What is the fine-grained topic of the following text: Through the whole of Ask The Dust, Ortega experiments with complex textures and haunting soundscapes which are then painstakingly layered into dense formations, but, whilst the sounds themselves appear particularly intense, the resulting constructions, far from sounding lush and abundant, for the most part appear somewhat desolate and minimal. Only return the topic.
Ortega's experimental sound techniques in "Ask The Dust".