throwing bad request Error when passing audio to API

[ratneshkumarcs]

Hi,
i am calling VoiceRequestTest and passing one of audio provided in sample but ti gives me error.
i am developing window form application.

error as below
{
"id": "e5cca5a5-53ba-4c1c-af16-2866096938b5",
"timestamp": "2018-08-08T00:46:08.31Z",
"lang": "en",
"status": {
"code": 400,
"errorType": "bad_request",
"errorDetails": "Invalid request content type, expecting "multipart/form-data" or "application/json; charset\u003dutf-8."
}
}