You can assess a phone booth’s sound isolation before you see it in person. A laboratory report shows how the complete booth performs, and a common test standard lets you compare that performance across brands.
Our Elite-S achieved ISO 23351-1 Class A performance with 33 dB speech level reduction in testing by Intertek. A higher speech reduction rating means less speech sound escapes from the booth.
Elite-S keeps more speech sound inside. Compared with a booth rated at 30 dB (also Class A), its 33 dB speech reduction rating means about 50% less speech sound energy leaks out under the same ISO test conditions.
Understanding that difference also makes price comparisons fairer. Establish the acoustic performance first, then compare what each price includes.
Last Updated: October 5, 2026 | Author: Richard | Estimated Reading Time: 6 minutes
What does ISO 23351-1 measure?
Imagine someone making a call inside a booth with the door closed. You are standing outside. The question is how much the enclosure reduces the speech sound escaping into the surrounding space.
ISO 23351-1 provides a laboratory method for measuring speech level reduction by furniture ensembles and enclosures. For a phone booth, it lets buyers assess the complete enclosure rather than relying on a sound rating for one wall panel or a piece of glass.
The result is called speech level reduction. A higher value means greater reduction on this measure. Because different manufacturers can use the same method, you have a common basis for comparing their results.
The 33 dB figure describes how much the enclosure reduces speech escaping into the surrounding space. It is a reduction rating, rather than the noise level remaining inside the booth or a separate measurement of outside noise entering it.
For a useful comparison, look for ISO 23351-1 speech level reduction for the complete booth.
Why 33 dB is a meaningful step above 30 dB
Decibels use a logarithmic scale. Improving a booth’s speech reduction rating from 30 to 33 dB corresponds to an additional reduction of approximately 50% in the speech sound power escaping from it, under the same test conditions.
Il Canadian Centre for Occupational Health and Safety explains this logarithmic relationship. To compare three booth ratings, start with a booth rated for 28 dB of speech reduction. Set the speech sound power escaping from that booth to 100 relative units:
| Booth’s ISO speech reduction rating | Relative transmitted speech sound power — lower is better |
|---|---|
| Booth rated at 28 dB (reference) | 100 |
| Booth rated at 30 dB | About 63 |
| Elite-S: 33 dB | About 32 |
All three rows use the same reference speech source and weighted sound-power measure. The speech sound power transmitted by the 28 dB-rated booth is the common baseline of 100.
In this comparison, about 50% less speech sound power escapes from Elite-S than from the booth rated at 30 dB, and about 68% less than from the booth rated at 28 dB. Less escaping speech sound power means stronger speech isolation on this measure.
A 50% reduction in sound power does not mean a 50% reduction in perceived loudness. Your listening experience also depends on the surrounding background sound and your position. The 3 dB difference gives you a clear, measurable improvement in speech isolation under the same test method.
What Elite-S’s Class A result tells you
Le nostre Elite-S phone booth combines ISO 23351-1 Class A performance with Riduzione del livello del parlato di 33 dB. Read those together: the class gives the performance category, while the number gives the measured reduction within it.
Two products can share a class without having identical results. If you are choosing for acoustic performance, compare the actual speech reduction values as well as the class label.
We can provide the Elite-S Intertek report for your comparison. Match it with the model and configuration on your quotation, and use the same approach when reviewing another supplier’s booth.
Who is Intertek, and why does the laboratory matter?
Intertek is an international testing, inspection, and certification company with more than 140 years of history and a network spanning 100 countries. Its services include acoustical testing and consulting, giving buyers access to measured product performance from an established third party.
Intertek tested our Elite-S under ISO 23351-1 and measured 33 dB speech level reduction. The standard supplies the common method; the Intertek report documents our booth’s result. You can use that result to compare Elite-S with other booths tested to the same standard before visiting a showroom.
Compare acoustic performance before comparing prices
A booth rated for 28 dB of ISO speech reduction and our Elite-S rated at 33 dB offer different acoustic performance. Treating them as equivalent because both are enclosed phone booths overlooks an extra 5 dB of speech reduction.
Under the standardized comparison above, the booth rated at 28 dB transmits approximately 3.16 times as much speech sound power as Elite-S, rated at 33 dB. If you want Elite-S’s level of speech isolation, a cheaper 28 dB-rated booth represents a lower-performance option, not an equivalent product at a better price.
For a fair price comparison, shortlist booths with the same or similar ISO speech level reduction, then compare their configurations and delivered costs. Look at the numerical results, not just a shared class or the word “soundproof.”
This puts the price difference in context: you can see what acoustic performance your budget buys.
Why a higher price does not always mean better soundproofing
The sales route also affects what you pay. A purchase through importers, distributors, and local dealers can include margins and services at several stages. A higher retail price alone cannot tell you whether the enclosure reduces speech more effectively.
At B&H, we sell directly from our factory to you, without an intermediary dealer. You get Elite-S’s independently tested 33 dB speech reduction without the additional dealer markup. That combination of measured acoustic performance and direct pricing is central to the value we offer.
Our explanation of how factory-direct pricing can reduce office pod costs covers the channel differences in more detail.
Save on installation with modular self-assembly
We designed Elite-S with a modular structure to make it easier for you to assemble the booth yourself and save the cost of hiring an installer. Follow the assembly instructions and arrange the people and equipment needed for the job.
We supply our booths on a DDP (reso sdoganato) basis. Installation is separate: we do not provide installation services or installation quotations.
If you prefer professional installation, we can help you find a third-party installation company, which provides its own quotation. When comparing a dealer’s installed package with our DDP price, add the third-party installation cost if you plan to use that service.
Can a nearby showroom help you decide?
Yes. Visiting a nearby booth supplier can help you understand the space, door, ventilation, and experience of speaking inside an enclosure. To explore speech escaping from the booth, have someone speak inside with the door closed while you listen outside.
Then ask: “What is the ISO 23351-1 speech level reduction for this exact model?” Get the report so you can compare its result with Elite-S’s 33 dB.
If the comparable ISO result is below 33 dB, that booth achieved less speech reduction than Elite-S in the standardized test. A nearby visit gives you a useful feel for using a booth; the reports give you the numerical comparison across brands, even when the showrooms have different background sound levels.
Elite-S’s Intertek report gives you a firm basis for judging its speech isolation before seeing the booth in person. From there, focus on the design you like, the space you have, and the comfort you need. Explore our one-person office phone booths with the acoustic result and DDP price side by side, so you can choose with a clear understanding of both performance and value.
