Acousticophobia, or Phonophobia is a fear of loud sounds. It can also mean a fear of voices, or a fear of one's own voice. For example, listening to a CD that starts with a minute of silence and then suddenly goes into loud rock music would be extremely startling for most people, assuming they had no prior knowledge of the content of the CD. Being startled is in itself a normal reaction, but the key difference is that people with ligyrophobia actively fear such an occurrence.