STUDENTs

Pierre Teo

SEMESTER

HS24

Pierre Teo

Assignment 1

Space 1: Underpass from Bernerstrasse Nord to Bernerstrasse Süd 

The underpass is a long tunnel with 2 exits on both sides. As it is not enclosed, noise from the road enters through the openings. The floor is paved and the walls and ceiling are both concrete.

As an underpass, the space is purely meant for transit and dwelling is not its intended purpose. 

I found this site interesting as the noise from the road is filtered and muffled by the walls of the underpass. It was raining at the time of recording, which changed the pitch of road noise produced (higher pitch), as well as introduced periodic splashes of water dripping from the underpass roof-edge.

ambient sound of space

Recorder Location 1: at the end of the walkway

When I clapped, there was some fluttering echoes as well as a long reverb. This is probably due to the presence of parallel walls and the long space allowing for a long delay time and sound fall-off.

clapping from standing height (recorder was on the floor)

When I spoke, my voice felt boomy and grand. It felt like my words had a lot of weight. Speaking at increasing distances from the microphone, I tried to maintain a constant speaking volume, and thus could hear that my voice in the recordings got quieter.

speaking at increasing distances (un-normalised)

After normalising for volume, my voice felt like it got deeper and had more bass the further I walked. The direct sound from my mouth was also getting drowned out by the room acoustics.

speaking at increasing distances (normalised)

As I walked towards the center of the underpass, I noticed a new phenomena. As I spoke, there was a specific frequency which reverberated louder than the rest, seemingly coming from above.

Recorder Location 2: At the middle of the walkway

To capture this, I moved the microphone to the middle of the walkway, and spoke at standing height.

speaking at the middle of the walkway

Space 2: My Room

My room is essentially a perfect cuboid with textured plaster walls, linoleum floor, and a bare concrete ceiling. The room has a few clothes hung and objects strewn about, but is otherwise quite bare.

Of course, as a room, its primary function is for dwelling, and many times for an extended period. Between working and sleeping, the space should be calm and one which encourages quietness.

I found this space interesting as understanding what I like or dislike about its acoustic qualities could inform actions I could take to improve the space for myself.

I placed the recorder on my desk closest to the center of the room for all the recordings.

The gain on the microphone was at its maximum (10) for this recording as it was very quiet. The only noise I could hear was the occasional car which drove past.

ambient sound of space

My first clap was high pitched, and caused a clearly audible fluttering sound. For both claps, though much less pronounced as in the underpass, there was clear reverb, though it did not last long after the initial sound.

recording of clapping

When I spoke, my voice felt boxy and tight. There was a noticeable reverb, but because it didn’t last long, I felt like I could tell I was in a small room.

speaking at two distances (un-normalised)

Compared to when in the underpass, there was little difference between the original audio and the normalised audio. This is probably due to the small room not making the audio attenuation that significant.

speaking at two distances (normalised)

Assignment 2

Exploring the Emotional Impact of Everyday Sounds

Space 1: S5 Train from Zurich Hauptbahnhof to Altstetten station

RE (Switzerland) | ShowMeTheJourney

I’m seated on the lower deck of the cabin. The train is quiet with some chattering from the other passengers. There are no natural sounds in the space. Every few seconds, I hear and feel a rumble as the train goes over the break in the track, though at high speeds this quietens to the point its barely noticeable. As the train moves, there’s a low whirr of the engine which increases in pitch as the train accelerates. This constant noise is made up of 2 pitches which rise and fall in harmony. In front of me, a quiet high pitch hiss can be heard, possibly from the air ventilation system. 

When the train is in motion, over every other sound the voices of people talking are by far the most apparent. When the train stops, the pneumatic system of the door hisses as the doors open with a loud beep, catching one’s attention over anything else happening in the cabin.

While the rumbling of the train tracks present quite prominently when the train speed is low, it quickly recedes to the background when the train picks up speed. In contrast, the rising pitch of the train engine gains prominence as it seems louder the faster the train accelerates.

The space feels dead and there is little reverb when anyone speaks. Perhaps as a result, people speak with lowered volumes, leading to a calmer journey and experience. The conversations thus didn’t contribute to any stress or discomfort during the ride. In addition, the rhythmic low pitch rumble of the train track was somewhat meditative and pleasant, and the air ventilation system and engine whirring quickly disappears as background noise after getting used to it.

The entire environment thus felt calm and peaceful despite the various sounds occurring from various sources.

However, when the train stopped, the beeping and the pneumatic hiss of the train door disrupts the feeling of calm as they are disproportionately louder than the other sounds in the space. In addition, they are quite piercing noises, with the beeping playing repeatedly, and the hiss releasing suddenly.

Other than those noises which caused discomfort or drew my attention, any sudden loud noise would easily overwhelm the quiet environment, be it a phone call or an announcement through the intercom.

Space 2: At the ground floor patio of my student apartment

Im seated at a chair on the ground floor of my apartment. I’m surrounded by accommodation blocks on 3 sides, and a road on the last side about 30m away.

I hear foremost the cars on the highway not too far away. The tires rumbling across the tarmac is the loudest noise present. Ever so often a car drives past the nearest road and momentarily takes focus, though a truck on the highway is still louder, as the truck-body vibrates.

Behind the cars and human-made sounds, trees in the yard rustle as the wind blows. In occasional gusts, the trees rustle loudly, and some leaves drop to the ground, making sounds as they scatter across the gravel and concrete floor. Tiny birds (maybe insects?) make tiny chirping and rustling noises ever so often, though when the cars and leaves are loud, they’re unnoticeable.

Overall, the sounds here are quite comparable in volume, with no sound being clearly louder than others (like the door beeping in the train). At times, the rustling leaves are the loudest and most prevalent. The high pitch rustle also helps to make it seem louder. At other times, the trucks take precedence. Their large clunky frame knocks and vibrates as it passes, drawing attention to itself, even though I don’t hear or see the truck directly. When this happens, the other sounds fall into the background, like they’re taking turns to speak.

Definitely, the tiny birds and insects hidden in the area are the most overheard. They only come out when actively listening, and when the other noises momentarily wane.

Overall, this was another peaceful space, though for a different reason than in the first space. Here, every sound seems to be quite distant. The tall trees which rustled the loudest were about 100m away. The highway from where cars made the most noise were hidden behind 2 apartments blocks, meaning that the sound I did hear was muffled and less sharp (this was drastically different to when I did my first assignment directly under the highway). The gentle exchange of nature and human sounds were pleasant and comforting, and the occasional visits by the small animals was delightful.

There were times that the peace was disrupted, though. When cars would pass by the nearest road, the direct sounds coming from the tires were uncomfortable and unwelcome. When huge lorries would speed on the highway, sometimes even the apartment blocks wouldn’t be able to sufficiently dampen their sounds. For the whole period of listening, I didn’t hear anyone speak, so when right at the end someone walked along the closest street while speaking on the phone, I was suddenly thrown out of the serene space and couldn’t focus on anything but the conversation they were having. Funnily, it was the most disruptive sound there.

Assignment 3

I realised when drawing the linear line across the envelope that due to the erratic peaks, the line that I drew would not be accurate. To minimise error, I recorded 3 different claps and did my best estimation of the envelope gradient.

Task 1, Space 1: Underpass

Screenshot

RT60 = 2.04s

Task 1, Space 2: My Room

RT60 = 0.384s

Interestingly, when I clapped, I heard a longer reverb at a specific range of frequencies. In the Spectrograph view, I could see the longer trail of that range.

©

Architectural Acoustics

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