Achieving secured data transmission is not always an easy job. Secret data sharing requires confidentiality and Undetectability. Steganography is preferred than cryptography to achieve undetectability. Steganography hides the secret data inside the other file such as text, audio, video, so that the existence of the secret data is completely hidden. Recent research focuses much on utilizing Voice over Internet Protocol (VoIP) calls as a carrier for data hiding. VoIP calls are much preferred among internet users for its wide availability, dynamic time limit and low cost. This paper focuses on data hiding methods that uses VoIP as a carrier. The paper also analyzes the performance of the algorithms using the three metrics undetectability, bandwidth and robustness.