Accessibility at NSW CLIC

(reviewed by Andrew Downie)

Background

Previous versions of Audacity have been popular in the educational field. One benefit is cross-platform support with versions available for Windows, Macintosh OS X and Linux. Other attractions include considerable versatility and the fact that it is free.

As indicated in the heading, the software under review is a beta. Nevertheless, evaluation during the beta cycle indicates a high degree of stability. At the time of writing, the current version is 1.3.11, but new versions are made available relatively frequently as arrival of the final release draws near.

Whereas previous versions were heavily mouse-reliant, version 1.3 provides extensive keyboard support, as discussed further below. For those who prefer or require keyboard to mouse control, this is a significant benefit. The other group to benefit from this version is screen reader users. Whereas earlier versions were largely inaccessible to them, there are now few areas that are off limits. This important aspect of Audacity’s development is also discussed further below.

Multi-track recording

One area where Audacity differs from most inexpensive audio recording software is that it allows recordings to be made on multiple tracks. Audacity has no restrictions on the number of tracks to be created, the upper limit being governed by performance of the host computer. Due to sound card limitations, no more than two tracks can be recorded simultaneously on most computers. Material can, however, be subsequently recorded onto new tracks, while optionally monitoring the contents of existing track(s). An example of using this facility is recording the lyrics of a song on one track and then adding harmony on a separate track. Another example, as shown in the above image, is to use one or more tracks to record a soundscape and provide a commentary on a separate track. Contents of each track can then be manipulated independently. Adjustments may include level (volume), panning across the left-right spectrum and adding any of a wide variety of effects discussed below.

Each time record mode is selected, a fresh track is created. If the intention is ultimately to produce one continuous recording, it is necessary to move the cursor to the end of the most recently recorded track before recommencing recording. With the release of the 1.3 beta, the need to create multiple tracks in this situation has been obviated with the inclusion of an append recording command, which continues recording at the end of the selected track(s). Sections of a recording can also be rearranged in much the same way that text is manipulated in a word processor.

The project model

Material recorded with Audacity is, by default, saved as an Audacity project. This preserves all recorded tracks, including any effects that have been applied. When all editing and sound manipulation is complete, the project can be exported to a standard monaural or stereo audio file. While WAV and AIF files are supported directly, some compressed formats are not due to licensing issues. Encoders for such formats as MP3 and WMA, however, are freely available.

If an existing audio file is to be edited with Audacity, that file must first be imported. After editing, the file can then be exported. Especially if multiple tracks are created during the editing process, it is essential to save the work as an Audacity project until the task is complete.

Editing and applying effects

As mentioned above, whether activating record mode with the mouse, menu or shortcut (r), a fresh track is created. Once recorded, editing of a track cannot be done until it has been selected. This can be done with the mouse or by arrowing to the track and pressing the Enter key (pressing Enter again deselects the track). Importantly, any number of tracks can be selected simultaneously. This is useful when performing tasks such as normalising sound levels across tracks and, in some cases, adding effects. It is important, though, to select only the track(s) requiring a change or unwanted results will occur. Fortunately, in such situations, Audacity offers a robust “undo” facility. A single track can be “soloed”, so that only its contents are heard. Alternatively, one or more tracks can be muted. These features can be very helpful during editing.

The level (volume) of all or any part of a recording can be adjusted. Audacity also provides several tools for compressing the dynamic range of the recording, allowing adjustment when some sounds are originally much softer than others. Fade in/out and cross fade are also available. There are tools for removing background noise. Subject to the nature and severity of the noise, these can be very effective.

Effects allow a recording to be embellished. Some offered by Audacity include reverberation, base or high frequency boost and filtering of various frequencies. For situations where accuracy is preferred to authenticity, the pitch of a singer’s voice or an instrument can also be corrected. For those wanting to listen to a recording at speeds faster or slower than normal, this can be done while, optionally, retaining the original pitch.

Screen reader and keyboard access

Paradoxically, much audio editing software is highly visual in nature. This often involves graphical controls emulating the appearance of those on physical recording equipment of yesteryear. Unlike the controls on that equipment, virtual controls employed in software often require vision and a mouse to operate them. While Audacity can still be used visually, it now also supports keyboard control and Windows-based screen readers very well (it is largely inaccessible to VoiceOver on the Mac). The following is a brief description of its functionality when using a screen reader.

Arrowing up and down the tracks (if more than one is present) results in the screen reader announcing the name of each track. If the track is selected for editing, this is announced. The screen reader will also report if the track is muted or soloed. This information is also available visually. Ctrl-F6 cycles through the toolbar and track view, which makes a number of tasks normally performed with the mouse available to the keyboard. It also provides a relatively convenient means of reading and setting the important time-based position and selection values.

As well as mouse controls, there are now comprehensive menus and shortcut keys. While not all possible shortcut keys are assigned by default, up to 182 can be allocated by the user within Preferences. The software can therefore be tailored to suit individual needs and circumstances.

Some issues

While a reasonable range of effects is provided, some are rather crude compared to other products. That said, those products are not free. A number of additional effects are also available as free plugins, but were not assessed.

Latency is an issue when doing multi-track recordings on Windows-based computers. This can result in the recording on a second track not being synchronised with that on the first. This is due to Windows sound driver software and Audacity provides settings within Preferences to adjust for the problem. Experimentation with settings on individual machines will be required if tracks are not synchronised when played back.

One limitation for screen reader users is that recording level is displayed as a graphic only. Similarly, tools for analysing a recording present information graphically. Some work-arounds are possible, but are less than ideal.

Summary

As a free, cross-platform audio editing program, Audacity has much to offer. It can serve as a simple recorder and is often used as such, but its capabilities go well beyond that. The improved accessibility built into the beta is very welcome.

Since 2008 Audacity has been included in the
Commonly-used e-learning applications and tools in VET, which is a national recommendation for teachers in the TAFE area. The version currently supplied on DER NSW netbook computers is the older 1.26. Many of the above comments, especially those relating to accessibility, are not relevant to it.

Availability

Audacity is available for free download from http://audacity.sourceforge.net.