How to compare Silent Pod acoustic reports using ISO 23351-1

Two Silent Pod acoustic reports can show similar decibel figures while supporting different conclusions. A useful comparison starts with the measurement method, the tested enclosure, and its operating condition. Only then does the headline result become meaningful.

ISO 23351-1 provides a laboratory method for measuring the reduction of speech sound levels by furniture ensembles and enclosures. For office pods, it helps evaluate how effectively the complete enclosure reduces speech transmitted to the surrounding space. It does not, by itself, establish that conversations will be confidential in every office.

Start with the reported quantity, not the largest number

The central result to look for is speech level reduction, D_S,A, expressed in decibels. It describes the reduction of a standardized speech signal under the prescribed measurement conditions. A higher value indicates greater speech level reduction under that method.

Check that both reports explicitly identify ISO 23351-1 and report the same quantity. A brochure stating “30 dB sound insulation” is insufficient for comparison if it does not identify the measurement method or explain what the number represents.

Several acoustic figures can appear in a supplier’s documentation, but they answer different questions:

If one supplier provides a complete enclosure result and another provides only a glass certificate, the evidence is not equivalent. Do not rank those products by comparing their decibel numbers.

Check which Silent Pod was actually tested

An acoustic report applies to the specimen described in it. A shared product family name does not establish that every size, door arrangement, or ventilation package achieves the same result.

Match the report’s model identification to the proposed purchase. Then examine the specimen description, drawings, and photographs. Useful details include external dimensions, glazing arrangement, door construction, seals, ventilation openings, cable routes, and internal finishes.

These details matter because sound can travel through several routes at once. Strong wall construction cannot compensate indefinitely for leakage around a door or through an inadequately treated air passage. A change that looks minor on a sales drawing may alter the enclosure’s acoustic performance.

Pay particular attention when moving from a single-person call booth to a meeting pod. Different dimensions, panel spans, doors, and ventilation arrangements make simple extrapolation unreliable. A report for the smaller enclosure should not automatically become the evidence for a larger model.

Record any differences between the tested specimen and the supplied configuration. Where a supplier proposes an equivalent construction, request a documented technical basis that explains why the original result remains applicable.

Read the operating conditions before comparing results

A pod must provide ventilation while people use it. Its acoustic performance therefore needs to be understood alongside the condition of the ventilation system during testing.

Look for clear descriptions of fan operation, control settings, and the condition of air inlets and outlets. Distinguish between a fan being switched off and a ventilation opening being physically blocked: those are different test configurations. Temporary sealing that is absent from the delivered product can make a result unsuitable for the intended comparison.

The same scrutiny applies to the door. Confirm that the report describes the normal closed condition, including the relevant seals and closure hardware. Additional tape or temporary treatment should be identified and assessed against the supplied construction.

Interior fittings also deserve attention. Upholstery, acoustic lining, furniture, and floor finishes influence the sound field inside an enclosure. A furnished specimen and a substantially different production interior should not be treated as identical without supporting explanation.

The practical question is whether the tested condition represents an achievable operating condition for the product being purchased. If two reports use different conditions, record that difference before drawing a performance ranking.

Separate a laboratory report from a certification claim

ISO 23351-1 is a measurement standard. A statement that a product was tested using it does not automatically mean the product holds an independent certification covering ongoing production.

The supporting report should identify the testing organization, report number, issue date, specimen, method, and results. Check the cited edition of the standard and any stated deviations. If the reports reference different editions, establish whether the differences affect comparability.

Where laboratory accreditation is part of the procurement requirement, examine whether the relevant test method falls within the laboratory’s accredited scope. A laboratory’s general accreditation does not establish that every service it offers is covered.

Read the measurement uncertainty information where provided. A small numerical lead should not carry more weight than the evidence supports, especially when configurations differ. Avoid assigning a precise performance advantage from rounded brochure figures.

If a supplier presents a letter grade or performance class, identify the classification scheme and its boundaries. Keep the measured result visible alongside the label so that a convenient category does not conceal differences in the underlying evidence.

How to handle a product specification with an unexplained dB claim

The TB-ML 2400 Soundproof Meeting Booth, for example, lists external dimensions of W2400 × D2400 × H2300 mm and a sound insulation figure of 28–30 dB, with reference to an SGS or Institute of Acoustics, Chinese Academy of Sciences test report.

That specification provides a starting point for document review. The stated range should not be entered into an ISO 23351-1 comparison as D_S,A unless the supporting report identifies it as that quantity under the relevant method. The testing organization’s name alone does not explain the metric.

For this enclosure, useful checks include whether the report covers the quoted dimensions, laminated glazing, door assembly, and ventilation configuration. Its adjustable ventilation also makes the documented operating setting relevant. These checks connect the published specification to the evidence without assuming a particular acoustic outcome.

Turn comparable results into a purchasing decision

A stronger laboratory speech reduction result generally supports better containment of speech, but workplace privacy also depends on speaking level, listener distance, surrounding background noise, and installation conditions. A quiet room can make residual speech more noticeable than a busy open office.

ISO 23351-1 results also do not provide a complete assessment of noise entering the pod, reverberation during video calls, or ventilation noise at the user’s seat. Assess those requirements separately when they affect the intended use. Speech containment for routine calls and confidentiality for sensitive discussions deserve different acceptance criteria.

Use a short comparison record for each shortlisted model:

• Evidence: full report reference, laboratory, standard edition, and reported quantity.
• Configuration: model, dimensions, construction, fittings, and differences from the proposed supply.
• Conditions: door closure, ventilation state, control settings, and any temporary modifications.
• Result: speech level reduction, stated uncertainty, and any classification scheme used.
• Application: intended location, privacy requirement, and additional acoustic acceptance checks.

Carry the accepted configuration into the purchase specification. Identify the report and define how changes to doors, seals, glazing, or ventilation will be reviewed. After installation, inspect assembly quality and assess performance under agreed workplace conditions. This connects the laboratory evidence to the enclosure people will actually use.