image uploads but mp3 won't

<form action="upload.php"
enctype="multipart/form-data" method="post">
<p>
Please select image<br>
<input type="file" name="image" size="40">
</p>
<p>
Please select audio<br>
<input type="file" name="audio" size="40">
</p>

// checking image
if (($_FILES["image"]["type"] == "image/gif")
or ($_FILES["image"]["type"] == "image/jpeg")
or ($_FILES["image"]["type"] == "image/pjpeg")
or ($_FILES["image"]["type"] == "image/png"))
{
    if ($_FILES["image"]["error"] == 0)
    {
        move_uploaded_file($_FILES["image"]["tmp_name"], 
        "upload/".$_FILES["image"]["name"]);
        
    }
    else
    {
        echo "image upload failed";
    }
}
else
{
    echo "file is not supported image";
    
}
    
// checking mp3
if (substr($_FILES["audio"]["name"],-3) == "mp3")
{
    if ($_FILES["audio"]["error"] == 0)
    {
        move_uploaded_file($_FILES["audio"]["tmp_name"], 
        "upload/".$_FILES["audio"]["name"]);
    }
    else
    {
        echo "audio upload failed";
    }
}
else
{
    echo "file is not supported audio";
    
}

Old;
if ($_FILES["audio"]["error"] == 0)

New:
if ($_FILES["audio"]["error"] === false)