[matsi]

#include <amxmodx>
#include <fakemeta>

new g_die_sounds[][] =
{
    "player/die1.wav",
    "player/die2.wav",
    "player/die3.wav",
    "player/death6.wav"
};
    

public plugin_precache()
{
    register_plugin( "Block die sound", "1.0", "matsi" );
    register_forward( FM_EmitSound, "FwdEmitSound" );
}

public FwdEmitSound( const entity, const channel, const sound[], const Float:volume, const Float:attenuation, const flags, const pitch )
{
    for( new i; i < sizeof g_die_sounds; i ++ )
    {
        if( equal( sound, g_die_sounds[ i ] ) )
        return FMRES_SUPERCEDE;
    }
    return FMRES_IGNORED;
}

I'm not sure if thats the correct way to do it or if there are all the sounds you wanted to be blocked.

But try it.