We’ve been piloting the use of Tegrity Classroom 2.0 for the past 9 months at Tulane Medical School. I composed a ~7 min “how to” video on how it can be used to record and play back of lectures for those interested. Be forewarned that the volume level of the audio increases substantially during the playback of the lecture. Be prepared to adjust the volume!
How To Develop a Video Podcast
April 1, 2008
I created a “How to” video on creating video podcasts for the April 2008 meeting of the Southern Group on Educational Affairs (SGEA). I thought I would make it available to anyone else who has an interest in the topic. The 22 min video describes how to create a video podcast on either PC or Mac platforms. It also contains a brief commentary on my negative outcome with the use of a course blog at the end (there was a general lack of student interest).
Using an Olympus WS-300M for Recording Lectures
January 1, 2007
I tested various modes of the Olympus Digital Voice Recorder (Model WS-300M; ~$80 from B&H online) and decided that the following settings gave the best sound when using a Noise-Canceling lapel microphone (Olympus Model ME52W; ~$20). This model of microphone hs a 1 m long cord that plugs directly into the top of the digital recorder & does not need another adapter.
HQ mode - which has a sample rate of 44 kHz. HQ mode is slightly better than Standard Mode (22 kHz), which has a little distortion to it. LP has significant distortion.
Mic Sensitivity – Dict(ation) instead of Conf(erence). This cuts out a lot of background noise and dampens the “high pitch” overtones that I did not like. I am not 100% sure, but there may be more variation in audio volume when using this mode. I tried moving the mic up from mid chest to about 6 in from my mouth (near the first major button below the collar button), and this improved the sound a bit.
File Sizes: The Olympus recorder saves files in the WMA (Windows Media Audio) format, which can be listened to using either the Windows Media or Quick Time players. A 53 min lecture recorded at a 44 kHz sampling rate (HQ mode) created a file size of 12.3 MB.
File Conversion: If you want to upload or play the file on iTunes (e.g. you wish to store the files on an iTunes University website), you will need to convert the file to either MP3 or AAC formats. I used a software program called “Switch” (Vers. 1.05, 2005 Copyright NCH Swift Sound; shareware) on a Macintosh workstation to convert files to MP3 (the conversion takes 4-5 mins per hour long lecture). When converting the files from WMA to mp3, I tried using a slower sampling rate to reduce the file size (the smaller the file, the faster it will download). Doing this sacrifices some degree of sound quality. The following sampling rates resulted in the following file sizes and “sound quality”
Original WMA (44 kHz) file: 12.3 MB (53 min lecture)
Converted to MP3 at 32kb/sec : 12.1 MB file (almost identical sound) Converted at 24 kb/sec : 9 MB MP3 file (slightly less sound quality)
Converted at 16 kb/sec: 6 MB MP3 file (clearly detectible distortion)
The amount of distortion you wish to tolerate is highly subjective.
