How to avoid reflection of two array which holds the same objects?

I'm having two arrays of same objects,

var callHistory = [{"CallId":1,"Note":"abcdefghijklmnop"}, {"CallId":2,"Note":"123343"}, {"CallId":3,"Note":"abc123"}];
var tempHistory = [{"CallId":1,"Note":"abcdefghijklmnop"}, {"CallId":2,"Note":"123343"}, {"CallId":3,"Note":"abc123"}];

for(var i = 0; i < tempHistory .length; i++)
{
    var callNote = tempHistory [i]["Note"];
    if(callNote.length > 6)
    {
        callNote = callNote.slice(0, 5);
        tempHistory [i]["Note"] = callNote;
    }
}

Here i'm changing the Note value of tempHistory array of index 0, but i'm getting the reflected response on callHistory also.

After the end of for loop.

callHistory = [{"CallId":1,"Note":"abcdef"}, {"CallId":2,"Note":"123343"}, {"CallId":3,"Note":"abc123"}];
tempHistory = [{"CallId":1,"Note":"abcdef"}, {"CallId":2,"Note":"123343"}, {"CallId":3,"Note":"abc123"}];

How it is getting refelcted and is there anyway to stop those kind reflection.