Advances in pod soundproofing verification
Framery Labs, a research unit within Framery, is constantly looking for ways to push the frontier in office pod technology.
This time, we want to share a concept for ensuring, “in field conditions”, that a pod is in a perfect acoustic condition.
Namely, soundproofing is a crucial component of an office pod. Its significance lies in two primary advantages:
- it maintains speech privacy by encapsulating the internal sound, thus preventing it from reaching the outside for anyone to hear or to be disturbed by, and
- it profides a distraction-free environment inside the pod by blocking the outside noise from permeating the pod.
Consequently, the importance of soundproofing strategies, particularly in the context of an office pod, cannot be overstated.
However, challenges with soundproofing can often arise due to installation errors or defects which develop during prolonged use. For instance, even an improperly installed or worn-out seal can result in a sound leak which, obviously, adversely affects soundproofing and, hence, one of the primary purposes of the pod.
There are standardized methods to measure the soundproofing of an installed pod, for example, the Speech Transmission Index (STI) measurement. However, conducting an STI measurement involves expensive, laboratory-grade equipment such as calibrated loudspeakers and precision microphones and could only be executed under lab conditions.
Therefore, no accessible, cost-effective and reasonably accurate means of confirming soundproofing performance after pod installation or during its use exists in a regular office setting, i.e. “on the field”.
Addressing this gap requires an innovative solution integrating ubiquitous equipment, such as a smartphone. With nearly every office pod installer and office employee carrying a smartphone—a device capable of both producing and recording sound waves—it presents an unprecedented opportunity to assess soundproofing accurately enough.
Recognizing that the human voice frequency is the primary sound type office pods aim to insulate, one can leverage smart devices to recreate these sound frequencies and analyze the produced sound. This can be done using:
- a phone and a Bluetooth speaker or
- just two phones.
The implementation of this method using two phones unfolds in several steps. Initially, one phone is placed inside the pod, and the other phone is positioned outside, both recording the ambient sound through their built-in microphones with the pod door open. Next, while keeping the pod door open, the phone inside the pod plays a frequency sweep using its loudspeaker. The outside phone then records the transmission of this frequency sweep. With the pod door still open, the outside phone reciprocally plays a frequency sweep that the inside phone records.
Following this, the pod door is closed, and both phones record the ambient sound level. The next steps mirror the previous ones, with the pod door now closed: the inside phone plays a frequency sweep which the outside phone records, and vice-versa.
By distinguishing the frequency sweep sounds from the ambient scoundscape, the effectiveness of the pod’s soundproofing can be evaluated with sufficient accuracy.
Also, this technique may be used to investigate if the pod leaks sound, by comparing the results with a known, correctly installed pod.
This procedure can be executed instantly post-installation or anytime thereafter by the customer, thus proving its convenience and accessibility. It can be implemented as a smartphone application or as an added feature in an existing application, providing a “Pass / Fail” or a grading system for quick understanding of the pod’s performance.
To accommodate the variability among different phone brands and models, the solution may incorporate a calibration process, ensuring the phones are functioning as required for these measurements. Furthermore, enhanced accuracy can be achieved by equipping the phones with external microphones and loudspeakers. Lastly, the two-phone method could extend to diagnose specific audio leak points and perform other relevant acoustic tests on office pods.
At Framery Labs, the described solution has been developed and evaluated as a proof-of-concept method for measuring pods’ acoustic performance, and Framery is currently assessing the most feasible way to make such a tool available for its certified installers.