Introduction
Audio production is important both as its own medium and for use with still and moving images to create slide-shows and videos. Production that is centered around human voices does not require sophisticated equipment or technical skills.
Podcasting, originally a tendy idea (if not a large-scale reality) has been supplanted by video or vodcasting in the age of Youtube. As a result there are not as many tools, web-based or otherwise, that support the production, editing and distribution of audio. The premier tool for amateur (and cheap professional) producers of audio is Audacity. This free, open-source software supports recording or importing audio, and provides a wide range of tools for manipulating and editing this audio.
In the development of audio for education, whether you use Audacity or any other tool, there are a series of steps that should be followed to make the best media possible for the resources and time allocated.
Develop
The first stage in the process of creating any piece of educational media is to develop an understanding of what is to be produced. This includes identifying the learning objective you wish to support, the media that is most likely to support this, and the principles or strategies in designing this media that is going to be most effective in supporting your learning objective.
When you have identified a need for audio in your lesson the first step occurs befor you set up your first microphone. That is to plan what audio you need, what information you want to supply as an audio narrative (or series of sound effects – though this is much rarer). A coincident consideration is what genre you want to use in conveying this auditory information. Will your text be spoken in an unemotional, detached voice like a news reader or documentary narrator? Will you use an interview format, or a discussion format. Perhaps your audio can take the form of a straight-up dramatization or perhaps sarcasm, irony or some other popular comedic approach will allow you to amplify the meaning you hope ot get across. Regardless you must make these decisions before moving on to plan for the production of your media.
Plan
While you strive for an unscripted and natural quality in audio files you create, you really do need to create a script for your audio pieces. This may take the form of a complete script or a set of bullets but it must be sufficient for those that are going to be recorded to comprehensively accomplish your goal. You may find that after starting and practicing with a verbatim script, you are able to move a to a more ad-libbed performance in the actual recording. If your plan is to engage in a discussion or interview-style audio piece then you should have planned your questions and possible follow-up questions to lead your subect or discussion where you want it to go. In interviews it is often best to share your proposed questions, or at least your major questions with the interviewee ahead of time.
The site for recording your audio requires some forethought as well. An outside or public environment may be tempting as a way of adding reality to your production but you should consider the effect that background noise and loud interrupting noises may have on your recording. Even in an interior space you should consider your ability to keep interruptions out and bakcground noise to a miniumum. You should turn off telephone ringers and notify co-workers that an audio recording is taking place. Also take care to listen for background noises like ventilation systems that may have melted into your perceptive background but that will become prominent in your new recording.
The equipment that you select and configure to record your session must also be tested prior to the actual recording. The first item to decide upon is the media and device you will use to store the original recording. Most commmonly a computer can be used to store audio in digital form, utilizing a program like Audacity as the recording software. Other stand-alone tools such as hand-held digital audio recorders can be used. The quality offered by these vary but often are linked closely to the quality of the microphone used.
Your microphone(s) is likely the most important technical factor in the quality of your recording. Many laptops and after-market webcams include microphones that range from suitable for voice recording to inaudible for any function. A computer headset with microphone can often provide a reasonably good quality of sound recording though it is only practical for a single voice. Passing a headset between speakers introduces awkward delays and holding the headset microphone in your hand leads to poor quality input as it is variously held too close and too distant from the mouth.
A microphone purchased specifically for making digital recordings can be a good investment for an educator who intends to make many such pieces over time. Two technologies and two configurations should be considered. While there are many types of microphone out there, educators should consider the traditional hand-held microphone and the smaller lavalier microphone which is attached to the speaker’s clothing. Additionally, these microphones can be hard-wired back to the recording device or they may be wireless. While wireless microphones can be more expensive they provide greater ease of use and flexibility. Alternatively cheaper wireless microphones may be susceptible to interference from fluorescent lights or other electronic equipment.
The settings for recording your audio should be decided ahead of time based on the intended purpose and final destination of your file. These settings, file type, sample size (or bit rate) and sample sample rate, will impact the quality and file size of your recording. For a simple introduction to digital audio, including sample rate and sample size visit the first section of the Audacity online tutorial at:
http://www.audacityteam.org/help/documentation/
File formats for audio range from lossless varieties intended for archiving and working with high fidelity recordings to compressed formats that are best suited for streaming and downloading over the internet. There are several audio tools that will produce audio in the .wav format. This is widely supported and can be worked with to produce a file that is ready for distribution. To distribute audio over the internet, whether streamed (a progressive download that lets you start listening before the entire file is downloaded) or for download, the most common type and the one that is most useful to educators is the MPeg Layer 3 or .mp3 format. The MP3 format provides good compression (reduction of the file size for a given piece of audio), reasonably good quality and is widely supported by both production and distribution tools. Files produced in the .mp3 format are naturally streaming without further development work or specially configured web hosting. Other formats have applications and uses where they are superior to MP3 but as a beginner and, until you have reason to use a different file type, I suggest that you consider the MP3 format as your standard.
If you are creating a complex or high fidelity piece of audio that will be used for a long period of time it may be useful to record and store in a lossless (without compression) format such as Waveform Audio Format (.wav) and then export your audio file for distribution as an MP3. If you are producing something for now that is unlikely to be mixed extensively or kept for posterity then recording directly in MP3 is fine. Similarly the settings for sample rate and sample size will likely be different depending on your purpose. A 16 bit sample size and a sample rate of 22 or 44 thousand hertz are sufficient for a clear spoken word file. If you were recording a piece of music you would want to increase these rates to obtain an acceptable level of quality. Remember that in most tools, including Audacity, you can record at higher settings and then decide what settings are suitable for the distribution version of your file. Of course, lower sample size and sample rate result in a smaller file size for the equivalent piece of audio.
Produce
If you’ve planned for your recording session, both technically and for the narrative you hope to capture, then recording will be the simpler part of this process. You should be sure to alot sufficient time for setting up and briefing your audio subjects as well as time for breaks, repeating portions and accomodating last minute revisions.
As you record you should keep running notes of the timing of portions of audio you will want to edit or treat separately. If a subject makes an error ask them to pause and start again from the last correct segment. Note the time of the error and you can edit it out easily later. Before you pack up make sure that you’ve recorded several seconds of silence in the setting of your recording in case you need to add some silence between elements of your recording. Most audio editing programs will insert silence but this complete silence will be obviously artificial compared to the muted background noise that populates the space between the spoken pieces of your recording.
You can record your audio using various programs that might be included on your system, downloaded for free, or operated over the internet. Most current Mac systems will have Garage Band installed which, while rather complex, can record high quality audio. Audacity is a free recording and editing program that can be downloaded for Mac or Windows machines. I would recommend downloading and learning to use Audacity. On the download site you will find instructions to also download and install the LAME file required to produce MP3 files. Be sure to take this step as well.
Edit
Even the perfect recording session will need to be reviewed for a suitable sound level and inadvertant popping or interference. Make sure that you create a copy of your original recording for editing with your audio software. Some software will alter the file that you are editing while others (like Audacity) will mark up your edits separately from the original file.
If you have only one microphone and you were asking questions or interjecting in the recording you may want to re-record your questions and integrate them into the final version. If you do this make sure that you stick to your original phrasing and resist any temptations to edit what was said in the original session.
Audio that is longer than ten minutes, especially if it covers separate topics, will benefit from being broken up into shorter segments. This can make your audio resource more flexible and allow students to concentrate on discrete points before moving on when they are ready. You may also want to edit your recording to take out extraneous elements. Your speaker may have provided too much detail or wandered off topic. Take care in your editing that your end product is still coherent and that you haven’t altered the speaker’s meaning. In some cases you may want to edit a recording down to the essential points that students need but also provide access to the original recording for those seeking more depth. This is also a way of making an interview process more transparent.
Once you have completed your editing you need to export your audio file in a format suitable for your method of distribution. On the internet MP3 is a widley acceptable format for audio and I would recommend this unless there is a reason to seek an laternate format.
Distribute
Finally you have to get your audio to your audience. Two methods are typical on the web: file download and streaming audio player. If you distribute your audio file as a file for download you are expecting students to download the entire file and then play it using an application like Quicktime or Windows Media Player on their own computer system and outside of any course website or context. A streamed audio file plays in a small application embedded directly in your course web page. This file either inherently, or through a specially configured web server, is delivered so that the audio can start playing once a small portion has been delivered. I would recommend using both distribution methods for most audio files. An embedded player with a link for a file download closely associated provides the opportunity to associate the audio with a graphic and for the student to retain a copy for later review.
A hosting space for your audio files will be an important resource for you as an educator. You should consider a space that makes it easy for you to place and edit files. This may be an institutional server or a space provided by a third party either for free or for a small fee. The Internet Archive offers free hosting for audio files as long as you can leave them as public domain files (anybody can do anything they want with them). The Internet Archive provides an online upload interface for your files and then displays a link URL and embed code for these files. If you have a commercial space on a server or space on your institution’s server you may be lucky enough to be able to interact with this space as a networked file server. This means that you will place audio (or other media files) in a folder on a drive in the same way and with the same tools as you currently use on your desktop computer. Otherwise you will have to use a different internet protocol called File Transfer Protocol or FTP to move your files to and from your web server space.
Here is an example of a link to a file for download. Note that on WordPress the download link may be converted to an audio playing application.
<a href="http://www.archive.org/download/5StepsForMediaProduction/5steps-media.mp3" title="5 Steps for Media Production" target="_blank">5 Steps for Media Production</a>
Modern standards for media in the latest HTML specification (HTML5) allow for media to be played natively within a web browser without the requirement to install a plugin like Windows Media Player or Quicktime. For audio this works well across all modern web browsers if you use the ‘mp3’ audio format. Here is an example of the HTML5 ‘audio’ tag used to embed a file.
<audio src="http://www.archive.org/download/5StepsForMediaProduction/5steps-media.mp3" type="audio/mp3" style="width:200px; height:25px;" controls>Some text here appears if the browser doesn’t support the ‘audio’ tag.</audio>
This embed code will work for almost all computer and mobile systems. I typically include a link to download an appropriate media player whenever I embed or link to media.
Use the tool below to try out embedding an audio file.
Conclusion
This is a bare-bones introduction to the process for producing audio for learning. In many ways it will be a similar process for developing any type of media. While there are opportunities out there for more specialized training in audio and video production, as an educator your time is probably better spent trying out what you can do with the tools at hand and, after experimenting and devloping your own expertise, begin considering what your next investments in media production will be. At this beginning level there is no reason that you can’t begin to create engaging audio pieces of reasonable quality using web-based and free software and a reasonably priced microphone.