If I'm adding sounds on resource packs where should sound.json go?

{
    "ak47_shot": {
        "sounds": [
            {
                "name": "custom/ak47_shot"
            } 
        ]
    },
    "ak47_reload": {
        "sounds": [
            {
                "name": "custom/ak47_reload"
            } 
        ]
    },
    "m79_shot": {
        "sounds": [
            {
                "name": "custom/m79_shot"
            } 
        ]
    },
    "m79_reload": {
        "sounds": [
            {
                "name": "custom/m79_reload"
            } 
        ]
    }
}

This is my sound.json file, and it doesn't work when I use /playsound custom.ak47_shot master @a I'm not sure there is a problem with sound.json, but I think there is a problem. Anyway, where should I put my sound.json file? I put it in myresourcepack/assets/minecraft/sounds.json right now. There is a myresourcepack/assets/minecraft/sounds folder too, and I putted my custom sounds in there.