In 1877, the first listeners to Edison’s acoustic phonograph felt that the sounds it reproduced were indistinguishable from real life. If we listen to those recordings now however, they sound incredibly crude. In his book, ‘Mastering Audio’, celebrated mastering engineer Bob Katz explains that this is because appreciation of sound is a learned experience. The more we experience, the more we learn, and thus we are able to ‘train’ our ears to develop an ever-greater appreciation of the subtleties of sonic and musical reproduction. Katz outlines two kinds of audio ear training; passive and hands-on. Passive ear training occurs all the time, provided that we are consciously aware of the sounds going on around us. We can practice identifying the characteristics of those sounds (“that PA sounds boomy”, “the reverb in this hall has a metallic ring to it”) and it will increase our ability to discriminate fine sonic differences. Hands-on ear training is the structured process of connecting audio techniques with the sound you have in your head. This is a skill, and like all skills it requires practice if you are to improve. In the world of classical music, it has long been recognised that ear training is a fundamental component of a thorough musical education. The Associated Board of the Royal Schools of Music (ABRSM) has long been the UK’s leading provider of music exams, and now offers assessments to over 600,000 music students every year worldwide. Aural (listening) tests have been a feature of their exams for many years. This is because the board believes that “listening lies at the heart of all good music-making. Developing aural awareness is fundamental to musical training because having a ‘musical ear’ impacts on all aspects of musicianship.” Since the turn of the millennium, producing music has become a much more common pursuit. The ever-decreasing price of digital music hardware and software has led to a boom in the number of mixing and mastering engineers. Ear training is as important to these practitioners as it is for the counterparts working in classical music, but to be effective, the training needs to take a slightly different form. Whereas the classical musician needs to be able to identify the intervals between notes, audio engineers need to be able to hear where on the frequency spectrum those notes fall. We can train ourselves to identify an incredibly wide range of audio properties. As well as learning to recognise specific frequency bands, we can learn to identify varying levels of compression, or to pinpoint the position of a sound in the stereo field. It has been recognised that audio engineers should be provided with an ear training curriculum that fits their needs, and in the last few years a number of dedicated ear-training tools have emerged. These tools have been developed to allow both aspiring and professional engineers to train their ears in a structured and holistic manner. SoundGym is one such tool, inviting users to “get advanced audio ear training, improve your listening skills and get better results in the studio.” The site provides an approachable and fun platform that has gamified the hands-on ear training process, the idea being that it is possible to have fun whilst also improving your ears!