Do I Need Acoustic Panels or Sound Masking?

In contemporary office environments, acoustic performance is a critical factor in productivity, wellbeing, and speech privacy. Two commonly specified solutions—sound absorption and sound masking—address fundamentally different acoustic challenges.

• Sound absorption manages reverberation and speech clarity within a space.
• Sound masking regulates ambient sound levels to improve privacy and reduce distraction.

Understanding the distinction between these approaches is essential to selecting the appropriate intervention for a given workspace.
 

1. Reverberation Control Through Sound Absorption

1.1 The Role of Reverberation Time (RT)

Reverberation Time (RT) is measured in seconds and represents the time required for sound within an enclosed space to decay by 60 dB—equivalent to reducing the sound energy to one-millionth of its original level.

In modern office environments—often characterised by hard, reflective finishes such as glass, concrete, plasterboard, and acrylic screens—excessive RT is common.

1.2 The Impact of Excessive Reverberation

When RT is too long:

• Reflected sound persists unnecessarily.
• Speech sounds overlap, reducing intelligibility.
• Conversations become difficult to follow.
• Occupants raise their voices to compensate.
• Overall noise levels increase as a result.

This effect is particularly noticeable in:

• Meeting rooms, where clarity of speech is essential.
• Open-plan offices, where multiple conversations quickly elevate background noise.

In simple terms, when one word does not decay before the next is spoken, speech becomes blurred and harder to distinguish.

1.3 The Function of Sound Absorption

Sound-absorptive materials—such as acoustic wall panels, ceiling tiles, or suspended baffles—reduce the number of sound reflections within a space. By limiting reflected sound energy, these treatments:

• Shorten reverberation time.
• Improve speech intelligibility.
• Reduce the perceived loudness of the environment.
• Lower the likelihood of occupants raising their voices.

Acoustic products are laboratory-tested, enabling acousticians to model and predict their impact on RT with measurable accuracy.

1.4 Outcome

Achieving an appropriate reverberation time ensures:

• Clear verbal communication.
• Reduced vocal strain.
• Lower overall noise levels.
• Improved comfort in collaborative environments.

 

2. Managing Distraction and Privacy Through Sound Masking

2.1 The Challenge of Fluctuating Ambient Noise

Unlike reverberation issues, which stem from excessive reflections, sound masking addresses problems associated with low or inconsistent ambient sound levels.

In hybrid and open-plan workplaces, occupancy and activity levels vary significantly throughout the day. This leads to unpredictable acoustic conditions.

2.2 Where Low Ambient Noise Becomes Problematic

There are two primary scenarios:

Closed Offices

Where sound insulation between rooms is limited, conversations from adjacent spaces or corridors can become clearly audible—particularly during quieter periods. While improving physical sound insulation is one option, structural changes are not always feasible.

Open-Plan Workspaces

When building services noise (e.g., mechanical ventilation) is minimal, human-generated sounds—speech, typing, footsteps—become highly noticeable. The fluctuating nature of these sounds increases cognitive distraction and reduces speech privacy.

In these environments:

• Voices travel further than intended.
• Confidential discussions can be overheard.
• Concentration is easily disrupted by variable noise levels.

2.3 The Role of Sound Masking Systems

A sound masking system consists of a network of ceiling-mounted loudspeakers designed to emit a carefully engineered, broadband sound—often described as similar to gentle airflow. Unlike music or white noise, the signal is tuned specifically to:

• Raise the ambient sound floor in a controlled manner.
• Reduce the intelligibility of distant speech.
• Minimise perceptible fluctuations in background noise.

The system is calibrated according to:

• Room layout and ceiling height.
• Existing acoustic treatments.
• The functional use of each space.

2.4 Outcome

When correctly implemented, sound masking delivers:

• Increased speech privacy.
• Reduced distraction from conversations.
• Greater consistency in perceived noise levels.
• Improved comfort for focused work.