundOnOffModified;
-			Signal<std::tuple<int, int>> Audio_ChannelOnOffModified;
-
+			Audio& audio() { return m_audio; }
 
 			void reset();
 
@@ -337,6 +317,8 @@ namespace EightBit {
 			bool m_p11;	// left/b
 			bool m_p10;	// right/a
 
+			Audio m_audio;
+
 			void checkTimer(int cycles);
 
 			void validateCartridgeType();
diff --git a/LR35902/src/GameBoyBus.cpp b/LR35902/src/GameBoyBus.cpp
index 164626e..5800d7e 100644
--- a/LR35902/src/GameBoyBus.cpp
+++ b/LR35902/src/GameBoyBus.cpp
@@ -246,120 +246,116 @@ void EightBit::GameBoy::Bus::Bus_WrittenByte(const uint16_t address) {
 			break;
 
 		case BASE + NR10:	// Sound mode 1 register: Sweep
-			Audio_SweepTimeModified.fire(std::make_tuple(1, (value >> 4) & Processor::Mask3));		// Bits 4-6
-			Audio_SweepDirectionModified.fire(std::make_tuple(1, (value >> 3) & Processor::Mask1));	// Bits 3
-			Audio_SweepShiftModified.fire(std::make_tuple(1, value & Processor::Mask3));			// Bits 0-2
+			audio().voice1()->sweep().setTime((value >> 4) & Processor::Mask3);			// Bits 4-6
+			audio().voice1()->sweep().setDirection((value >> 3) & Processor::Mask1);	// Bit 3
+			audio().voice1()->sweep().setShift(value & Processor::Mask3);				// Bits 0-2
 			break;
 
 		case BASE + NR11:	// Sound mode 1 register: Sound length / Wave pattern duty
-			Audio_WavePatternDutyModified.fire(std::make_tuple(1, (value >> 6) & Processor::Mask2));// Bits 6-7
-			Audio_SoundLengthModified.fire(std::make_tuple(1, value & Processor::Mask6));		// Bits 0-5
+			audio().voice1()->setWaveFormDutyCycle((value >> 6) & Processor::Mask2);	// Bits 6-7
+			audio().voice1()->setLength(value & Processor::Mask6);						// Bits 0-5
 			break;
 
 		case BASE + NR12:	// Sound mode 1 register: Envelope
-			Audio_DefaultEnvelopeVolumeModified.fire(std::make_tuple(1, (value >> 4) & Processor::Mask4));	// Bits 4-7
-			Audio_EnvelopeDirectionModified.fire(std::make_tuple(1, (value >> 3) & Processor::Mask1));		// Bits 3
-			Audio_EnvelopeStepLengthModified.fire(std::make_tuple(1, value & Processor::Mask3));					// Bits 0-2
+			audio().voice1()->envelope().setDefault((value >> 4) & Processor::Mask4);	// Bits 4-7
+			audio().voice1()->envelope().setDirection((value >> 3) & Processor::Mask1);		// Bit 3
+			audio().voice1()->envelope().setStepLength(value & Processor::Mask3); 			// Bits 0-2
 			break;
 
 		case BASE + NR13:	// Sound mode 1 register: Frequency lo
-			Audio_FrequencyLoModified.fire(std::make_tuple(1, value));
+			audio().voice1()->setFrequencyLowOrder(value);
 			break;
 
 		case BASE + NR14:	// Sound mode 1 register: Frequency hi
-			Audio_InitialiseModified.fire(std::make_tuple(1, (value >> 7) & Processor::Mask1));					// Bits 7
-			Audio_CounterContinuousSelectionModified.fire(std::make_tuple(1, (value >> 6) & Processor::Mask1));// Bits 6
-			Audio_FrequencyHiModified.fire(std::make_tuple(1, value & Processor::Mask3));						// Bits 0-2
+			audio().voice1()->setInitialise((value >> 7) & Processor::Mask1);	// Bits 7
+			audio().voice1()->setType((value >> 6) & Processor::Mask1);			// Bits 6
+			audio().voice1()->setFrequencyHighOrder(value & Processor::Mask3);	// Bits 0-2
 			break;
 
 		case BASE + NR21:	// Sound mode 2 register: Sound length / Wave pattern duty
-			Audio_WavePatternDutyModified.fire(std::make_tuple(2, (value >> 6) & Processor::Mask2));// Bits 6-7
-			Audio_SoundLengthModified.fire(std::make_tuple(2, Processor::Mask6));				// Bits 0-5
+			audio().voice2()->setWaveFormDutyCycle((value >> 6) & Processor::Mask2);	// Bits 6-7
+			audio().voice2()->setLength(value & Processor::Mask6);						// Bits 0-5
 			break;
 
 		case BASE + NR22:	// Sound mode 2 register: Envelope
-			Audio_DefaultEnvelopeVolumeModified.fire(std::make_tuple(2, (value >> 4) & Processor::Mask4));	// Bits 4-7
-			Audio_EnvelopeDirectionModified.fire(std::make_tuple(2, (value >> 3) & Processor::Mask1));		// Bits 3
-			Audio_EnvelopeStepLengthModified.fire(std::make_tuple(2, value & Processor::Mask3));					// Bits 0-2
+			audio().voice2()->envelope().setDefault((value >> 4) & Processor::Mask4);	// Bits 4-7
+			audio().voice2()->envelope().setDirection((value >> 3) & Processor::Mask1);		// Bit 3
+			audio().voice2()->envelope().setStepLength(value & Processor::Mask3); 			// Bits 0-2
 			break;
 
 		case BASE + NR23:	// Sound mode 2 register: Frequency lo
-			Audio_FrequencyLoModified.fire(std::make_tuple(2, value));
+			audio().voice2()->setFrequencyLowOrder(value);
 			break;
 
 		case BASE + NR24:	// Sound mode 2 register: Frequency hi
-			Audio_InitialiseModified.fire(std::make_tuple(2, (value >> 7) & Processor::Mask1));					// Bits 7
-			Audio_CounterContinuousSelectionModified.fire(std::make_tuple(2, (value >> 6) & Processor::Mask1));// Bits 6
-			Audio_FrequencyHiModified.fire(std::make_tuple(2, value & Processor::Mask3));						// Bits 0-2
+			audio().voice2()->setInitialise((value >> 7) & Processor::Mask1);	// Bit 7
+			audio().voice2()->setType((value >> 6) & Processor::Mask1);			// Bit 6
+			audio().voice2()->setFrequencyHighOrder(value & Processor::Mask3);	// Bits 0-2
 			break;
 
 		case BASE + NR30:	// Sound mode 3 register: Sound on/off
-			Audio_SoundOnOffModified.fire(std::make_tuple(3, (value >> 7) & Processor::Mask1));					// Bits 0-2
+			audio().voice3()->setEnabled((value >> 7) & Processor::Mask1);		// Bit 7
 			break;
 
 		case BASE + NR31:	// Sound mode 3 register: Sound length
-			Audio_SoundLengthModified.fire(std::make_tuple(3, value));
+			audio().voice3()->setLength(value);
 			break;
 
 		case BASE + NR32:	// Sound mode 3 register: Select output level
-			Audio_OutputLevelModified.fire(std::make_tuple(3, value));
+			audio().voice3()->setLevel(value);
 			break;
 
 		case BASE + NR33:	// Sound mode 3 register: Frequency lo
-			Audio_FrequencyLoModified.fire(std::make_tuple(3, value));
+			audio().voice3()->setFrequencyLowOrder(value);
 			break;
 
 		case BASE + NR34:	// Sound mode 3 register: Frequency hi
-			Audio_InitialiseModified.fire(std::make_tuple(3, (value >> 7) & Processor::Mask1));					// Bits 7
-			Audio_CounterContinuousSelectionModified.fire(std::make_tuple(3, (value >> 6) & Processor::Mask1));// Bits 6
-			Audio_FrequencyHiModified.fire(std::make_tuple(3, value & Processor::Mask3));						// Bits 0-2
+			audio().voice3()->setInitialise((value >> 7) & Processor::Mask1);	// Bits 7
+			audio().voice3()->setType((value >> 6) & Processor::Mask1);			// Bits 6
+			audio().voice3()->setFrequencyHighOrder(value & Processor::Mask3);	// Bits 0-2
 			break;
 
 		case BASE + NR41:	// Sound mode 4 register: Sound length
-			Audio_SoundLengthModified.fire(std::make_tuple(4, value & Processor::Mask6));	// Bits 0-5
+			audio().voice4()->setLength(value & Processor::Mask6);					// Bits 0-5
 			break;
 
 		case BASE + NR42:	// Sound mode 4 register: Envelope
-			Audio_DefaultEnvelopeVolumeModified.fire(std::make_tuple(4, (value >> 4) & Processor::Mask4));	// Bits 4-7
-			Audio_EnvelopeDirectionModified.fire(std::make_tuple(4, (value >> 3) & Processor::Mask1));		// Bits 3
-			Audio_EnvelopeStepLengthModified.fire(std::make_tuple(4, value & Processor::Mask3));					// Bits 0-2
+			audio().voice4()->envelope().setDefault((value >> 4) & Processor::Mask4);	// Bits 4-7
+			audio().voice4()->envelope().setDirection((value >> 3) & Processor::Mask1);		// Bit 3
+			audio().voice4()->envelope().setStepLength(value & Processor::Mask3); 			// Bits 0-2
 			break;
 
 		case BASE + NR43:	// Sound mode 4 register: Polynomial counter
-			Audio_PolynomialShiftClockFrequencyModified.fire(std::make_tuple(4, (value >> 4) & Processor::Mask4));	// Bits 4-7
-			Audio_PolynomialCounterStepModified.fire(std::make_tuple(4, (value >> 3) & Processor::Mask1));			// Bit 3
-			Audio_FrequencyDivisionRatioModified.fire(std::make_tuple(4, value & Processor::Mask3));				// Bits 0-2
+			audio().voice4()->setPolynomialShiftClockFrequency((value >> 4) & Processor::Mask4);	// Bits 4-7
+			audio().voice4()->setPolynomialCounterSteps((value >> 3) & Processor::Mask1);			// Bit 3
+			audio().voice4()->setFrequencyDivisionRatio(value & Processor::Mask3);					// Bits 0-2
 			break;
 
 		case BASE + NR44:	// Sound mode 4 register: counter/consecutive; inital
-			Audio_InitialiseModified.fire(std::make_tuple(4, (value >> 7) & Processor::Mask1));						// Bit 7
-			Audio_CounterContinuousSelectionModified.fire(std::make_tuple(4, (value >> 6) & Processor::Mask1));	// Bits 6
+			audio().voice4()->setInitialise((value >> 7) & Processor::Mask1);	// Bit 7
+			audio().voice4()->setType((value >> 6) & Processor::Mask1);			// Bit 6
 			break;
 
-		case BASE + NR50:	// Channel control/on-off/volume
-			Audio_SO_VinOnOffModified.fire(std::make_tuple(2, (value >> 7) & Processor::Mask1));					// Bit 7
-			Audio_SO_OutputLevelModified.fire(std::make_tuple(2, (value >> 4) & Processor::Mask3));					// Bits 4-6
-			Audio_SO_VinOnOffModified.fire(std::make_tuple(1, (value >> 3) & Processor::Mask1));					// Bit 3
-			Audio_SO_OutputLevelModified.fire(std::make_tuple(1, value & Processor::Mask3));						// Bits 0-2
+		case BASE + NR50:	// Channel control: on-off/volume
+			audio().channel2().setVin((value >> 7) & Processor::Mask1);			// Bit 7
+			audio().channel2().setOutputLevel((value >> 4) & Processor::Mask3);	// Bits 4-6
+			audio().channel1().setVin((value >> 3) & Processor::Mask1);			// Bit 3
+			audio().channel1().setOutputLevel(value & Processor::Mask3);		// Bits 0-2
 			break;
 
 		case BASE + NR51:
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(2, 4, (value >> 7) & Processor::Mask1));				// Bit 7
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(2, 3, (value >> 6) & Processor::Mask1));				// Bit 6
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(2, 2, (value >> 5) & Processor::Mask1));				// Bit 5
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(2, 1, (value >> 4) & Processor::Mask1));				// Bit 4
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(1, 4, (value >> 3) & Processor::Mask1));				// Bit 3
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(1, 3, (value >> 2) & Processor::Mask1));				// Bit 2
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(1, 2, (value >> 1) & Processor::Mask1));				// Bit 1
-			Audio_SO_SoundOutputModified.fire(std::make_tuple(1, 1, value & Processor::Mask1));						// Bit 0
+			audio().channel2().outputVoice4() = (value >> 7) & Processor::Mask1;	// Bit 7
+			audio().channel2().outputVoice3() = (value >> 6) & Processor::Mask1;	// Bit 6
+			audio().channel2().outputVoice2() = (value >> 5) & Processor::Mask1;	// Bit 5
+			audio().channel2().outputVoice1() = (value >> 4) & Processor::Mask1;	// Bit 4
+			audio().channel1().outputVoice4() = (value >> 3) & Processor::Mask1;	// Bit 3
+			audio().channel1().outputVoice3() = (value >> 2) & Processor::Mask1;	// Bit 2
+			audio().channel1().outputVoice2() = (value >> 1) & Processor::Mask1;	// Bit 1
+			audio().channel1().outputVoice1() = value & Processor::Mask1;			// Bit 0
 			break;
 
 		case BASE + NR52:	// Sound on/off
-			Audio_AllSoundOnOffModified.fire((value >> 7) & Processor::Mask1);						// Bit 7
-			Audio_ChannelOnOffModified.fire(std::make_tuple(4, (value >> 3) & Processor::Mask1));	// Bit 3
-			Audio_ChannelOnOffModified.fire(std::make_tuple(3, (value >> 2) & Processor::Mask1));	// Bit 2
-			Audio_ChannelOnOffModified.fire(std::make_tuple(2, (value >> 1) & Processor::Mask1));	// Bit 1
-			Audio_ChannelOnOffModified.fire(std::make_tuple(1, value & Processor::Mask1));			// Bit 0
+			audio().setEnabled((value >> 7) & Processor::Mask1);	// Bit 7
 			break;
 
 		case BASE + LCDC:
diff --git a/LR35902/src/LR35902.vcxproj b/LR35902/src/LR35902.vcxproj
index 141fb76..1838a19 100644
--- a/LR35902/src/LR35902.vcxproj
+++ b/LR35902/src/LR35902.vcxproj
@@ -140,6 +140,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClInclude Include="..\inc\AbstractColourPalette.h" />
+    <ClInclude Include="..\inc\Audio.h" />
     <ClInclude Include="..\inc\GameBoyBus.h" />
     <ClInclude Include="..\inc\CharacterDefinition.h" />
     <ClInclude Include="..\inc\Disassembler.h" />
diff --git a/LR35902/src/LR35902.vcxproj.filters b/LR35902/src/LR35902.vcxproj.filters
index ed7430e..200a16b 100644
--- a/LR35902/src/LR35902.vcxproj.filters
+++ b/LR35902/src/LR35902.vcxproj.filters
@@ -38,6 +38,9 @@
     <ClInclude Include="..\inc\ObjectAttribute.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\inc\Audio.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">
diff --git a/LR35902/src/stdafx.h b/LR35902/src/stdafx.h
index 831f62d..83e44c1 100644
--- a/LR35902/src/stdafx.h
+++ b/LR35902/src/stdafx.h
@@ -10,8 +10,11 @@
 #include <map>
 #include <bitset>
 #include <string>
+#include <tuple>
+#include <cassert>
 
 #include <algorithm>
+#include <memory>
 
 #include <iostream>
 #include <fstream>