How to use curl request in Angular JS to get get audio file through api

My curl request is (It is working fine) :

curl -k -H "Authorization: Bearer " -H "ocp-apim-subscription-key: " -H "Accept-language: en-US" "https://api.api.ai/v1/tts?v=20150512&text=create+task+for+me" -o output.wav

My Angular Js code for above curl request (It is not working)

                    $http({
                        method: 'GET',
                        url: API_URL,
                        responseType: 'arraybuffer',
                        Headers: {
                            'Authorization': 'Bearer <my_access_token>',
                            'ocp-apim-subscription-key': '<my_key>',
                            'Accept-Language': 'en-US'},

                    }).success(function (data,status,headers,config) {


                        alert("Audio Result : " + data.byteLength);

                       // the success method called

                    }).error(function(data){
                       alert("Audio Error : "+JSON.stringify(data));
                   })

I need to get the output.wav file in the response but i only get the "Audio Result : 75 [or very according to data sent] " as an alert how i read the file from given server stream