Author Archives: Kathryn Aplin

Reverberant Spaces: Shanahan Center, HMC, 2-23 3 pm



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Description of the Space: The Shanahan Center for teaching and learning is the newest building on Harvey Mudd College’s campus, as of 2014. “The Shan” opens onto a set of wide stone ledges, leading down like stairs to the open basement level of the building. Sunk almost into a pit, the courtyard is nearly an ampitheater, and one could imagine performances on the rough tile ground. The stone along the walls is cool, smooth, and gray, and broken only by the glass wall of a lobby on the northern face. Above, open space stretches past the three stories of the building, the floors arranged so one would look up with the square walls framing the sky. From the first floor up, the walls are made of beige, plasticy tiles and windows. The courtyard is approximately 20 x 40 feet wide at the lowest level, with each ledge – along side smaller stairs – dropping down in steps about 3 feet wide and 3 feet tall.

Recording Setup: The microphone was placed at the edge of the lowest stone ledge, less than 1 foot from the edge and facing into the courtyard. The balloon was held 2.5 feet away from the microphone to combat ambient noise from outdoor sounds.

Reverberation Time:

30 db Decay: 0.36 s

50 db Decay: 0.94 s

60 db Decay: 1.36 s

Decay to background level: 1.55 s

Acoustic Description: We see in the spectrogram above that the background noise of the space is only the 400 Hz and below range. The balloon pop is clearly seen as we have more intense presence of frequencies throughout the spectrum as it is popped. In the spectrogram, we see not just the decaying of the overall sound to the background noise, but can see that the higher frequencies fall out first, while middle frequencies (up to about 1000 Hz) remain for the longest. Overall, the reverb time of 1.36 s is fairly fast. The courtyard echoes sounds, though the echo is not contained in the recording, but the length of the pop is sustained only for the brief moment. The stone walls reflect the sound back, but the steps and floor are more porous, and absorb the sound.

The longer sustained middle frequencies seen in the spectrogram may almost be taken for a muddiness in sound; what sounds that do carry are carried indistinctly. The rest of the reverberation is a general woosh of air that might almost be confused with the wind knocking down a chair or table. Still, the reflection off of the walls is audible in the recording.

It is of note that this courtyard is referred to sometimes as the “Shakespeare Plaza,” as the hope is that it will be a live performance space. Given the echoing and muddiness, it may prove to be an unwise decision, but as the space is untested for such performances as of 3/6/14, only time will tell.

Soundscapes: HMC, Hoch Shanahan Dining Hall, 2-23 5 pm



Location: The Hoch Shanahan dining hall is located in the middle of Harvey Mudd College’s campus. Within, the hall is primarily serviced by a single, large, open room. Though as tall as two story buildings elsewhere on campus, the hall itself is only on the ground level; within the dining space, the ceiling is very tall. The north wall is entirely windows or glass doors, and the ceiling is broken by skylights. The food service area is separated from the seating by a wood paneled structure that supports drink machines. In both the dining space and the service space, the floor is tile. The chairs are plastic, and the tables only appear wooden on the surfaces. In the food service area, counters are chrome or otherwise metallic, with sneeze guards all around. At the time of recording, the dining hall was several minutes into Sunday dinner: not the most populous meal, but various bodies entered and exited the hall and various areas, sparsely filling seats and eating.

Recording Setup: The microphone was placed on a table in the center of the dining area, pointed away from the north windows and slightly up, almost aiming at the open space above the service area. The table it was on had no people sitting at it, but surrounding tables were occupied.

About the soundscape:

At the time of the recording, the Hoch is quiet compared to it’s usual buzz of human activity. Still, there was a general hum of people talking almost constantly present; this is a keynote of the space, and is so typical a sound that it is tuned out almost to background noise. Similarly, intermittent clattering can be heard. This comes from both silverware on plates in the dining area, and the shifting of serving platters in the back. These clinks and clacks are an archetype, since the space is foremost a dining hall which means food and the presence of these utensils to consume it. Various signals are present as well. About 5 seconds into the recording (0:05), a beep can be heard. This is an individual “tapping into” the dining hall, arriving for dinner. At 1:05, a chair scraping against the ground is heard, signaling the arrival of someone else to a table. The sounds coalesce into a clearly social space, but still one primarily for dining. It is arguable whether or not any soundmarks are present in the recording. One may argue that the distinct laughter heard at 0:14, sticking out from the background noise, is a sound of joy. It may be worth preserving, as it s a characteristic only achievable in a relaxed, open atmosphere. But it may also be just a signal of the individual’s amusement, conveyed and then dissipating into the background again.