Podcasting for E-Learning: Editing and Producing Podcasts

So far in this series of posts about Podcasting for E-Learning from the E-Learning Curve Blog, I've covered a lot of material, including:

• A Brief History of Audio in Education
• The Four 'P's' of narration
• Introduction to Audio Production
• Digital Audio Basics

Now, it's time to look in some depth at editing and producing podcast content.

As I discussed last time, non-linear editing applications are media editing tools which can randomly access the source material - and that’s it. You don’t have to edit audio in a beginning-middle-end sequence. You can also drop in new files, split audio, modify the volume (or amplitude), “top and tail” the recording, and add effects, before generating a rendered file which contains all of the modifications you made to your audio.

Non-linear editing enables the editor to access any frame in an audio clip. It can be viewed as the audio equivalent of word processing, which is why the process is often called desktop editing. Typically, audio is either recorded directly to a PC hard drive, or is imported from another source, in the same way as that text is either authored within the a word processor application, or a file is imported from another location.

In non-linear editing, the original source files are not lost or modified during editing. This means that you can easily make changes and cuts, experiment with the audio, and undo previous decisions secure in the knowledge that you are not interfering with the original - or master - files. Loss of quality is also avoided as you don't have to repeatedly re-encode the audio when different effects are applied.

While there are many excellent commercial, free-to-use, and open source audio editing applications applications available, the editor I will talk about during this series is called Audacity.

Audacity is an open source, easy-to-use multi-track audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems. You can use Audacity to:

• Record live audio.
• Convert tapes and records into digital recordings or CDs.
• Edit Ogg Vorbis, MP3, WAV or AIFF sound files.
• Cut, copy, splice or mix sounds together.
• Change the speed or pitch of a recording.

So, let's download and install Audacity.

You Try:

1. Navigate to the Audacity download page and select the download for your operating system.
   
   
   
2. Click on the appropriate link. This will take you to the SourceForge download page - don't "save link as.." or "save target as..".
3. The SourceForge download should start automatically. If it does not, click the links in the black panel marked "direct link" or "mirror". Only these links and the automatic download are authorized versions of Audacity. Disable any automatic download managers if the download is incorrect.

I also recommend that you download these optional files:

• LADSPA plugins 0.4.15 installer (.exe file, 1.5 MB) – nearly 100 audio digital effects plug-ins
• LAME MP3 encoder - Allows Audacity to export MP3 files

System Requirements: Windows-based Systems

The values in the "Recommended RAM/processor speed" column below are for tasks like recording for an hour, or editing three 20 minute tracks simultaneously. The values in the "Minimum RAM/processor speed" column will be fine for smaller/shorter tasks, especially if unused programs are closed.

Windows version	Recommended RAM/processor speed	Minimum RAM/processor speed
Windows 98, ME	128 MB / 500 MHz	64 MB / 300 MHz
Windows 2000, XP	512 MB/1 GHz	128 MB/300 MHz
Windows Vista Home Basic	2 GB / 1 GHz	512 MB / 1 GHz
Windows Vista Home Premium/Business/Ultimate	4 GB / 2 GHz	1 GB / 1 GHz

Audacity works best on computers meeting more than the minimum requirements in the table above. Where Audacity is to be used for lengthy multi-track projects, Audacity's developers recommend using Windows 2000, XP or Vista running on machines of substantially higher specification than the minimum specs outlined above.

Apple Macintosh

Installation instructions (MacOS 9 and OS X):

1. Inside your Applications folder, create a folder called "Audacity"
2. Double-click the downloaded .dmg to mount it
3. Option-drag the whole of the .dmg contents (not the .dmg itself) into the "Audacity" folder you created
4. Double-click Audacity.app inside the Applications folder to launch it

Mac OS X version	Audacity Version	Recommended RAM/processor speed
Mac OS X 10.1	Audacity 1.2	64 MB / 300 MHz
Mac OS 9.0	Audacity 1.0	64 MB / 300 MHz

Linux/Unix

Audacity's developers recommend using the latest version of Linux/Unix from your distribution that is compatible with your hardware specifications. Audacity will run best with at least 64 MB RAM and a 300 MHz processor.

Installation packages for Audacity on GNU/Linux and other Unix-like systems are often provided by individual distributions:

• Alt Linux
• Debian
• Fedora Core
• Fedora Project
• Mandriva i586
• OpenSUSE
• Red Hat
• SuSE and packman (suse)
• Ubuntu: packages.ubuntu and rpm.seek

This list is not comprehensive. If you don't see an up-to-date package for your distribution, search your distribution's web site for the latest information. Alternatively, you can compile Audacity from source code.

More…

New E-Learning Curve’s Other Podcast new episode release:

Transatlantic: The Flying Boats of Foynes. The Complete Podcast Documentary.

It's the 70th anniversary of the first scheduled trans-Atlantic air passenger service, which opened in July 1939. Told against a backdrop of the momentous events of World War II, this podcast documentary tells the story of the town of Foynes on the River Shannon in Ireland, which served as the western European base for the majestic flying boats of Pan Am, Imperial Airways and other airlines in the Golden Age of Aviation.

From their proving flights in the late 1930's through World War II and into the post-war period, Chief of Launch Operations at Foynes recalls his time working for Imperial Airways, and the effect of this glamorous mode of travel on a small Irish port. Even today, airplanes like the Catalina, the Short Empire class, and the majestic Boeing B-314 Clippers speak of a time now long gone.

Click on the link to celebrate the memory of the age, and the life and times of those who lived it.

Click here to listen to the podcast (MP3, 28MB).

Click here to listen to the podcast on iTunes.

Click here to view the transcript of this podcast (PDF, 585K).

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Podcasting for E-Learning: Benefits of Digital Audio

The first principle of digital audio is:

Digital audio is the study of discrete values.

This characteristic is very important: it allows us to manage audio information very efficiently. Using digital techniques, the capability to process information is greatly enhanced.

In a previous post, I discussed a little about the basics of digital audio. Today, I want to talk about how digital audio technology benefits podcasters. What are its advantages over an analog system of recording?

Here are a few specifics:

1. Less noise than an analog recording system.
   In an analog recording system, magnetic particles are oriented by the tape head in a manner that is analogous with the audio signal that is driving the tape head. The tape itself has billions of little magnets on it, and it is physically impossible to orient every single one correctly. These remaining magnetic particles are randomly oriented, which shows up on playback as what is called tape hiss. With a high enough sample rate and resolution, digital audio produces recordings that have significantly less noise than analog.
   
   The noise in an analog recording system is usually expressed as a "signal to noise ratio". The signal to noise ratio tells you how much more signal there is on the tape recorder outputs compared to the noise in a audio signal. For example, a digital audio system using a resolution of 16 bits will often yield a signal to noise ratio of more than -90dB (in EMG’s in-house studio the noise threshold is, for example) for decibel, a unit of measurement in the audio world. -90dB means that the noise floor is 90dB below the signal level.
   
   It would take a very high-end and expensive analog recording system to produce even a signal to noise ratio of -60db. This difference of 30dB is dramatic: the noise floor in the analog recording system will be 1000 times louder than the noise floor in a digital system. The reason for this is quite simple: a digital recording system records only the binary numbers, not analog signals which accumulate noise from the imperfect recording process. Since a digital system only records numbers (zeroes and ones, or bits, to be specific), as long as the bits can be recorded and read by the digital tape or digital disk system, then the only thing that matters is the theoretical 6dB per bit of dynamic range that is determined by the resolution of the digital recording system.
   
2. Ability to make copies without signal loss.
   Another advantage of digital audio over analog is the ability to make as many copies of the original as you want without degrading the signal quality. Every time you duplicate an analog recording, you lose audio quality and add even more noise. Remember that digital audio is just a group of digital samples, made up of zeros and ones that represent the audio.
   
   These numbers can be "copied" to another device or medium in a way that ensures that the result is the same as the original. This means that the copy is a "clone" of the original and sounds the same. This is true for the first copy or the seventy-first. Each time you copy an analog recording, you introduce between 3 and 6dB of noise, which further reduces the signal to noise ratio. Clearly, for pristine back-up want to use multiple copies of material during production, digital has the advantage.
   
3. Better audio quality for a lower cost.
   Digital audio used to be much more expensive than analog. This was because the early digital tape recorders used expensive and precise reel-to-reel mechanisms and early digital technology which was inherently more expensive. As recently as five years ago, the cheapest digital multi-track on the market was over $10,000 - analog reel-to-reel machines could be had for a fraction of that price. Now, digital technology has advanced to the point that this is no longer true.
   
   This is much in part to the advancements made in digital technology due to computers as well as cost reduction of other technologies important to digital recording like video cassette mechanisms and hard disk drives. Since digital audio technology uses similar components as the computer and multimedia industries, digital audio devices can take advantage of the lower cost of components due to their high manufacturing volumes. The result? Today's digital audio multi-tracks not only out-perform analog machines, costs less to manufacture, and is quite easily integrated into a multimedia production environment.

More...

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New E-Learning Curve’s Other Podcast episode release:

Part 7 of Transatlantic: The Flying Boats of Foynes

In Part 7: End of an Era

The War in Europe ended on May 25th, 1945. As normal life re-established itself, times also began to change for Foynes. Larger and more powerful airplanes had been built and operated successfully. A new land-based airport was established at the far side of the river. It was called Shannon International.

In this final episode of Transatlantic: The Flying Boats of Foynes, Chief Operator of Launch Operations Frank Buckley describes the end of the flying boat service in Foynes, Ireland, and the emergence of Shannon airport as the new home for transatlantic aircraft in the Post-War years.

Click here to listen to the podcast (MP3, 8.5MB).

Click here to view the transcript of this podcast (PDF, 24K).

Even though this is an e-learning blog, the observant among you will notice that the podcast isn’t about e-learning. That’s OK – the point of e-learning is to provide training professionals with a means of creating and distributing content that enables people to acquire information, knowledge, skills, and expertise on a diverse range of subjects: as e-learning practitioners, it’s our job to facilitate this process.

Podcasting for E-Learning: Critically Analyzing Podcasts

My previous blog posts on podcasting have focused the human side of podcasting: narration, story-telling, communicating with your audience. I've looked at what you say, and how you say it, dipping liberally into the eighty or so years of accumulated skills and knowledge from radio broadcasting to reinforce my arguments - after all, content is king, and radio is still the place where people talk.

Now, it's time to spend a little time understanding the technical aspects of podcasting. Don't worry if you've never so much as looked at a sound file before. Recording and producing your own content is great fun, and I hope you'll find that there's tremendous satisfaction to be had creating and crafting your own little corner of the internet.

As you begin to hone your podcasting skills, you'll find that you're also taking a remarkable learning journey. It's one that I think will enhance the way to sense and think about the medium of sound. If you are a musician, you'll already know what I mean. Those of you who can play (even if it's only a few chords on the guitar) know that you listen to music in a qualitatively different way to those don't play. The very act of learning an instrument teaches you to become an active listener and a critical analyst of sound. How is that musical piece orchestrated? How are the harmonies arranged, what technique is that soloist using? What melodic elements hold your attention? As well as just enjoying a musical number on its own merits, you can apply a critical ear to the music, and I would suggest appreciate a work in a much more profound way than the casual listener. The same principles apply when you begin to podcast.

Jack Herrington (2005) agrees with this interpretation. In his text Podcasting hacks: tips & tools for blogging out loud, he considers that there are four elements you should critically examine:

Podcast Structure: Analyze content for recurring or format elements used to keep the listener engaged with the podcast, and to motivate the listener to return for future elements. Is the "interesting stuff" (p.51) at the beginning, the middle, the conclusion, or distributed throughout the pod cast presentation.

Technical Elements: Podcast should take advantage of appropriate Web 2.0 and multimedia components to be effective. In some instances, this can mean a voice-over narrating a story very simply. In other contexts, a podcast may take advantage of music, wildtrack, multiple voices, and sound effects.

Content: Try to understand what holds your attention. This is especially vital: according to Herrington, it's what "primarily keeps people coming back" to listen again. The author suggests that

"When something moves you, listen to it over and over to figure out what is keeping you engaged."

(p.52)

Next time: Fundamentals of Digital Audio Editing

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New E-Learning Curve’s Other Podcast episode release:

In Part 6: The Flying Boats at War

During World War II, the civilian airlines of the Allies continued to fly, though perhaps the nature of the passengers had changed. As the US, Britain, and their allies prepared for the invasion of Europe,

In this episode, Chief Operator of Launch Operations Frank Buckley describes working on the flying boats during the War, the hazards that the aircraft encountered, searching for the German battleship Bismarck, and the excitement of the night-time take-offs and landings.

Click here to listen to the podcast (MP3, 11MB).

Click here to view the transcript of this podcast (PDF, 24K).

Even though this is an e-learning blog, the observant among you will notice that the podcast isn’t about e-learning. That’s OK – the point of e-learning is to provide training professionals with a means of creating and distributing content that enables people to acquire information, knowledge, skills, and expertise on a diverse range of subjects: as e-learning practitioners, it’s our job to facilitate this process.

___________

References:

Herrington, J. D. (2005). Podcasting hacks: tips & tools for blogging out loud. O'Reilly Media, Inc.

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Podcasting for E-Learning: Digital Audio Basics

Really exceptional podcasts transmit a sense of "being there."

Well-designed, planned, narrated and produced audio content has the facility to engage the audience and transport the listener, providing the right cognitive environment for learning or entertainment or whatever goal the podcast seeks to achieve. As the old story goes, “there are better pictures on the radio.” Denis Nowlan, Deputy to the Controller for BBC Radio 4 describes this as

the wonder of radio [and sound] …the conjuring of magical sounds, Prospero-like, out of the silently teeming air. And the sense of joining, instantly, with a vast community of listeners.

(2005)

Of course, this cognitively experienced sense of “being there” is a completely artificial construct, none more so when you consider audio podcasting. The journey the podcaster takes us on is based on nothing in nature; that is, a narrative transmitted as binary data: electronically-mediated zeros and ones.

I will discuss this phenomenon in detail next time, but for now, read on…

Digital audio is actually very similar in concept to motion film, where a rapid series of still photographs make up a “motion picture.” Digital recording reproduces audio signals by taking many still “pictures” – or samples - of an audio waveform and then reconstructing the waveform for playback digitally (see Figure 1).

Figure 1. Digital Sampling of Audio Waveform
[Click to Enlarge]

In film, the number of still images (frames) we move through the projector per second improves the smoothness and quality of picture we see. Similarly, the size of the film's light-sensitive crystals in each frame determines the visual resolution of the image - and we all know movies look better in 70mm as opposed to the 35mm or 16mm film.

In digital audio, an analog signal is typically sampled 44,100 times a second. Each sample is created by taking a "snapshot" of the amplitude (or strength) of an analog audio signal at a particular moment in time. and converting that amplitude into a binary number.

The number of samples contained in each second of audio is called the sample rate. The greater the number of samples per second, the greater the resolution of the audio signal.

Let’s return to the film analogy: the faster the film rate through the camera, the better the ability of the film to pick up motion. For example, if you crank a film camera too slowly, then motion past a camera is not smooth since the frame rate does not capture enough frames in a given amount of time to stop the motion from appearing to jump or jerk - too much action happens in front of the camera "between frames" for the motion to appear natural.

Time for an example: The resolution of an audio CD is 16 bits and the sample rate is 44.1KHz. This means that the audio is sampled 44,100 times a second and a series of 16 zeros and ones is used to define the amplitude of the waveform at each of those 44,100 points.

This resolution – commonly called “CD Quality” and should be your baseline for recording a podcast. When recording voice-over narration, capture all of your audio at 16 bit, 44.1KHz, in mono using the WAV format in Windows, Au format for Unix-based systems (like Linux), and AIFF for Apple Mac.

More...

__________

References:

Nowlan, D. (2005). Radio: where the pictures are better: Denis Nowlan speaks for the medium which leads you by the ear. [Internet] Available from: http://findarticles.com/p/articles/mi_m0KZH/is_1_19/ai_n15928065/ Accessed 12 August 2009.

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Martin Dougiamas says: Moodle 1.9 now released! Hurrah!!

Like the man in the title said, Moodle 1.9 has been released.
Headline features include:

• Gradebook - Completely rewritten from scratch for speed and flexibility. The new gradebook consists of plugins for reports, imports and exports. There are a number of standard reports which are useful for graders, students etc. The grader report allows you to treat the gradebook much more like a spreadsheet with manual editing, calculations, aggregations, weighting, locking, hiding, textual notes and so on.
  
  
• Outcomes - You can also now develop a list of expected outcomes (competencies) and connect these to courses and activities. You can even grade against multiple outcomes at once (i.e. Rubrics).
  
  
• Events API - The new Events API provides a way for any code to "hook" into events in a clean, loosely coupled way. A lot of events in Moodle (such as adding a user or a course) now trigger events that developers can hook into.
  
  
• Scalability and performance improvements - A complete overhaul of the Roles implementation for correctness and scalability. Large sites with thousands of courses and users now load quickly and behave well under heavy traffic, thanks to reworked code for Roles. Additional boost for sites using PHP pre-compilers and significant improvements in the database access code for all databases. Many other parts of Moodle have been optimised to cope better with large numbers of courses and students. Overall performance is very noticeably increased.
  
  
• Moodle Network - Moodle 1.9 and Mahara E-portfolio v0.9 now do transparent Single Sign On - one to one, one to many, many to many. Students can maintain their personal E-portfolios in Mahara.
  
  
• Tags - Allows users to describe their own interests in terms of tags, which creates interest pages around those tags, bringing information together from a variety of sources (Blogs, Flickr, Youtube etc)
  
  
• Improved question bank - Allows questions to be shared by the whole site, a course category, a single course, or be kept private to a single module. More control over who can do what to each question. Improved file management for files linked to by questions.
  
  
• Notes - Detailed notes can be kept about individual users (for example teachers might want to keep and share notes about students in their class).
  
  
• Bulk user actions - Administrators can perform bulk user actions, such as the mass deletion of user accounts. Extended features in the bulk user upload script to allow generation of user fields based on templates.
  
  
• Custom corners theme - Beautiful and curvy (in all browsers).

Find out more here [links to Moodle.org]

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Constructivism Pt.1

In her comprehensive reference text Psychology of learning for instruction, Marcy Driscoll describes constructivism as having

…multiple roots in psychology and philosophy, among which are the cognitive and developmental perspectives of Piaget, the interactional and cultural emphases of Vygotsky and Bruner, the contextual nature of learning, the active learning of Dewey, the epistemological discussions of von Glasersfeld and the paradigm and scientific revolutions of Thomas Kuhn.

(1994, p.375)

Constructivism is an approach to learning based on the premise that cognition, or learning, is the result of mental construction: it is an active process in which learners construct new ideas, skills and behaviours based upon their prior and current knowledge, behaviour and skill assets. The learner transforms information, constructs knowledge, and makes decisions based upon extant cognitive structures or mental models. These cognitive structures - what Roger Schank calls “scripts” in his Dynamic Memory Model (1982) - provide meaning and organisation to experiences and allow the individual to go “beyond the information given” (Bruner, 1974). Even though there are numerous interpretations of constructivism, several central concepts inhabit all constructivist theories. Cunningham and Duffy (1996) identified two major similarities that are the foundation of all constructivist thought. They are that “learning is an active process of constructing rather than acquiring knowledge” and “instruction is a process of supporting that construction rather that communicating knowledge” (1996, p.172).

References:

Bruner, J. S. (1974) Going Beyond the Information Given. New York: Norton.

Cunningham, D. J. & Duffy, T. M. (1996) Constructivism: Implications for the design and delivery of instruction. IN: Jonassen. D. H. (Ed.), Handbook of Research for Educational Communications and Technology (pp. 170- 198). New York: Simon & Shuster Macmillan.

Driscoll, M. P. (1994). Psychology of learning for instruction. Boston, MA. Allyn & Bacon.

Schank, R. (1982) Dynamic Memory: A Theory of Reminding and Learning in Computers and People. Cambridge University Press.