PhD Thesis

Τhe study aims to provide useful insight for the acoustic design of jazz music auditoria. It seeks to scientifically investigate how acoustic quality is perceived when listening to jazz music, as well as the optimal reverberation time that enhances such listening experience. This is an experimental study and consists of two sets of experiments. 

The first set of experiments aimed to investigate the perception of acoustics during listening to recorded jazz music. Initially, using an experimental process there was compiled a list of thirty-three opposite-adjective pairs which are used frequently by jazz enthusiasts to describe the acoustic properties of jazz venues. These adjectives were employed at the poles of bipolar rating scales in an experiment aiming to investigate the perception of acoustics at recorded jazz concerts. The experimental data were analysed by factor analysis. Four independent factors were produced, namely, SMOOTHNESS, CLARITY, RICHNESS, PROXIMITY. Nineteen rating scales representative of these four factors were then selected, and a new perception experiment was carried out, during live concerts. Three independent factors were produced from analysis of the assessments, namely, CLARITY, SMOOTHNESS, PROXIMITY. 

These results demonstrate that there are common components in the perception of recorded and live jazz music. An additional experiment was carried out with musicians in jazz venues, aiming to investigate the perception of acoustics during performance. Analysis of the raw scale judgements produced three independent subjective factors, namely, NOISINESS, LIVENESS, SMOOTHNESS. This confirms the intuitive view that there are differences between listeners and performers regarding their acoustic perception.

The second set of experiments aimed to investigate the optimal reverberation time for jazz music listening. The process was based on the digital simulation of playing anechoic excerpts within a theoretical space, that provided the ability to adjust reverberation time in real-time (auralization). Experienced jazz listeners were asked to specify their preference for the values that optimise acoustic quality, using the three independent factors that were previously identified. 

Results indicated that preferred reverberation time was lower for jazz music than for classical music concerts, ranging between 0.6 s and 0.8 s, depending on the tempo, orchestration etc. In terms of spectral distribution, there was a preference for flat response between low and mid frequencies and an increase in the high frequency range.

Results from this research provide evidence on how jazz listeners perceive acoustic quality· also it is confirmed the need for a special approach to the design of jazz auditoria. Preference values for the reverberation time of such venues are identified, providing so guidelines for their design. 

https://www.didaktorika.gr/eadd/handle/10442/57948

(National Archive of PhD Theses - full text available for online reading or download)