What is ISO 23351

ISO 23351 is an international standard for measuring speech reduction in enclosed, furniture-like workspaces such as office booths. It evaluates acoustic performance under real-world conditions, accounting for factors like openings, ventilation, and installation environments, making it more relevant than traditional wall-based metrics for assessing speech privacy.

Why ISO 23351 Matters for Modern Acoustic Spaces

ISO 23351 was developed to address a gap in how acoustic performance is measured in modern work environments. Traditional metrics were designed for sealed walls and controlled laboratory conditions, which do not reflect how enclosed, furniture-like spaces actually function. Office booths and similar environments include ventilation, openings, and real-world installation variables that significantly influence how sound behaves.

This standard focuses specifically on measuring speech reduction in conditions that mirror everyday use. By doing so, it provides a more accurate understanding of how much conversation is reduced as it leaves a space, which is directly tied to speech privacy and overall usability. Rather than relying on idealized testing scenarios, ISO 23351 captures the combined impact of design, structure, and airflow on acoustic performance. This makes it a more practical benchmark for evaluating enclosed workspaces, helping set clearer expectations around how they perform in real environments. By aligning testing with actual use, it shifts the focus toward outcomes that matter, such as reduced distractions, improved focus, and greater confidence in conversational privacy.