Basically, wanting to write a sound that happens, a popping sound. Putting it in italics works, but there's one problem with it: my narrator and my main character go back and forth with each other, and when my MC speaks to my narrator, I have it in italics. I don't want people to initially think it's my MC saying it to the narrator, I want people to picture the sound. Here's an example of both the back-and-forth, and the sound. Let me know what you think. Mr. Frigo wasn't born on another planet, nor was he bitten by any animals. He certainly was not an eccentric millionaire, and he rarely got the girl. But let's not get ahead of ourselves. Our hero first needs to visit the mysterious address, where you've most likely already figured out was where his journey began. Dude, this is so boring. Just jump ahead to where I start kicking ass. As you wish, Mr. Frigo. And the sound: "What about you? Trying to be a hero?" The man now focused his attention on the clerk. Pop! Mr. Frigo watched in horror as the blood poured do— Wait, no. "What the hell? Is that bubble wrap?" Mr. Frigo's expression quickly went from being terrified to thoroughly confused. "Sir, that's not a real gun. I can see the orange on the tip." The clerk turned back around, unscathed, and finished stocking the cigarettes.
Something's not right. A loud sound then blood pouring down and the guy asks if it's bubble wrap?? A narrator wouldn't be cut off in mid-sentence. It will have to be described. ex. A loud pop! Mr. Frigo's expression went from terrified to confusion. (seems like it would be the other way around) A loud pop! Frigo's expression went from confusion to terrified as blood poured from the head of the clerk.
I guess I meant to put "Wait, no." (no quotes) in the next line, to mean that there wasn't actually any blood, it's just what the MC initially thought he'd look up to see.
I've seen style guides that recommend using onomatopoeia purely in standard text format. You are supposed to use onomatopoeia in verb form in standard text regardless, so the guide's recommendation that you avoid using italics or quotes for other cases is for the sake of consistent formatting. edit: actually, I misremembered. It was a person's recommendation that you use purely standard form because of the "verb as standard text" rule. Style guides just say to use consistent formatting for however you choose to do it. My bad.
Then there is something happening here that you need to describe better. Sounds in italics is fine. Pop! Pop! Pop! The gunfire caused the crowd to run in different directions. Screams and crying as mothers clutched their children's hands.
Why not put all of his speech in quotes, including when he's talking to the narrator? That would clear up any confusion about sounds in italics.
Limit the italics to the sounds. Please don't use them for dialogue. I won't respond further on the italics in dialogue debate, but italics are tremendously overused. They're as obnoxious as dozens exclamation marks in advertising copy.
Heh, sorry. I was still waking up when I wrote that. What I meant to say was why not put everything the MC says in quotes, including when he's speaking to the narrator, like you would normal dialogue? For example: Mr. Frigo wasn't born on another planet, nor was he bitten by any animals. He certainly was not an eccentric millionaire, and he rarely got the girl. But let's not get ahead of ourselves. Our hero first needs to visit the mysterious address, where you've most likely already figured out was where his journey began. "Dude, this is so boring. Just jump ahead to where I start kicking ass." As you wish, Mr. Frigo.
I would be disinclined to use an exclamation mark at the end of a sound. Exclamation marks look emotional, and loud sounds aren't. ~ Pop ~ POP Or something like that.
In an example like this I think you need the quotes to avoid confusion. But you have to admit there aren't that many novels that have the MC talk directly to the narrator.