The ability to create and edit audio files, and link them into HTML documents, is important for language students. Increasingly, research papers in the Humanities are including speech samples, ranging from dialect specimens to examples of interpreting solutions to spoken instructions for visually-challenged users of standard web material. Music files are edited similarly to speech files, and are also being increasingly in academic work.The screenshots above show the Windows XP Pro version of Sound Recorder still used on many UTA computers.
The pull-down menus in images 2-4 give an idea of the greater capability of the software.
Also demonstrated in class will be the open-source Audacity software, downloadable from audacity.sourceforge.net. Audacity is considerably more sophisticated, enabling both the basic functions of Sound Recorder and advanced audio editing well beyond the PK5 requirements. Among its advantages are much longer file length, the ability to work with MIDI and MP3 files as well as WAV files (see below), and 'wavetable' editing of audio files. (When using Audacity to save files in MP3 format, the lame_enc.dll file available here must be downloaded and added to Audacity when you are prompted to do so. It is recommended that lame_enc.dll be put in your computer's Windows folder.)
About WAV, MP3, WMA and MIDI FilesWAV, MP3 and MIDI are the three most common digital formats for audio files. Of these, WAV represents the highest audio quality, though as a result also the largest filesize. "WAV" is an abbreviation for "waveform audio." Most commercial CD music recordings are in WAV format. The WAV format is "uncompressed"; e.g. it has 100% of the digital signalling of the audio event which has been recorded. MP3, on the other hand (with the abbreviation derived from "Moving Picture Experts Group"), is a highly compressed digital format, in which signals which are not normally audible to the human ear have been removed in order to achieve a smaller file size.
WMA ("Windows Media Audio") is another compressed digital format, similar in function to MP3. WMA is a proprietary format of the Microsoft Corporation. WMA, WAV and MP3 all record sound as digital 'waves,' which may be either speech or music or a combination of these.
MIDI, in turn, is an acronym for "Musical Instrument Digital Interface." MIDI files are produced by music synthesizers and other digital music production devices. MIDI files are always musical. As they only represent key-tone data (as opposed to sound 'waves'), they are usually quite small in size. Due to their compact filesize and quick loading, MIDI files are often used as background music for themed HTML and Powerpoint presentations. Thousands of MIDI files are downloadable free of charge from the internet for such purposes, with one of the largest download sites being MidiWorld.
Examples of Recording, Editing and Linking Speech FilesOnly a simple recording is needed to demonstrate your ability to create a speech sample. The recording need not be more 'profound' than the 'rain in Spain' recording made in class by John (cf. another version of this in 'WAV' format via Windows Sound Recorder and a Plantronics digital microphone), (though it can be more sophisticated if you wish). With your audio file, identify the voice(s) in the recording, and tell what the format is and what software was used to produce it. The file may be either linked or embedded). The 'identification' of the file should be similar to either (a) the in-text description of this paragraph or that of the (b) embedded audio link below.
The filesize of the linked WAV version of 'Rain in Spain' above is 429KB. Compare this to the same file converted to MP3 format as embedded in the table above, which has a filesize of 79KB. Is any any audible difference in quality? Generally for web files (particularly for speech files), MP3 would be the preferred format, as one gets a considerably smaller and faster-loading file with little noticeable "loss" of relevant information. However, depending on the quality level chosen for a WAV recording, it is possible there would be little difference between WAV and MP3 recordings of the same event.
Audio files can also be coded to auto-start as soon as a new web page is loaded. Any type of audio file can be used for this purpose, and the file can be coded to play only once, or to "loop" more than once, or even infinitely (or at least until one moves to another web page). An example of such auto-start files is Max Pechstein's Dancers. This uses the coding <bgsound src="dancers.mp3"> which is put as one of the first lines of code once the "body" segment of the HTML coding has begun. The coding means you would like a "background sound" to play, and the "source" of that sound is the filename you identify. This coding will play the file only once ("dancers.mp3" is a large MP3 file, so with slower internet connections there may be a delay in its starting).
However, the simple coding given above may not work with all web browsers. It should work with Internet Explorer and Firefox, but not always with other browsers, such as Google Chrome. An alternate way of coding which should work with all browsers is to use the <embed> command. An example of this is Max Pechstein's Dancers (Version 2). Here, the HTML command used is <embed src="dancers.mp3" autostart=true loop=false hidden=true>. This tells the browser to use an "embedded" audio control console to play the file, in auto-start mode ("autostart=true"), played only once ("loop=false") and with the console itself being hidden from the user ("hidden=true").
One may also "play it safe" by combining both codings in the same page,
leaving it to the browser to choose the one is recognizes. In this case
the 'combination' coding for the two "Dancer" examples above would be:
Differences Between Browsers in How Audio Consoles Will DisplayWhile the coding above will work with all standard web browsers, the way the consoles will display depends on (a) which browser you are using and (b) which audio software that browser uses as its default.
The key difference is the default audio software the browser uses for particular types of audio files (WAV, MP3, WMA, MIDI, etc.). The Firefox, Safari and Google Chrome browsers by default all use Quicktime to play audio clips; Internet Explorer prefers Microsoft Media Player, although Quicktime or other audio players may be set as the default instead.
With Google Chrome, however, if Microsoft Media Player is set as the default for MP3 audio files, and there is more than one audio clip in a particular web page, the browser will become confused and play all of them simultaneously. If the computer's audio software default for MP3 files is set to Quicktime, this problem will not occur. Thus, if students experience problems similar to this, the solution may often be conflicts between your computer's default audio settings and those the browser you were using was expecting, rather than a problem in web page coding as such.
Below are examples of how the console above-right displayed on the same computer with identical settings using Internet Explorer 8 (left) with Microsoft Media Player as the default audio software, and Mozilla Firefox 3.0.4 (right), which uses Adobe Quicktime as its default audio player. [The images are screen-shots, in which the original captions also appear.] The IE8-Windows Media console is differently-colored and thicker than the Firefox-Quicktime console, with slightly different controls. Notice also how the Firefox browser has separated the console and caption with additional space, and how the caption font displays differently. [Bear in mind that (according to the paragraph above this one), if IE8 had been set to use Quicktime as the default audio player, the consoles would display similarly to the Firefox/Quicktime example below: e.g. the default audio settings will supercede the preferences of the browser itself.]
(NB: The two consoles above are only images; they are not functional!)
Auto-start Files and Timed Transfer From One Page to AnotherTwo more examples of auto-start files are linked below. These use brief home-made speech files in WAV format, which should load and play instantly (without the possible time delay of the large MP3 file in the Dancers page(s) above). The "embed" technique of coding the auto-start was used on both of these pages.
These files also illustrate automatic timed transfer from one web page to another, which may be useful for auto-play time-sequenced web materials. In addition, the second of the two pages gives an example of coding for "phased" page entry and exit. Click here to start the sequence (which will return to this point in this file).
Special Coding Needed For MP3 Files in Google Chrome!NB: The basic auto-start feature shown above will work with all audio filetypes in all recent versions of Internet Explorer and Firefox, but not for example with MP3 files in the Google Chrome browser (at least through version 10, February 2011). [WAV files will work properly; the problem applies only to MP3 files.]
However, the 'alternate' (<embed src= . . . ) coding above does work for Google Chrome as well. Thus this second version is recommended for autostart coding unless you are certain that those viewing your pages will have a compatible browser for the basic coding. [It may be useful to include a note in your auto-start pages suggesting what browsers will work, in case those viewing your auto-start files are using non-compatible browsers.]
Google Chrome will also not play audio consoles using MP3 files with 'standard' coding that works in IE and Firefox. However, a solution to this is to add the additional parameter type="audio/mpeg" to the auto-start or console box commands (see examples in the html source code for the MP3 'Rain in Spain' console above and the 'Millionaires' Row' MP3 file consoles below). This additional parameter will not affect the console functioning correctly in Internet Explorer or Firefox. Note also that the Google Chrome browser always uses Apple's Quicktime software to display consoles and play MP3 audio (no matter how your default audio settings have been set otherwise).
Editing an Existing Audio File and Using Visible Embedded ConsolesBelow are two illustrations of editing existing audio files. Both give an original file and an "edited" extract, with an explanation of what has been done. This also illustrates how the PK5 exam option could be done (although clickable links may also be used for the exam requirement in place of embedded consoles).
The first example edits an extract from the Rev. Dr. Martin Luther King Jr's 28 August 1963 "I Have a Dream" speech, delivered on the steps of the Lincoln Memorial in Washington, D.C. (source American Rhetoric: Top 100 Speeches see the Wikipedia entry for background on the speech). The "edited" version has been shortened further to isolate the "I have a dream" sentences by removing the parts of the speech before and after these.
While the same examples could also have been given simply as clickable links (as with the 'rain in Spain' example toward the top of the page) using embedded control consoles allows the page user to pause the file, adjust the volume, fast-forward or -reverse, or jump to the beginning or end of the file, as well as providing a 'progress bar' of the file length. The same controls should be available from your media player in the separate window opened via clickable links, but embedded console controls allow the reader of the page to stay within the same window, and are especially useful when . Further detail on embedding consoles will follow later in this file.
The second example below uses two extracts from a 5-minute MP3 audio tour demo file of the "Millionaire's Row" neighborhood in New York's Manhattan district, originally in the Tourcaster website. Say that you want to use the tour guide's voice as an example of "New York dialect" in a paper on American regional speech. The demo file begins with a Tourcaster promotional blurb which is not useful for your paper. Likewise 5 minutes is too long; all you need is a brief coherent segment to illustrate the distinctive tonality and other speech characteristics of the tour guide's voice. The following illustrates how this might be done.
Further Detail on the <EMBED> TagTo summarize, the "embed" (<embed>) tag allows you to insert audio into your Web page using an audio "console" or "control box" so page users can control playback of the audio. Examples of audio consoles are given above. The "embed" command is supported by the newer versions of all major browsers. It may be used either for invisible playing of auto-start files, or to produce visible user-controllable consoles.
A. Coding Options for Embedded Auto-start FilesThe example given above to embed the auto-starting "dancers.mp3" was:
<embed src="dancers.mp3" autostart=true loop=false hidden=true>Based on this example, other coding options could include:
B. Coding Options for Visible Embedded Audio Consoles