Sound for music technology: An introduction
Sound for music technology: An introduction

This free course is available to start right now. Review the full course description and key learning outcomes and create an account and enrol if you want a free statement of participation.

Free course

Sound for music technology: An introduction

2 Sinusoidal pressure waves

2.1 The importance of sine waves

For much of the rest of this unit we shall be concerned with the properties of a type of sound wave that when represented as a graph has a characteristic shape known as a sine wave. Figure 1 shows you what a sine-wave graph looks like. For the moment you need not be concerned with what this graph represents.

Figure 1
Figure 1 A sine wave

Despite their theoretical importance, sine waves are of limited use in the actual business of creating music – at least music of conventional kinds. Few instruments, for instance, produce a sine-wave type of sound when played in the normal way, although in electronic music sine waves can be a basic component of synthesised sounds.

Because pure sine-wave sounds are not often heard in music, I ought to begin this study by giving a few reasons why they are so important. One reason has already been hinted at in my reference to electronic synthesis. For our purposes sine waves are important for three main reasons:

  1. They can be used to define some basic terms and quantities relating to sound of all kinds. They therefore give us a basic vocabulary for talking about the physical properties of sound.

  2. They allow us to explore the relationships between the purely physical properties of sound and the subjective experience of hearing it.

  3. They are fundamental to the analysis and synthesis of sounds that are used musically (and also non-musically).

In this unit I will focus on the first two reasons.

Sine waves are fundamental in many areas of mathematics, science and technology, not just in sound. Many of the properties of sine waves, which I shall discuss later in this unit, are therefore of wider application than sound, although I shall not be referring to these other applications to any significant extent. However, before I can say anything further about sine waves, I need to prepare the ground by discussing pressure waves.


Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to university level study, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus