diff --git a/src/emu/sound/t6w28.c b/src/emu/sound/t6w28.c
index e42899dbae1..9f5d52cdc21 100644
--- a/src/emu/sound/t6w28.c
+++ b/src/emu/sound/t6w28.c
@@ -233,11 +233,19 @@ void t6w28_device::sound_stream_update(sound_stream &stream, stream_sample_t **i
 			left -= nextevent;
 		} while (left > 0);
 
-		out0 = vol[4] * m_volume[4] + vol[5] * m_volume[5] +
-				vol[6] * m_volume[6] + vol[3] * m_volume[7];
+		if (m_enabled)
+		{
+			out0 = vol[4] * m_volume[4] + vol[5] * m_volume[5] +
+					vol[6] * m_volume[6] + vol[3] * m_volume[7];
 
-		out1 = vol[4] * m_volume[0] + vol[5] * m_volume[1] +
-				vol[6] * m_volume[2] + vol[3] * m_volume[3];
+			out1 = vol[4] * m_volume[0] + vol[5] * m_volume[1] +
+					vol[6] * m_volume[2] + vol[3] * m_volume[3];
+		}
+		else
+		{
+			out0 = 0;
+			out1 = 0;
+		}
 
 		if (out0 > MAX_OUTPUT * STEP) out0 = MAX_OUTPUT * STEP;
 		if (out1 > MAX_OUTPUT * STEP) out1 = MAX_OUTPUT * STEP;
@@ -328,6 +336,13 @@ void t6w28_device::device_start()
 	save_item(NAME(m_period));
 	save_item(NAME(m_count));
 	save_item(NAME(m_output));
+	save_item(NAME(m_enabled));
+}
+
+
+void t6w28_device::set_enable(bool enable)
+{
+	m_enabled = enable;
 }
 
 const device_type T6W28 = &device_creator<t6w28_device>;
diff --git a/src/emu/sound/t6w28.h b/src/emu/sound/t6w28.h
index fad31b48f2a..10d99148bf3 100644
--- a/src/emu/sound/t6w28.h
+++ b/src/emu/sound/t6w28.h
@@ -10,6 +10,7 @@ public:
 	t6w28_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
 
 	DECLARE_WRITE8_MEMBER( write );
+	void set_enable( bool enable );
 
 protected:
 	// device-level overrides
@@ -35,6 +36,7 @@ private:
 	INT32 m_period[8];
 	INT32 m_count[8];
 	INT32 m_output[8];
+	bool m_enabled;
 };
 
 extern const device_type T6W28;
diff --git a/src/mess/drivers/ngp.c b/src/mess/drivers/ngp.c
index f8d16ec0fd6..915de98be98 100644
--- a/src/mess/drivers/ngp.c
+++ b/src/mess/drivers/ngp.c
@@ -256,8 +256,10 @@ WRITE8_MEMBER( ngp_state::ngp_io_w )
 		switch( data )
 		{
 		case 0x55:		/* Enabled sound */
+			m_t6w28->set_enable( true );
 			break;
 		case 0xAA:		/* Disable sound */
+			m_t6w28->set_enable( false );
 			break;
 		}
 		break;