Online Guide to Room Acoustics for Musicians
Online Guide to Room Acoustics for Musicians
Interactive Project Report
Published: December 18, 2023
Authors
Malte Kob (Hochschule für Musik Detmold) [PI], Martha de Francisco (McGill University), Fabien Lévy (Hochschule für Musik und Theater Leipzig), Kit Soden (Université de Montréal), and Caroline Traube (Université de Montréal)
This project spurred the development of an internet-based guide for musicians that describes, in layperson terms, the fundamentals of acoustic features of musical instruments, stages, and performance/rehearsal rooms using visual and auditory examples. The guide also aims to explain what and how parameters can be assessed along with the audio recordings to document a musical performance.
In honour of the 200th anniversary of Hermann von Helmholtz, the famous Helmholtz resonator effect was taken as an exemplary entry for the online guide and processed from a series of videos to the underlying physical principle. Since the Helmholtz effect is present in diverse sound sources such as the double bass, a blown bottle, and the deep booming inside a car with an open window, a common approach was followed to derive a uniform physical interpretation based upon these different occurrences in daily life. For each of these examples a short video was created.
This project’s output has been integrated into the online framework wiki.audio, which boosts its visibility to users beyond ACTOR . The wiki.audio community comprises teachers, students, and members of non-profit organizations including German Acoustical Society (DEGA), Verband Deutscher Tonmeister (VDT), Audio Engineering Society Germany (AES Germany). The full entry for Helmholtz resonators is available here: https://wiki.audio/En/0051
Example 1: A flickering candle flame in front of a double bass f-hole. The candle flickers due to the interaction between the resonant frequencies of the f-hole and the air vibrations produced by the instrument's sound waves.
Figure 2: When you take a bottle, and blow over the open neck, you hear a sound—that's the resonant frequency of the bottle. If you fill the bottle (or empty it) with a liquid, you will hear the frequency shift: the fuller the bottle (smaller volume), the higher the frequency.
Figure 3: The booming sound you hear when opening a car window is a result of the interaction between the airflow around the car and the cabin's resonant frequency.