“`html
The pipe organ, characterized by its robust wooden structure and majestic metal pipes, is a significant presence in concert halls and places of worship. Even when it’s silent, the organ influences the surrounding acoustic space.
Researcher Ashley Snow from the University of Washington is investigating how the world’s largest category of musical instruments impacts the acoustics of the concert halls they occupy.
“The main inquiry is: how much does the pipe organ enhance the acoustic environment? A further question is, to what extent does music shape this acoustic space, and how does the acoustic environment shape music?” Snow elaborated.
On November 20, Snow will share findings about the sympathetic resonance of pipe organs and its implications for concert hall acoustics during the online 187th Meeting of the Acoustical Society of America, taking place from November 18-22, 2024.
Snow believes that the pipe organ generates an auto-tune effect because its pipes vibrate in harmony with the frequencies they are designed to play. This could enrich the overall sound when musical groups perform in spaces featuring organs.
To conduct her research, a sine-sweep—a method involving the use of a sine-wave signal to stimulate a system—was played through loudspeakers directed at the organ pipes, with the response captured via microphones positioned at various locations. Data collection involved placing microphones both inside the pipes and around them during a musical event and a church service.
“I was quite elevated, carefully positioning a probe microphone into the pipes while trying not to make any noise or stumble,” Snow recounted.
Her experimental findings confirmed that sympathetic resonance takes place in organ pipes during musical events, speeches, and sounds at pitches that correlate with musical notes, with an increase in overall sound amplitude observed when the signal aligns with the resonance frequencies of one or more pipes.
The exploration into how these acoustic effects influence the quality of musical experiences for audience members is still underway. Snow aims to broaden this study by contrasting room acoustics in spaces with and without organs and by categorizing and mathematically representing the tuning techniques of various global instruments. “What about the resonance produced by a marimba, cymbals, or piano strings? Or the harmonic alignment of horns in an ensemble? Would their sounds differ if they were isolated from one another? For better or worse? I hope to provoke thought on these topics,” she expressed.
“`
