Space_01 Atelier Space HIL G75

1. Acoustic Profiles

The analysed space is an atelier studio measuring approximately 8 × 16 m with a ceiling height of about 4 m, accommodating around 30 architecture students. The room supports multiple modes of occupation, including individual-focused work, small group discussions, and collaborative model making, producing a dynamic acoustic environment with fluctuating sound sources.

The studio is a fully enclosed space characterized by predominantly hard and reflective surfaces. The floor is finished in polished terrazzo, which has a high sound reflection coefficient and contributes minimally to sound absorption. Two sides of the room are composed of glass partitions, while another side includes metal panel partitions, both of which are acoustically reflective materials that tend to promote specular reflections rather than absorption.
Below is an audio of when the space is used and how it sounds:

Despite the large volume of the room, the perceived reverberation time (2 sec) appears relatively short. Speech does not propagate strongly across the space, and the overall sound field feels acoustically contained or “boxy.” No sound is amplified by the reflections, and the noise feels boxy. I guess that the ceiling lined with perforated metal units is what helps absorb most of the reflections.

2. Characterization of Room Acoustic Treatment

The main acoustic absorption in the space seems to come from the perforated metal ceiling, which is spread across the whole room. It probably has some kind of backing material, so it absorbs sound well, especially in mid and high frequencies, which is why clapping sounds die out almost immediately. Low-frequency absorption is likely not very strong.

There are also blinds on the glass sides, which may add some extra absorption when they are in use. Other elements, like people and furniture, contribute slightly but are not major absorbers.

The room has a lot of parallel surfaces like the floor, ceiling, and glass walls, so reflections still happen, especially sideways. The rubber terrazzo floor and glass are very reflective, so they bounce sound quite strongly.

Furniture like tables, chairs, and plywood partitions (tagboards) help in slightly breaking and scattering sound, but they don’t create strong diffusion.

The absorbers are mostly only on the ceiling, so the absorption is not fully balanced across all surfaces. This reduces overall reverberation, but also makes the space feel a bit “boxy”.

Visually, even though the room feels like it should have a lot of reverberation, it doesn’t; the ceiling is well integrated into the design and doesn’t look like a separate acoustic element. It feels like part of the overall architectural system.

3. Empirical & Numerical Estimation of Room Acoustic Properties

The claps, as you can hear, diminish very quickly, and feel like the room is very closed off. To measure the reverb time, we can measure the slope and calculate it from the logarithmic graph.

From the above reading, we get to see that it drops from -20 dB at 9.50s to -50 dB at 9.81s. This means that the reverberation time(time taken for 60 dB drop) is going to be twice (2x) of this 30 dB drop, i.e., RT60 => 0.31s x 2 = 0.62 seconds.

Space_02 Bridge Between Two HIL Blocks

1. Acoustic Profiles

This space is a bridge that connects two separate blocks of the HIL building. This is often used in transit, meaning no sounds from paused sources. It being a semi-open space allows a lot of background sound from the surroundings to be heard.

The floor is concrete blocks, and the ceiling is clad with a metal GI sheet. Both these reflective materials help produce a reverb. There is a slight flutter that occurs when clapping. The reverberation sounds clinky, sort of like a metallic ring to it. At a certain distance from the opposite door, I was able to hear an echo and flutter as well.

Final Assignment

Optimizing HIL D24.1 to a Gaming Arcade

The room’s existing condition presents parallel hard surfaces on all six faces, which creates conditions for flutter echo and elevated reverberation across the mid and high frequency range. This makes it unsuitable in its untreated state for a noise-intensive use such as an arcade.

Parameter	Value
Volume	629 cu.m
Geometry	cuboidal
Dominant Surfaces	Hard plaster walls + concrete ceiling

The room is proposed as a gaming arcade divided into two acoustic zones separated by a heavy drapery curtain partition. The curtain acts as a bilateral absorber — reducing sound transmission between zones while absorbing mid-frequency energy from both sides.

• Speech intelligibility between players is important
• Significant ambient machine noise demands controlled reverberation to avoid noise buildup
• A4 would be excessively dry for an entertainment environment.

Frequency(Hz)	Max Target
125	1.00s
250	0.75s
500	0.68
1000	0.68
2000	0.5
4000	0.6

Material Selection — Absorption Coefficients
Material selection was guided by the three absorption coefficient tables sourced from Commercial Acoustics® (Austin Peek, Nov 2025). The strategy assigns different materials to each surface to achieve frequency-selective absorption matching the A3 target curve.

Carpet absorbs primarily at 2–4 kHz without disturbing the low-frequency allowance. Gypsum plasterboard provides passive low-frequency absorption; drapery partition provides strong mid-frequency control.

Iteration 01:

Problem Identified: 500 Hz is over-reverberant while 1 kHz is already over-absorbed. The frequency curve is imbalanced — a broadband ceiling material would worsen the 1 kHz deficit. A selective, frequency-targeted ceiling intervention is required.

Iteration 02

Based on the Iteration 1 analysis, two targeted modifications were introduced: discrete ceiling wooden deck panels and additional side wall treatments.

Modification	Reason
Adding tongue & groove wooden deck in the ceiling	Addresses 500 Hz without further reducing 1 kHz. Smaller coverage area = selective, not broadband, treatment.
Angled gaming cabinet arrangement	Wood surfaces scatter reflections upward toward the absorptive ceiling rather than laterally between walls.

Clean linear decay with no flutter echo spikes or late-energy anomalies. The red envelope confirms a well-diffused decay field.

Final visualization of the room with the materials and atmosphere