Acoustic Auralisation of the Auditorium

Overview

This interactive application allows users to listen to how different audio signals (e.g., speech, music, or individual musical instruments) are perceived from different listening positions within the auditorium. Users can select one of the available audio samples or upload their own audio file, in order to hear how it would sound if it were played from the stage while the listener is seated at a specific position in the hall.

To capture the acoustic behaviour of the auditorium, an omnidirectional dodecahedral loudspeaker was placed on the stage, and Impulse Response measurements were carried out at multiple listening positions throughout the space. Different audio samples were then convolved with the corresponding impulse responses, enabling the reproduction of how these sounds would be perceived from each listening position.

In the present implementation, distance attenuation from the sound source was not included, in order to focus the study primarily on the effects of reverberation and the frequency response of the room on the perceived quality of sound.

Clarity Index (C80) – Heatmaps

The Clarity index (C80) describes how clearly a sound is perceived within a space. It is based on the relationship between the direct sound that reaches the listener and the reflections produced by the room.

The heatmaps presented here illustrate the spatial distribution of clarity across the listening positions in the auditorium for three frequency bands:

• 60–600 Hz (low frequencies)
• 600–3000 Hz (mid frequencies)
• 3000–10000 Hz (high frequencies)

These visualizations show that the perceived clarity of sound can vary across different listening positions in the space, depending also on the spectral content of the audio signal.

Low frequencies (60–600 Hz)

This range includes elements such as bass or kick components in music. In certain positions within the auditorium, the rhythmic foundation of the sound may be reproduced more clearly than in others.

Mid frequencies (600–3000 Hz)

This region is particularly important for the intelligibility of human speech. Variations in clarity across the auditorium may therefore influence how clearly speech is perceived in situations such as lectures, presentations, or theatrical performances.

High frequencies (3000–10000 Hz)

This range contains fast transient characteristics of sound, such as instrument attacks or rapid rhythmic patterns. In many seating positions, a high degree of temporal clarity can be observed, which is especially important for musical genres with strong rhythmic elements.

Overall, the heatmaps provide a visual representation of how the acoustic experience changes throughout the auditorium, highlighting the relationship between listening position and the spectral characteristics of sound