How reusable is an Origami Impulse Source for reverberation time measurements?

What happens when the same Origami source is used again and again? 

This question is particularly relevant because the acoustic impulse is generated through the mechanical deformation of the folded paper structure. Because the acoustic impulse is generated through mechanical deformation of the folded paper structure, repeated use raises a practical question about the stability of the measurement results over time. Our study presented at FIA 2026 therefore focused specifically on the stability of reverberation time measurements after repeated reuse of the same Origami unit.  

Testing the same Origami source repeatedly 

The experimental campaign was designed to compare measurements made with the same Origami source before and after extensive repeated use. 

Measurements were performed in the Norsonic Media Room using two source positions and three receiver positions, resulting in six source-receiver configurations. Twenty valid repetitions were obtained for each configuration. 

The complete experiment included 240 Origami measurements, with 120 measurements in the initial campaign and another 120 in the final campaign. The initial and final measurements for identical source-receiver configurations were therefore separated by approximately 120 intermediate activations of the same Origami source.  

Reverberation times were evaluated using T20 in the frequency range from 250 Hz to 4 kHz. Measurements using swept-sine and interrupted-noise excitation were also performed in the same source and receiver positions to provide additional references.

What changed after repeated reuse? 

Very little for most of the measurement configurations. 

The mean absolute difference between the initial and final Origami campaigns was 0.036 s. 

Even more significantly, five of the six source-receiver configurations showed differences below 0.04 s after repeated use. The largest individual difference was 0.082 s, observed for one configuration.  

This is particularly interesting when the results are considered alongside the other measurement methods used in the experiment. The differences associated with repeated use of the Origami source were smaller than the differences observed between the Origami, swept-sine and interrupted-noise measurement methods themselves.  

In other words, within the conditions investigated, repeatedly using the same Origami unit introduced less variation than changing the measurement method. 

Measurement stability after repeated use 

Repeated activation naturally changes the folded paper structure, making measurement stability after repeated use an important aspect to investigate. 

Our measurements did not show an appreciable reuse effect over the number of activations investigated. Across the complete campaign, the Origami source maintained adequate measurement stability. 

The experiment covered a defined number of activations under specific measurement conditions. Within this range, the results demonstrate that repeated reuse of the same Origami unit did not appreciably affect the measured reverberation time. 

A lightweight and reusable impulse source 

Portability and simplicity are among the main advantages of impulsive reverberation time measurements. Unlike measurements requiring an amplified omnidirectional source, an Origami Impulse Source requires very little equipment at the measurement position. 

The results of this study add another practical consideration: reusability. 

For applications where an impulse source provides sufficient acoustic energy and dynamic range, the same Origami unit can be used repeatedly while maintaining stable results under the room conditions and range of reuse investigated in this study. 

The Origami Impulse Source is a portable, low-cost and reusable impulse source for reverberation time measurements. It complements Norsonic’s professional amplified sound-source solutions by providing a simple and practical option for room-acoustic surveys. Experimental testing across 240 measurements demonstrated stable reverberation time results within the investigated range of repeated use, with approximately 120 reuses separating the initial and final measurement campaigns. 

Learn more 

For a broader introduction to impulse-based reverberation time measurements, including the measurement principle, advantages, limitations and suitable applications, see our article Impulsive Method for Reverberation Time Measurement.  

The complete experimental methodology and results are presented in our FIA 2026 paper: 

“Evaluación de una fuente impulsiva tipo origami en la medición del tiempo de reverberación frente a métodos estandarizados” 
Jorge Páez, Erlend Berg and Berenice Campo. 

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