The 18 Categories of Subjective Music Listening: Comparing Our Goals
The final evaluator is the listener. If we can make it sound better to the listener, then we are going in the right direction. The best way to make any side-by-side evaluation is by a matched set of specific goals. Each side can be compared with matched metrics and the results observed. How can we find a set of goals to use as a reference? Fortunately, one was provided for us by the esteemed acoustician Leo Beranek, when in 1962 he published Music Acoustics & Architecture. This groundbreaking book originated a set of evaluative criteria for concert hall performance. Beranek visited halls, measured their acoustic performance, and interviewed conductors and critics. The statistical data of 54 concert halls was compiled and a framework created that scored the hall performance in different categories. Concert halls, which were constructed hundreds of years ago, were evaluated side by side with those of the recent past, by the same measures. The conclusion at the time was that no single criterion could be found which would make a hall great, while certain key trends were required for success. The key factors were prioritized by degree of effect, since no two halls had identical parameters.
Eighteen categories of subjective perception were considered. Some of the categories were given numerical scoring weights, while others were found to be too interdependent to be assigned discrete values. These subjective measures were then compared with objective measures such as the room volume, reverb time, etc. The study correlated the subjective with the objective data and the result was a comprehensive assessment of the hall’s physical parameters to the listener’s experience. From that point forward, architectural acoustics moved ahead on a foundation of scientific data. It continues to refine the process further, even now. All of the 18 categories remain relevant to our current-day listening experience, whether it is natural sound or through speakers. This is not surprising, since little has changed in the way of human anatomy in the last century. Therefore, these metrics can be employed by audio engineers as well. If we can achieve the same subjective effect to a blindfolded listener, we have achieved an equivalent sonic experience. This is the core of the issue. The objective means for acousticians and audio engineers to achieve matched subjective results are very different. If we can relate these different means of achieving our common goals we will have found the translation guide we are seeking. Let’s begin by meeting Beranek’s subjective parameters (For more information purchase the book). These parameters are paraphrased and stripped of any specific reference to the symphonic experience. What follows are the 18 attributes described in terms that are independent of musical genre, venue or sound transmission method.
Subjective attributes of musical/acoustic quality:
1. Intimacy: this refers to the sonic perspective of the listeners. The desire is for listeners to experience a feeling of proximity to the music, as if we were listening in a small room. A lack of intimacy corresponds to a feeling of distance and separation as in a large room. 2. Liveness: this is experienced as a fullness of tone in the mid-range and high frequencies. 3. Warmth: a fullness of tone in the low frequencies. 4. Loudness of the direct sound: the desire is for the loudness to be appropriately scaled to the musical content. If too loud the experience is unpleasant, if too low the experience lacks the desired impact 5. Loudness of the reverberant sound: the desired effect is for the reverberation to have the appropriate mix of level and duration to provide additional loudness to the direct signal. An insufficient quantity will result in the overall experience lacking loudness, while excessive amounts will cause the opposite effect. 6. Definition, clarity: a clear and distinct sound. 7. Brilliance: bright, clear ringing sound, rich in harmonics. 8. Diffusion: the spatial aspect of reverberation is found here. Diffusion of the sound creates the experience of sound arriving from all directions. 9. Balance: this factor evaluates the relative levels of the instruments and voice. Good balance entails the instruments heard in their proper level perspectives. Poor balance is found when some instruments are favored over others. 10. Blend: good blending is perceived as a harmonious mix of the instruments. 11. Ensemble: this concerns how well the musicians can hear themselves. Good ensemble is obtained when the musicians can hear themselves well. 12. Immediacy of response: this is a measure of how well the musicians feel about the responsiveness of the sound. The goal is for the musicians to feel the sound and be able to adapt quickly enough to their changes so as not to disrupt them. 13. Texture: the fine grain of the listening experience. Texture is described in similar terms to the sense of touch. Music with fine texture has a richness and complexity to its outer surface. 14. Freedom from echo: the desired effect is that we do not hear discrete echoes. 15. Freedom from noise: the lowest amount of noise is desired. 16. Dynamic range: this is the range between the maximum level and the noise. The maximum level would be limited by comfort levels and the minimum by the ambient noise. 17. Tonal quality: rich tonal quality is free from the distortions of peaks and dips in the response over frequency. Poor tonal quality has an uneven frequency response that may cause certain notes to be lost and others to be unintentionally accentuated. 18. Uniformity: the extent to which we can create a similar experience for all listeners in the hall.
Excerpt from Sound Systems: Design and Optimization by Bob McCarthy.
About the Author
Bob McCarthy specializes in the sound system optimization and design as the president of Alignment & Design, Inc. He is the foremost educator in the field of sound system optimization and has conducted training courses worldwide for over twenty years. Bob’s clients have included esteemed companies such as Cirque Du Soleil and Walt Disney Entertainment, as well as, many of the world’s best sound designers, such as Jonathan Deans, Tony Meola, Andrew Bruce, and Tom Clark, among others.