Milena Jonas Bem – jonasm@rpi.edu
School of Architecture, Rensselaer Polytechnic Institute
Greene Bldg, 110 8th St
Troy, NY 12180
United States

Popular version of 2pAAa7 – Acoustic Design in Contemporary Museums: Balancing Architectural Aesthetics and Auditory Experience
Presented at the 188th ASA Meeting
Read the abstract at https://eppro01.ativ.me//web/index.php?page=Session&project=ASAICA25&id=3869561

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Museums are designed to dazzle the eyes but often fail the ears. Imagine standing in a stunning gallery with high ceilings and gleaming floors, only to struggle to hear the tour guide over the echoes. Later, you pause before a painting, hoping for quiet reflection, but you get distracted by nearby chatter. Our research shows how simple design choices, like swapping concrete floors for carpet or adding acoustic ceilings, can transform visitor experiences by improving the acoustic environment.

The Acoustic Challenge in Museums
Contemporary museums often embrace a “white box” aesthetic, where minimalist architecture puts art center stage. Usually, this approach relies on hard, highly reflective finishes like glass, concrete, and masonry, paired with high ceilings and open‐plan layouts. While visually striking, these designs rarely account for their acoustic side effects, creating echo chambers that distract from the art they’re meant to highlight.

Testing “What if?” in Real Galleries

Figure 1. Room-impulse-response measurement in progress: a dodecahedral loudspeaker (left) emits test signals while a microphone records the gallery’s acoustic “fingerprint.” Photo: Aleksandr Tsurupa

To solve this, we visited museum rooms, recording how sound traveled in each space, like capturing an “acoustic fingerprint”, which we name room impulse response. Using these recordings, we built virtual models to test how different materials (e.g., carpet vs. concrete) changed the sound in the space. We evaluated three levels of sound absorption (low, medium, and high) on the floor, ceiling, and walls. Then we evaluated how these choices affected key acoustics metrics, including how long sound lingers (reverberation time, or RT), how intelligible speech is (Speech Transmission Index, or STI), and how far away you can still understand a conversation clearly (distraction distance).

Key Findings

1. More Absorption Always Helps: Our first big finding is that adding more absorption always helps—no exceptions. Increasing from low→medium→high absorption consistently: cut reverberation in half or more, boosted speech clarity by 0.05–0.10 STI points, and made speech level drop faster with distance (good for privacy).

2. Placement Matters: where you put that absorption makes a practical difference:

• • Floors yield the single biggest improvement, swapping concrete for carpet cuts reverberation by 1.8 seconds. However, it does not always guarantee meeting ideal results; supplemental ceiling or wall treatments may still be needed to hit ideal RT, clarity, and privacy levels.
  • Ceilings delivered the largest jumps in STI and clarity, showing the greatest overall increase in distraction distance and better sound attenuation. So, going from a fully reflective ceiling to wood and then microperforated ceiling panels is compelling for intelligibility.
  • Walls emerged as the ultimate privacy tool. Only high-absorption plaster walls drove conversation levels at 4 m below 52 dB and created the steepest drop-off, perfect for whisper-quiet exhibits or multimedia spaces.

3. A Simple STI‐Prediction Shortcut: Measuring speech intelligibility typically requires specialized equipment and complex calculations. We distilled our data into a simple formula to predict STI using just a room’s volume and total absorption—no advanced math required (STI ranges from 0–1; closer to 1 = perfect intelligibility).

Figure 2. Predicted Speech Transmission Index (STI) across room volume and total absorption area. Warm colors indicate higher STI in smaller, highly absorptive spaces; cool colors indicate lower STI in large, reflective rooms. The overlaid equation estimates STI from volume, absorption, and reverberation time. Source: Authors

Hear the Difference: Auralizations from Williams College Museum
Below is one of the rooms that was used as a case study (Figure 3). Using auralizations (audio simulations that let you “hear” a space before it’s built), you can experience these changes yourself. Click each scenario below to hear the differences!

Figure 3. Museum gallery (photo) and its calibrated 3D model. The highlighted gallery “W1” served as a case study for virtually swapping floor, wall, and ceiling finishes to predict acoustic outcomes. Source: Authors

Note: Weighted absorption coefficient (αw): varies from 0 to 1, higher = more sound absorbed.

Ceiling:

• Scenario 7: smooth painted concrete (αw = 0.01)

• Scenario 8: Wood tongue-and-groove ceiling (αw = 0.14)

• Scenario 9: Perforated Acoustic Panels 20–25 mm thick with porous backing (αw = 0.81)

The takeaway?
Start with sound-absorbing floors to reduce echoes, add ceiling panels to sharpen speech, and use high-performance walls where privacy matters most. These steps do not require sacrificing aesthetics—materials like sleek microperforated wood or acoustic plaster blend seamlessly into designs. By considering acoustics early, designers can create museums that are as comfortable to hear as they are to see.