Worked at O.R.T.F. (French National Television), as a member of the Group of Musical Researches (G.R.M), under the leadership of Pierre Schaeffer (1963-70), contributed to Pierre Schaeffer’s book « Traité des Objets Musicaux » (1966), participated to the records realisation from « Solfège de l’Objet Sonore » by Pierre Schaeffer (1967) (one of two assistant composers allocated for the composition of the audio files). Since 1970 she is a free composer.. En 1975, Ferreyra is a member of the « Collège des Compositors » created by the G.M.E.B. Since 1967 she had commissions for concerts, festivals, film’s and TV music, theatre, video, write articles and gives seminaries and lectures, and had prizes till 1975. In 2014 she was elected as an Honour Member of the CIME/ICEM.