“By the end of the fourth section, at around 34:00, a new element has become discernible, if not recognizable. Radigue deftly transforms the filtered noise of the section four into what sounds like overtone-rich, guttural Tibetan chants. The enigmatic sound builds, swells, and becomes dense but its source is never easily identifiable. The sound could be a processed tape loop of Tibetan monks but it could also be purely synthesized on the ARP using noise-modulated, heavily filtered
oscillators. At around 42:30 Radigue begins to process these sounds further in a way that is remarkable to hear as well as to see in a spectrogram. Using a filter - either manually or slowly swept by a low frequency oscillator - she shapes the “chant” sounds into graceful timbre glissandi. They appear unmistakably as yellow-orange arcs in Figure 9”. (Chuck Johnson, Empty Music: Eliane Radigue’s L’Ile re-sonante, a spectral analysis)