diff --git a/src/mame/audio/n8080.c b/src/mame/audio/n8080.c
index cd69deb1ec6..c187b6d5f90 100644
--- a/src/mame/audio/n8080.c
+++ b/src/mame/audio/n8080.c
@@ -191,7 +191,7 @@ static void spacefev_sound_pins_changed( running_machine &machine )
 	}
 	if (changes & ((1 << 0x2) | (1 << 0x3) | (1 << 0x5)))
 	{
-		generic_pulse_irq_line(machine.device("audiocpu"), 0, 1);
+		generic_pulse_irq_line(machine.device("audiocpu"), 0, 2);
 	}
 }
 
@@ -216,7 +216,7 @@ static void sheriff_sound_pins_changed( running_machine &machine )
 	}
 	if (changes & ((1 << 0x2) | (1 << 0x3) | (1 << 0x5)))
 	{
-		generic_pulse_irq_line(machine.device("audiocpu"), 0, 1);
+		generic_pulse_irq_line(machine.device("audiocpu"), 0, 2);
 	}
 }
 
@@ -232,7 +232,7 @@ static void helifire_sound_pins_changed( running_machine &machine )
 
 	if (changes & (1 << 6))
 	{
-		generic_pulse_irq_line(machine.device("audiocpu"), 0, 1);
+		generic_pulse_irq_line(machine.device("audiocpu"), 0, 2);
 	}
 }