Quantum Representations of Sound: From Mechanical Waves to Quantum Circuits

Abstract

By the time of writing, quantum audio still is a very young area of study, even within the quantum signal processing community. This chapter introduces the state of the art in quantum audio and discusses methods for the quantum representation of audio signals. Currently, no quantum representation strategy claims to be the best one for audio applications. Each one presents advantages and disadvantages. It can be argued that future quantum audio representation schemes will make use of multiple strategies aimed at specific applications. The authors also discuss ... . NOTE:This is an unedited abridged version of the pre-submission draft of a chapter, with the same title, published in the book Quantum Computer Music: Foundations, Methods and Advanced Concepts, by E. R. . Please refer to the version in this book for application examples and a discussion on sound synthesis methods based on quantum audio representation and their potential for developing new types of musical instruments.

The advent of quantum computer music: mapping the field

“…There is no such thing as a 'quantum random access memory' (QRAM) as yet. Even so, a few approaches for quantum audio representation have been proposed already [54]. Instead of storing the audio samples, methods are being developed to represent audio in terms of circuits.…”

“…Let us look closely at an approach to quantum audio representation, referred to as Quantum Probability Amplitude Modulation, or QPAM [54].…”

“…The ability to represent audio quantumly paves the way for the development of quantum audio processors and sound synthesisers. Let us envisage an audio effect unit proposed by Paulo Itaboraí at ICCMR, referred to as Geiger counter fffect, which uses QPAM [54].…”

“…The latter includes QSM (Quantum State Modulation) and MQSM (Multichannel Quantum State Modulation). More information is available in [54].…”

“…Figure 44. Hypothetic audio, represented using seven samples.Reproduced from[54], with permission from Springer Nature.…”