There are some sounds that are clearly different in waveform when recorded with a microphone, but when listened to with the ear, it is difficult to notice the difference.

• What kind of sound is it (or can it be made artificially)?
• What is the mechanism that prevents you from noticing the difference?
  • Is this the limit of my hearing?
  • Is the ear receiving the sound but creating an illusion in its later stages of brain processing?

Information Hiding, Digital Watermarking, Steganography

• Create sounds with embedding subliminal digital information. Embedded Information is detectable by machine microphone while human can’t notice it.
• Sound Enrichment, Side-channel.
• Information Security and Privacy.

Machine aided Sound Liveness Identification

• Due to the development of sound synthesis technology, it is not possible for the human ear to distinguish artificial spoofing of natural sounds.
• We need to develop a technique to detect artificial spoofing of natural sounds and to identify the liveness of the natural sounds.