Python Machine Learning Cookbook - Second Edition

Reading and plotting audio data

Let's take a look at how to read an audio file and visualize the signal. This will be a good starting point, and it will give us a good understanding of the basic structure of audio signals. Before we start, we need to understand that audio files are digitized versions of actual audio signals. Actual audio signals are complex, continuous-valued waves. In order to save a digital version, we sample the signal and convert it into numbers. For example, speech is commonly sampled at 44,100 Hz. This means that each second of the signal is broken down into 44,100 parts, and the values at these timestamps are stored. In other words, you store a value every 1/44,100 seconds. As the sampling rate is high, we feel that ...