Browsing by Author "Gaspard, Adrian"

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    Sound Ecology and Acoustic Health, Part 1: Developing a basic Android Application
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-07) Gaspard, Adrian; Smith, Michael; Lepine, Nicholas
    Introduction to periodical article: A background level of urban noise is, unfortunately, one of those inconveniences that we must put up with to live in a community. You and your neighbour can sympathize with each other at a BBQ about being awakened by the dawn chorus of birds or early morning commuter traffic noise. You can band together to solve that problem with a joint big win on the local lottery and buy new houses elsewhere. Sometimes, the noise can be such an issue across a wide community that even federal politicians can be stirred from their comfortable seat to assist in the investigation as in the case of the Windsor Hum (2009 - 2014, zugislanddocumentary.com). However, as mentioned in our urban noise article Circuit Cellar issues, the BBQ conversation might go along these lines. You say “That noise at 2 a.m. every night last week, hasn’t it been driving you crazy?” and your neighbour responds “What noise?” After such a conversation, it is worthwhile getting your hearing tested. There are conditions affecting the ears, such as Tinnitus or “ringing in the ears”, which could be alleviated with professional help. However, with that issue ruled out, you now have a noise in your house that nobody else in your neighborhood seems to have. It’s time to become a noise detective. There are apps to record your prowess in “singing in the shower” and those, to a limited degree, would be useful in capturing the noise. If your neighbour agrees, check at their house or in their garden. Everybody’s hearing is different and there’s a possibility that the noise you are hearing is there and they are just not sensitive to it. Recording is good - it confirms that something physical is present in several locations. However we want a little more than that. We have been working with local Acoustics firms who have suggested that people should look out for “home resonances” as playing a role in noise nuisances you hear and your neighbour does not. We have all seen neighbourhood kids playing with resonances - tiny, gentle kicks of their legs at just the right time can cause a playground swing to reach great heights. In a similar way, parts of your house - wall, basement concrete pad, or heating duct - can be constructed in such a way that they sympathetically vibrate with, and amplify, some tiny, gentle, totally insignificant incoming vibration through the air or ground. To analyze the frequency response of your house including resonances we need a “recording app” with a number of custom DSP extensions for resonance identification. Rather than undergoing the hassle of trying to gain access to - and then modify - the source code of an existing app, we took a more pragmatic approach. If the local teenagers can build their own Android apps, surely we can too! To build our own recording app, we would customize from online Android tutorials (developer.android.com/training). Fig. 1A outlines our plan for our first Android activity built without any teenage assistance necessary. When this WAT_AN_APP is finished we will be able to record and playback an audio .3GPP file using a modified Android MediaRecorder app and be able to better show to others that the noise problem we hear physically exists. However we also want to be able to use our own DSP experience from work to add any special analysis feature. In future articles we will look at using a different Android activity approach that allows us to capture sound into an uncompressed data buffer. Fig. 1B demonstrates that goal of using some DSP “spectral” analysis to identify an unwelcome “spectral” presence, a ghost. We extend the app to do more sophisticated analysis that uses graphics to display the presence of home resonances that might be impacting the acoustic health of your home.
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    Sound Ecology and Acoustic Health, Part 2: An Android Application for Recording Noise Nuisances
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-08) Gaspard, Adrian; Smith, Michael
    Introduction to periodical: In our last month’s article, CC Issue 300, we light-heartily discussed a supposed back yard BBQ discussion between neighbours about urban noise nuisances. Unfortunately noise nuisances are real in some of our local Calgary Communities, and we are looking for some simple, inexpensive approaches to help people investigate and reduce the problem. We demonstrated the first steps of our solution - the development of an Android project with basic code to generate a main screen with a button that generated a welcome screen when pressed. We called this a WAT_AN_APP, meaning we were able to develop it Without Any Teenager Assistance being Necessary. In this article we want to extend our basic WAT_AN_APP project to recording and playing-back audio .3GPP files as shown in Fig. 1A. This will allow us to record any physical noises present that are less easily heard by others in your house or need more study as they are less noticeable during the day as they are hidden under traffic noise. In this article, we want to take a more adult approach – use a JEAC process that uses Just Enough Additional Code to make the new recording activity work.
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    Sound Ecology and Acoustic Health, Part 3: A Quantitative Ghost Hunting Application
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-09) Gaspard, Adrian; Smith, Michael
    Introduction to periodical: After CC Issues 300 and 301, we could boast to our local teenager that “WE” have developed an Android application. Last month, CC Issue # we added “just enough additional code” (JEAC) to record and play-back .3GPP files so we could show our neighbour at a back-yard BBQ that – “I am not imagining things -- look there are really local urban noise nuisances” (Fig. 1A). This time we are going quantitative with an audio record and analysis update of the WAT_AN_APP application for “Things that Go Boom at Night” – TGBN. This will either enable us to request lots of commiseration as the community noise are really bad or boast that we have more ghosts going “BOO(m)” at night than anybody else! QUICK RECAP: The idea is to leave the TGBN device running over a weekend. We are going to capture a 7 seconds sound recording if the community noise sound level gets above background level. When the sound stays high in intensity, a warning message (Android toast) will appear on our device’s screen. As a precaution, a scary “Boo” kind of sound will be outputted to intimidate any ghosts that MIGHT be present as we head off in the opposite direction.
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    Sound Ecology and Acoustic Health, Part 4: Time Domain Analysis
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-10) Gaspard, Adrian; Smith, Michael
    Introduction to periodical article: We have spent the last while working towards a mobile phone application to help identify a local noise nuisance problem. We joked with Mike’s neighbour’s kids that the record and play-back .3GPP file WAT_AN_APP application, Fig. 1A, was to impress them that “Without Any Teenage Assistance Necessary, we could write an Android APP” CC Issues ###. We then added just enough additional code (JEAC) to store an audio record for later analysis CC Issues ###. To continue the friendly tease in CC Issues ###, we pretended that the project code was actually designed to detect – “Things that Go BOOm at Night+ - how many “TGBN ghosts” there are in the neighbourhood (Fig. 1B). As they say “Be careful what you wish for!” Our neighbours got interested in the community noise issues we were really trying to measure. They had their teenagers explore the acoustic health of their home using our work-in-progress. Late yesterday, a knock on the door revealed our neighbours asking for help. Their eldest teenager had gone to the University of Pennsylvania. According to the Penn Arts and Sciences website sites.sas.upenn.edu/ghosts-healing, a group of scholars from literature, art history, nursing, archaeology, religious studies, science and medicine wants to take research on ghosts seriously. So our neighbour’s kid decided to volunteer with this group. This turned into a term project -- working on analysing room acoustics as a possible source of “that friendly spectral feeling”. Hence the frantic email message they wanted to pass on -- Term’s nearly over! Could you please get Mike to hurry up and fulfill his promise in that first CC article of providing enough information to do some “real” digital signal processing (DSP) analysis? While he was at it – could he get Adrien to add some graphics’ capability to display the frequency characteristics of the sounds in a room to make my term report more interesting! In Canada, it always good to keep on the right side of the neighbour’s kids as they are a good (inexpensive) labour source for shovelling snow off sidewalks. So we decide to write a RoomAcoustics Analysis Capability addition. Actually we wanted to be able to say that we had Penn-ed some code (sorry for the pun ( :-). ). First we will explain how to reliably excite a room resonance that can be captured by our existing TGBN detector code. We will graphically display the room audio signal to give us a first chance to compare resonance characteristics in different rooms. We found that looking for small differences in the captured signals displayed as a function of time meant working (slowly) with a lot of data. So we added a way to generate frequency information signal of captured signals using a discrete Fourier transform (DFT) algorithm code we grabbed from the web. Fig 2A shows the background noise recorded in our university lab. Having noticed a possible small 727 Hz ghost sleeping next to our desk, we tried to move around the room to better record its characteristic, Fig. 2B. The frequency characteristics of our two records look too similar for us to be sure that we have a non-snoring ghost close by. We decided to wake it up by outputting a three second Chirp, a sound burst from 50 to 1000 Hz. Fig. 2C show the frequency response of the Chirp signal, but there is not much there other than measuring the poor low frequency of our phone’s speaker. However, we accidently got close enough that we woke up the sleeping ghost which significantly changed the frequency response of the room, Fig 2D.
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    Sound Ecology and Acoustic Health, Part 5: Frequency Domain Analysis
    (Circuit Cellar, Kick Media Corporation, U. S. A., 2015-11) Gaspard, Adrian; Smith, Michael
    Introduction from periodical article:; Last month we explained how finishing our mobile phone application for identifying community noise nuisance problem had suddenly become a “must complete” project for one of Mike’s neighbour’s kids at University. The eldest teenager had volunteered with a group of scholars from literature, art history, nursing, archaeology, religious studies, science and medicine wants to take research on ghosts seriously -- sites.sas.upenn.edu/ghosts-healing. The project involved working on analysing room acoustics as a possible source of “that friendly spectral feeling”. Fig. 1 B Last month we started working on fulfilling the promise from our first CC article to “provide enough information to do some “real” digital signal processing (DSP) analysis” We talked about grabbing the audio information and preparing it for display. This month we will handle the last part of our neighbour’s frantic email “Get Adrien to add some graphics’ capability to display the frequency characteristics of the sounds in a room to make my term report more interesting! The things we Canadians will do to stay on the right side of the neighbour’s kids so they will shovel snow!