Author Archives: bobbiec@andrew.cmu.edu

Dreams

The signal I convolved was a recording of Shia LeBeouf saying “Don’t let your dreams be dreams.”

The four signals I used for convolution were:
1. IR of metal structure outside Carnegie Museum of Art
2. IR of Cathedral of Learning Stairwell G, 4th floor
3. Recording of person falling down steps (www.freesound.org/people/cinevid/sounds/144160/)
4. Recording of single note from a synthesizer (www.freesound.org/people/modularsa…s/sounds/285519/)

The reverb from recording (1) had a lot of destructive interference which quickly killed the sound, especially compared to that of recording (2), which echoed back from 12 floors.

Recordings (3) and (4) were interesting to me because the outputs sounded pretty similar at first despite the differences in convolution signals. But closer listening showed the different frequency content in the output.

https://soundcloud.com/bobbie-chen/dreams

Time Delay based on Fundamental Frequency

For this assignment, I created a system which took the fundamental frequency of the audio signal and (after scaling it) used it to set a time delay. This same time delay is also used to control how often the fundamental frequency is sampled to set the next time delay.

The result is a new signal which stutters, especially around areas with large variation in fundamental frequency. The stuttering effect is compounded in this particular recording (Sidney Bechet’s “Si Tu Vois Ma Mère”, from Midnight in Paris) because of call and response, especially around 1:38 of the SoundCloud link.

https://soundcloud.com/bobbie-chen/bechet-stutter-1

The beginning to 3:13 is the original recording in the left channel and the output of the system in the right channel; 3:14 to the end is the output only. I tried to include the original recording as reference, but SoundCloud removed it for copyright reasons. Here is a YouTube link.

The Max patch is below.

———-begin_max5_patcher———-
1043.3ocyX1rjahCDG+rSU4cfhia43BDe3gbJU1yop8xdZcpojAYak.RrRhI
1I0NOK66x9hs5CvF7fYvPLwGLX2Rz7u+oVsj7Od6alYultGwssdu0eYMa1Oj
VlosorLqxvL6L393THW2QaB5az0ewddYaBzdg1dFlfyJxrBbbbN1JoPZNEIz
OJnlUZg3ElwIZGI8967WdzE4PQ7NLY6iLTrvHU+HuENysBhBT2dHRcE.V3X8
4pGhKNjhzd6neLuQwgbjwI1Xhvdt4l0m0c5ed6aT2k2lOdb.2qwA3mAMB6CM
BWpoQ38HM9MK2EAWEGbaiC98gCdZB3ELLNrIkBuMIDHAiplcX8AXr.+Dxxc7
.wqKfDD9fgD5DCWf6vHxZHY6n.RQ1ZDq8X08j7YPIgPrGQD3ZilbthYHfdjY
DZxIBbFFGTSOFKKxPbNbK5kYGNiNWv6gNQfmFA9QQiBA2jRCfwG6cWfLPOt6
6nmG.hVDLzBj24yB7dk5i532aY3u5YAWJUHESPOO5UKAcNQ.DAzICt54CdCb
0RNdKAldKYwluiXzmek7klvvqMXDzipBfHeMS7GyRlyq8kaETDvb4a+5nRa0
K5b2kfxRkAZbD3NpLjaCDvjm6Xe1WAHB6AHJ2+vxAlcHkaLkPzdc3v.88DX7
0Uavok3syYC.yBDkqQ5GTcs03cvQRdJ7PJl+pYwwo37cH71cZ0EoRCaMLCZa
6P8HLcMmax0rPPzHJA112TeRvx84RIP1A6StNAJfk3ohOlX83wPq2hrsM3T4
hgYF476ue0p+jiX7Uq9Hc8ZLZ0pOUvwwmtgIEXg0+8uV+Ajg4u6S3DhhgVXh
wxhr7iaZtx8eESLrCVjfoJK06AGkhzAhQfZb4ViVp9jRo40G8zAEkHPDwibA
TfpB4Fwlb3AKGd36vaJGaNyuxTGZxo8gKiP6lMugllR+11T5ZXp.kkSK0Xyd
QY3sXRid3BbN+UwSKXBbF5XX1r4+t.lhEG5PLZahBBVU7Wu7h+EDhbDcqXWM
dZKvwek+hfikAIWhLZzESYrFCNM6iJb3BFR1yNAiQOY7KD5pors977bDJ4B5
qT8snvicpr7Q4WqZnx5ohKFGq2dz4+YM542pFNqjCmVvhqxbJKITS81IRtHi
7S5pp7X8NsCmjfHMpklf4pMlpCZmKWCr+xpW5R8GfL0BKrWBa4zKrk8RXfIW
XpCf1Cg4O8DCzKgIWVvxcZElWeD14b8tYnDL8BCzKgM8SJAA8Zjb5Ki4E16T
roM2O79bfzuIHZWVg2q4W92m7BD7KQWN2g5ZYe2F1vmMVtaQXd9SxCJU5Yih
jmD8KTl52Kma9MlX9swy1LzS3pGIzXBxjGfTH2BaAybFr8gkGuTe3Dl77V5S
9Hsn0f7x+CDsCtXB
———–end_max5_patcher———–
view raw gistfile1.txt hosted with ❤ by GitHub

Sitting Stretched

For this assignment, I took the eponymous line of Lucier’s “I am sitting in a room” and repeatedly processed it using a few of Audacity’s built-in features.

Originally, I had intended to simply change the tempo of the recording and add echo with each iteration, but I found that doing so led to an extremely uncomfortable beating effect as the sampling rate became perceptible. I switched to using Paulstretch, which allows for extremely long stretching without losing (subjective) quality. I also added a low-pass filter at 5000 Hz to prevent the high frequencies in the “s” sound from dominating the recording.

On each iteration, using Audacity:
Paulstretch – Stretch Factor 1.15, Time Resolution 2s
Echo – Delay Time 0.35s, Delay Factor 0.15
Low-pass filter – Cutoff Frequency 5000 Hz,  Rolloff per octave 6 dB

The end result after twenty iterations (all included in the link) is a soundscape which is completely unrecognizable from the simple original message.