विसर्ग (visarga — "the letting go") is written as ः and pronounced as a voiceless breath: "aḥ". It appears at the end of most Sanskrit words — रामः (rāmaḥ — Rāma), देवः (devaḥ — god), नमः (namaḥ — salutation), सुखः (sukhaḥ — happiness). The visarga is not a vowel and not a true consonant. It is the echo of an ancient sound: many visargas come from original s or r at the end of words (rāmaḥ comes from proto-Sanskrit rāmas). The visarga's behaviour in sandhi completely depends on: (1) the vowel before it, and (2) the sound that follows. It can disappear, become ओ (o), turn into स् (s), or survive unchanged.