Improvised Throw-able Microphone

Inserting microphone into soft toy,
Photo by Tom Worthington, CC-BY 2022

In a large classroom it can be difficult to get a microphone to a participant. So there are throw-able microphones available. These consist of a wireless lapel microphone inside a soft foam ball.

These throwable microphones can cost hundreds of dollars. So I made my own throw-able from a $10 soft toy. The toy has a zip, so I inserted a wireless lapel microphone into the fiber fill of the toy. I removed the metal tag from the zip on the toy, and replaced that with string, to reduce the risk of injury.

The idea is you can throw the unit to someone, without damage to the microphone. Some will automatically mute the sound while being thrown. But the improvised unit worked fine. The only problem was some of the toy's stuffing clung to the microphone, when I removed it.

ps: The soft toy is a "Boba Plush", from Toymate. I later obtained a Sheep toy from Kmart. This has a pouch n the underside for electronic to make a bleating sound, which I replaced with a microphone.

Low Cost Home Office Webinar Setup

This is my home office setup for teaching online. I will be discussing this in my Keep Calm and Carry Online Webinar. Normally I talk sitting down, as it is then much easier to access the equipment, and I can't wander out of shot. I use a small wired headset for better sound ($50). I use a wired keyboard (second hand $5) and wired mouse (second hand $5) to operate the presentation. I have tried various wireless headsets, remote controllers and pointing devices, but find they get in the way, get lost and the batteries go flat at inconvenient times.

I use a low cost laptop ($500) plugged into a 24 inch monitor (second hand $100). Internet access is provided by a 4G wireless modem ($50 plus $15 a month for access), plugged into a router configured to limit bandwidth ($100).

Behind the monitor is a web-camera (under $100) with a clip on telephoto lens (under $20). The camera is on a telescopic tripod, so I can push it down out of sight behind the monitor, when not in use  (and so it can't see me). I appear in front of a folding green screen (second hand $10, plus $5 for green paint). There is a sound absorbing pin-board behind the monitor, which can also b used as a green screen ($30).

Under the desk is an Uninterruptible Power Supply (UPS) , in case mains power is lost (UPS $10 secondhand, new battery $50).

Beside the monitor is a ring light for better illumination ($10) and my smartphone ($500). I dial-in to the video conference to provide a more reliable audio channel, and as a backup in case the power, laptop or primary Internet connection fails. Also I can monitor how well the audio and video is received using the phone.

I have an ergonomic chair to provide comfort (free second hand). The blood-pressure monitor is just to remind me how stressful online learning can be. ;-)

For a more advanced setup, see Nicolo Malagutti's  "A bespoke audio-visual set-up" (2021).

Zoom Phone App Uses Less Data Than Desktop

Recently I had to join a Zoom conference from the roadside, for which I used the Android phone app. To my surprise this used less data than the desktop computer application. Without video it ran at about 30 kbps and with 80 kbps. The desktop application uses 50 to 150kbps. Also it takes some discipline to keep the data rate down on the desktop, by not making the window too big, whereas the phone doesn't have a window sizing feature so you can't get it wrong. Those on slow links, or limited data plans might consider using the mobile app. Of course there is an even smaller data option: use Zoom's dial-in option, but then you get no chat or video.

Ask Zoom for a Low Bandwidth Option

Back in March I suggested to Zoom, they add a low bandwidth option which the participant can switch on (request #3204325, priority "high", 26 March). The documentation says screen sharing with video thumbnail is possible at 50-150kbps, but I could not get that to work, even when I shaped my network connection to that speed. As well as allowing to user to activate this manually, I asked Zoom to adjust their system so it came on automatically, sooner. Since then I have experimented with how to reduce the bandwidth Zoom uses, so it works better on slow links, particularity wireless ones. But there are many people who still have difficulties. On 4 August, Zoom replied to say my suggestion had been added to their feature request list. But it took Zoom four months to reply, so they don't seem to be in a hurry to implement this. If you think it is a good idea, please tell Zoom.

Wireless Headset Helps with Video Conferences

Video conferencing
with a Jabra Talk 5 Earpiece
and ANU CECS Beanie

Since February I have been in many hours a day of video conferences. So I purchased a Jabra Talk 5 Bluetooth earpiece.

With a USB Wired Headset

Previously I used two sets of wired USB headsets (I won a set in in an e-teaching competition and the other were $5 at a charity shop). These have comfortable padded ear-cups, and a boom microphone positioned in front of the month. This provides excellent audio quality, and excludes external noise. However, after a day of hours of video conferences, my ears start to feel squashed. Also the cable tethers me to the desk and I look a bit silly in them.

Jabra Talk 5 Bluetooth earpiece

The Jabra is a lightweight alternative, with a loop to go over the ear, and a selection of in-ear rubber tips. The microphone is at the stubby end of the unit closest to the mouth. Pairing with my laptop was fiddly until I installed the Blueman application for Linux.

The earpiece is comfortable, the sound is okay, but not as high quality as the headphones. The wireless range is adequate for my apartment. Also handy is that I can wear the earpiece with the ANU CECS beanie I received this-morning. ;-)

There are wireless headsets available for about one third the cost of the Jabra, but they have a much shorter talk time, and would not get me through the day.

There are a few glitches: it is difficult to pair the Jabra with more than one device. When I pair it with my phone, I then have difficulty repairing with the laptop. Also it is difficult to mute the microphone and be assured this as been done. The Talk 5 is the bottom of the Jabra range and there are units with more features, but it is adequate for my purposes.

My First Video Workshop

Yesterday I ran a video workshop for the ANU TechLauncher computer project students. Last year these were run in a purpose built building of flat floor classrooms. But due to COVID-19 all workshops are now online. One of the privileges of being a lecturer at a leading university is that you get to decide for yourself how you teach, as well as what you teach. Many advanced video technologies were suggested, but I decided to just use a Zoom video-conference, as it has been mostly working over the last few weeks, and it mostly worked this time.

I had prepared for the workshop, with two computers, and two Internet connections in my home office. There were also two colleagues authorized as alternate hosts to take over if something went wrong. Everything was working fine, up until the time for the workshop, when the cabled network connection stopped working. So I had to use WiFi, and at that point my wireless modem's connection to the mobile network also slowed down. But it was still fast enough for audio, and screen sharing, which is all I needed, and the video was also okay.

One of the problems with a live online session is not knowing how well it is working. What I realize now I should have done (and tell others to do), is to log the second computer in as a participant, so I could see how it looked.

However, my colleagues told me it was working fine. Most of the time screen-sharing was used. This reduces the video of the presenter to a postage stamp size, just to reassure the viewer. One problem at my end was that I then could not see participants or the text chat window (relying on colleagues to point out text questions).

I used the option of recording the video to the cloud (actually on the university AARnet system). The video was recorded at 1920 × 1200 pixels WUXGA resolution. I downloaded the hour of video (554 Mbytes, or about 10 Mbytes a minute), and then uploaded it to the university's Echo 360 video system. The video was then converted to the more widely used 1080p (1920 × 1080 pixels HDTV format), which took several hours. Echo 360's own editing tools were then used to trim the video. The editing was quick, but it then took several more hours for the video to be re-rendered. The video I then linked from the university's Moodle Learning Management System, and it loaded very quickly.

It would give a better result if I could skip the conversion step to change from WUXGA to HDTV. As well as making for a clearing recording, that should speed up the process. Perhaps I can set my monitor to HDTV resolution.

Also I have been using an online tool to create video slideshows with synthetic voice. It might be interesting to mix some of that content into the live videos. The idea would be to take the live recording and insert the slideshows at points where students had difficulty with a concept.

A fun idea would be to turn the live audio into text using a speech-to-text system, then paste that text into the slideshow tools automatic content search,  and insert the resulting stock footage into the live video recording. This would emulate an approach I use when chairing a live, or online session. When the speaker has no slides, and the audience seems to be getting bored, I search the web for relevant content and put it up on the screen behind the speaker (usually without consulting them first). It would be possible to have a system which did this live during a video conference.

Better e-Learning Tools for Combating COVID-19 via Zoom

Just gave my first presentation via Zoom video conference this afternoon. This was on "Better e-Learning Tools for Combating COVID-19" to early career academics at the Australian National University (ANU). These webinars are being held every two weeks, to help deal with isolation.

Zoom worked much like the other video conference tools I have used to present. The audio worked well, as did the video, but screen sharing had some glitches (very much like other conference tools).

While Zoom offers to share a window on my screen, I could not get this to work with the Linux operating system and Firefox web browser. As soon as I started sharing a window, it went black on my screen and for everyone else. Sharing my whole screen worked, but then I could not see the chat window or video from other people. This was a little like presenting to a dark room full of people (which I have done in Indonesia, during a blackout). The window sharing may be better supported on other operating systems and browsers.

Free open source alternatives to Zoom for Videoconferences

I spent much of the week in Zoom based video conferences, only one of which did not work. This is remarkable, given how heavily Zoom is being used due to the COVID-19 Coronavirus. In contrast, I had considerable difficulty with Blackboard Collaborate. Collaborate seems to be less able to cope with my 1 mbps broadband connection than when I used it at 28.8 kbps dial-up speed in 2011. 

There are also some open source video conference products. Hamza Mu has detailed 15 of them in "Top 15 Open source Video conference and Team Communication Solutions for Windows, Linux, Mac OSX and Phones (Medevel.com, 30 Mar 2019). The only one of these open source products I have used is BigBlueButton, which is commonly teamed with the Moodle learning management system. However, Apache OpenMeetings looks interesting.

However, these video conference tools have not changed much, from the user's point of video, for decades. The quality of the video has improved, but that is about all, and that is about the least important aspect of a video conference. These events should really be called audio conferences with a shared screen and optional video.

Tuning Zoom Videoconferencing

Today was my third video conference for the week, Reading the Corona: extraordinary responses during an extraordinary time, hosted by the ANU Indonesia Project. Chatib Basri and Rizki Siregar discussed policy options for dealing with the the COVID-19 Coronavirus in Indonesia.
With 300 participant, this Zoom video conference had many more than those yesterday, but worked much better. This is a good way to keep in touch, but I am worried about the amount of bandwidth which might be used. So I tried shaping (limiting) my network connection.

Shape Your Video Conference

I am using 4g wireless broadband, with two out of five bars of signal strength, running at 2.63 Mbps download, 1.54 Mbps upload and a ping speed of 34 ms from Canberra to Sydney (at other times it has been 9.1 Mbps download, 12.8 Mbps upload and pink speed of 29 ms). That is modest by current standards, but adequate for attending, and presenting at a Zoom video conference.

I stared shaping with 150 kbps, which is Zoom's recommended minimum, for screen sharing plus a thumbnail video. But Zoom reported an unstable link and it was unusable. Increasing to 512 kbps worked well. The video was then at 256 x 144 pixels and 5 frames per second (sometimes 320 x 180 at 12 frames per second). Shared screens were very clear at 1440 pixels wide, with a small, but clear, video window next to them.

Yesterday I was using video conferencing via the Australian National University's very high speed network. I discovered I could reduce the data requirements for Zoom by keeping the video window small. Today I am using a much slower cellular modem wireless connection. But with the bandwidth shaped, and resulting lower resolution video, the experience is much better than on the higher bandwidth connection.

I used the Linux tool Wondershaper to slow down my network connection, but there are similar tools for other operating systems (and using routers). Wondershaper is not ideal, as it slows down everything, not just Zoom (other tools can select just one application to shape). Of course it would be better to tell Zoom to use less bandwidth, but I have not been able to find a way to do that.

Flip your Video Event

Keep in mind that glitches happen with video conferences. Yesterday I had four scheduled Zoom meetings. The first two worked flawlessly. The third had some glitches, and the last did not work at all.

I suggest 'flipping' the format for online events. That is, provide the presentation slides and, if possible, a short recorded video by each speaker beforehand. That way, if there are intermittent problems, the presenters can skip the full presentation and go straight to questions. Also I suggest reducing the length of events, and break them up into segments of no more than ten minutes. For example, instead of an hour long seminar, make it 15 minutes, including 5 minutes for questions.

Organizers need to be ready to switch off the video, leaving just slides and audio, if there are bandwidth problems. Also the organizers should have copies of slides and be ready to manually change them, if the presenter has difficulty doing that at their location. They should be ready to just talk, with no slides, as I have told ANU TechLauncher students. 

Use Video Conferences to Keep in Touch But Conserve Bandwidth

Greetings from the Australian National University (ANU) in Canberra, where I just took part in the inaugural Virtual Morning Tea (VMT), for early career academics. These will be held weekly by the  ANU Network for Early Career Academics (NECTAR). There will also be more formal regular online seminars, but the VMT is an informal drop-in sessions to avoid social isolation. While this is a good use of technology, it is also a good idea to conserve the use of the public data networks, as there is likely to be high use of the coming months. So here are some tips. The video conferencing product being used was Zoom, but other products are likely to behave similarly.

It is possible to reduce data use, simply by using a small video window. With video full screen, I have found that Zoom uses about 1,000 kbps. If I reduced the size of the video window to around 512 by 240 pixels, the data reduced to 300 kbps. Minimizing the video to a "thumbnail" (200 by 112 pixels) reduced data to 220 kbps. Hiding the video reduced data to 120 kbps. This is consistent with Zoom's documentation: 1.2 Mbps for HD video, screen sharing with  video thumbnail at 50-150kbps, and screen sharing only with no video thumbnail 50-75kbps.

During a formal presentation, video is really only needed at the start to introduction the speaker, and at the end during questions, if at all. In between there are usually slides to look at, so the video can be minimized, or hidden. I suggest participant adopt that way of viewing, and if possible, event organizers set this up as the default.

There are other ways you can improve video meetings, especially with careful preparation. The aim is to have the live video meeting as just one element, ideally a non-essential one. Much can be done with text based communications, which are less demanding of networks, to keep people in touch.

Zoom, and other video products, adjust to the bandwidth available, but then tries to use all that bandwidth. This makes them poor online citizens, like someone who fills their trolley with toilet paper, if you let them.

As there is likely to be a high demand for Internet access over the next few months, I suggest that providers of video conference products set defaults to use less bandwidth. At the very least they could be set so only a small video window appears by default. Also they could provide a low speed option which uses no more than 256 kbps, and this could be made the default setting. As an example, Zoom has a maximum bandwidth setting, but this is disabled by default. This should be enabled and set to no more than 256 kbps.