Studies of Austronesian peoples have not paid much attention to the words said by the religious practitioners. This study of the invocations of both male and female religious officiants of the Puyuma shows how the “spirits’ language” possesses a perfect matrix. The form and rhythm help them memorize the invocations which they pronounce in short, rhythmic phrases: the melodic element of the tonality or the assonances and alliterations generate an acoustic wave. All these formulas, repeated daily, insure a relative automatism. The “language of the spirits” is certainly not the sum of unused ancient elements of contemporary language, even though the Puyuma say it is an “ancient language” which only spirits and officiants understand. Some words are probably words of the past more or less transformed and used only for their phonetic value. The “language of the spirits” is not a secret one. The fact that people are unaware of its meaning does not result from a prohibition but simply from ignorance even of the officiants and especially from the indifference of those who do no use it.