I am searching for way to add custom sounds to minecraft without deleting it's original content and without using any mods. I watched a lot of tutorials but they are not working. They are saying that i need create folder custom in sounds folder which is in there. It appears that on all versions of minecraft code is same. I tried muliple of times. With whitespaces then without them.

Update: No warning is in logs but i don't hear any sound

Sound files format : ".ogg"
sounds,json (Tried with dots ] does not work) :

{ "custom.robotvoicestatus":{
"category": "voice",
"sounds": [ {
"name": "custom/robotvoicestatus", "stream": true
}]
},
"custom.robotvoicestatus2":{
"category": "voice",
"sounds": [ {
"name": "custom/robotvoicestatus2", "stream": true
}]
},
"custom.robotvoicewarning": {
"category": "voice",
"sounds": [ {
"name": "custom/robotvoicewarning", "stream": true
}]
},
"custom.robotvoicewelcome": {
"category": "voice",
"sounds": [ { "name": "custom/robotvoicewelcome", "stream": true
}]
}
}

Resource pack is on and path is assets/minecraft/sounds/custom. Files are in folder custom.

Emm.. help please. I am searched it. Whole day.