Audio

I am on vacation in Chile and exploring various techniques for recording sounds around me. I do some outdoor recordings but try to focus on indoor environments because of my ongoing AMBIENT project. In this blog post, I reflect on how challenging it has been. Annual projects The recordings are part of my annual sonic rhythm project, which is my third annual project. In 2022, I recorded one sound action per day. That was with a very simple setup: my mobile phone and a Røde VideoMic Me-C, a directional microphone that can be plugged into a mobile phone through a USB-C connection. The simple setup was probably the reason, I succeeded in carrying out that project. ...

Ambisonics is a full-sphere surround sound format that captures audio from all directions using spherical harmonics. To convert it to binaural audio for headphone listening, you need to apply Head-Related Transfer Functions (HRTFs), mathematical models that simulate how sound waves interact with the human head and ears. HRTFs create the spatial cues necessary to perceive 3D sound direction and distance over stereo headphones. My favourite go-to-tool for converting media files, FFmpeg, unfortunately lacks native binaural rendering. However, it offers channel manipulation filters like amerge, channelmap, and pan. These provide basic channel operations but won’t produce true binaural audio. Here are some tips for how to make it work. ...

People often refer to “sound and video” as a concept pair. That is confusing because, in my thinking, “sound” and “video” refer to very different things. In this post, I will explain the difference. Sound and Audio In a previous blog post, I have written about the difference between sound and audio. The short story is that “sound” refers to the physical phenomenon of vibrating molecules, such as sound waves moving through air. “Audio” describes technologies that can capture and reproduce such vibrations. So a sound recording is stored as an audio file. Audio technologies include microphones, recording devices (both analog and digital), and speakers that can produce sound. ...

What is the difference between sound and audio? I often hear people confuse the terms. Here are a couple of ways of thinking about the difference. A good summary can be found in this blog post: Sound is vibrations through materials Audio is the technology to hear sounds coming from natural or human-made sources Another good definition is that audio is electrical energy (active or potential) that represents sound. From this, a sound recording is stored as an audio file. It is important to note that we are not only talking about digital audio files. Audio can also be stored on an analog medium, such as an LP or cassette, from which it can be used to play back sound. ...

1 January this year, I set out to record one sound action per day. The idea was to test out the action–sound theory from my book Sound Actions. One thing is writing about action–sound couplings and mappings, another is to see how the theory works with real-world examples. As I commented on after one month, the project has been both challenging and inspiring. Below I write about some of my experiences but first, here is the complete list: ...

There is always a need to add fade-in and fade-out to audio tracks. Here is a way of doing it for a bunch of video files. It may come in handy with the audio normalization script I have shown previously. That script is based on continuously normalizing the audio, which may result in some noise in the beginning and end (because there is little/no sound in those parts, hence they are normalized more). ...

After exploring some visualizations of kayaking, I was eager to see how a similar approach could work for walking. On a trip to the Norwegian mountains, specifically at Haugastøl, situated halfway between Oslo and Bergen, I strapped a GoPro Hero Black 10 on my chest and walked up and down a nearby hill called Storevarden. The walk was approximately 25 minutes up and down, and a fast-forward version of the video can be seen here: ...

Last year, I wrote about video-based motion analysis of kayaking. Those videos were recorded with a GoPro Hero 8 and I tested some of the video visualization methods of the Musical Gestures Toolbox for Python. This summer I am testing out some 360 cameras for my upcoming AMBIENT project. I thought I should take one of these, a GoPro Max, out for some kayaking in the Oslo fjord. Here are some impressions of the trip (and recording). ...

Today, I recorded Sound Action 194 - Rolling Dice as part of my year-long sound action project. The idea has been to do as little processing as possible to the recordings. That is because I want to capture sounds and actions as naturally as possible. The recorded files will also serve as source material for both scientific and artistic explorations later. For that reason, I only trim the recordings non-destructively using FFmpeg. ...

Last week, Ulf Holbrook defended his dissertation at RITMO. I was in charge of streaming the disputation, and here are some reflections on the technical setup and streaming. Zoom Webinars vs YouTube Streaming I have previously written about running a hybrid disputation using a Zoom webinar. We have used variations of that setup also for other events. For example, last year, we ran RPPW as a hybrid conference. There are some benefits of using Zoom, particularly when having many presenters. Zoom rooms are the best for small groups where everyone should be able to participate. For larger groups, and particularly (semi-)public events, Zoom Webinars are the only viable solution. I had only experienced Zoom bombing once (when someone else organised a public event with more than 100 people present), which was an unpleasant experience. That is why we have run all our public events using Zoom Webinars, where we have more fine-grained control of who is allowed to talk and share their video and screen. ...