Sound Recording
This page is about audio recording, including constructing narration clips for short vodcasts. It deals with the production chain from a source such as microphone all the way to the final product. Access to simple tools that first time users (such as primary and secondary school students) can very easily use, as well as information on how to move the recorded files along the production chain to a Non Linear Editing(NLE) platform such as iMovie and combined with video clips are discussed.
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A Sound Record 1
RecordPad is a nice little " does one thing and does it well" application from NCH. It is extremely easy to use and most importantly saves the resulting files automatically in a set location /startUpDisk/Users/<user>/RecordPad which is easily accessed from the menu or playlist button. That is you don't need to navigate. The files can then be played with a double-click using iTunes.
On launch it is ready to record! Click the record button, speak, make sounds, then click the stop button. it's that easy.
You have the option to save as WAV, MP3 or AIFF. It can also be set up to send a recording via e-mail, remotely to an FTP site or automatically to a disk mirror (on LAN). It provides sound cues for start and stop recording. After that you can import the files into an audio player such as iTunes, or a composing application like GarageBand or a video production application like iMovie. It would be excellent for making short sound clips to narrate Keynote presentation slides without text. Just for something different…
RecordPad is excellent for first time users to record live sound clips. It uses CoreAudio functionality so that you can patch different sources, such as from an external (studio) microphone or hardware interface. It's free.
A Sound Record 2
The next step up is Rec 2.1.3 from Polyrythmic. This has a slightly more complex interface, with a display of the loaded/recorded audio waveform. It also allows you to easily edit the captured audio (by selecting the part of the waveform desired) before you save it as either a AIFF or WAV file. You can also load existing files to edit. A 120 beats per second(bps) metronome function is available but you can't change the bps. It also uses CoreAudio functionality so that it can record audio from any available CoreAudio source in either mono1, mono 2, stereo format. It's free and works with SL 10.6.2.
A sound engineer's delight
Audacity is a sound engineers delight because (on a Mac) it can
- capture sound from any physical CoreAudio source (microphone, line). The quality depends on the quality of the chain {microphone, real-time transcoder- analogue to digital} and can vary considerably.
- process the captured stream
- save the processed stream
Until I had a very good look at what Audacity has to offer I was a bit dismissive of it as an easy to use application. It is not very easy to use- except for capturing, basic cutting and saving of audio files, but it makes up for that in three ways: it's free, its cross platform, and it has a plethora of processing capabilities.
Besides the simple process of capturing audio and editing it, Audacity on the Mac also honours CoreAudio capabilities, and AU capabilities like Garageband. It has amazing technical audio processing capabilities as well.
In some ways this is the "raw" version of GarageBand. if that was not enough, it also has a scripting language called Nyquist for constructing plug-in modules. Being a derivative of LISP gives Nyquist a steep learning curve. There is another interface called SAL that is more procedural (and easier to work with) than LISP.
It would be an incredible advance for the Mac OS X version if the functionality of Nyquist was to have an AppleScript interface since technically, AppleScript and Nyquist are very similar.
Besides its obvious use in capturing and processing audio in music classes, Audacity would find uses in Science lessons, where it can be used to generate sounds with specific features. This would be particularly useful in describing Frequency Modulation and Amplitude Modulation in Physics and General Science classes. There would also be application in 4 Unit Mathematics classes, where the sensory medium for representation of a mathematical concept would be a sound stream rather than a visual graph.
Some useful sites. NOTE: Audacity looks almost identical on thePC and Mac.
- Complete set of Audacity Tutorials for Podcasting. Requires latest Adobe Flash Player.
- Podcastingusing Audacity and iTunes '09 ]
- includes some good tips for Adobe Presenter, iTunes U, iMovie '09 and a short guide to Storyboarding.
Let a thousand sounds blossom
Soundflower is a sound routing extension for MacOS X. It presents itself as a real-time CoreAudio input/output virtual mixer. Anyone interested in live audio mixing would find this interesting.
It has two modules: a 2 input/2 output module and a 16 input/16 output. Both appropriate software applications and hardware devices can be source or destination endpoints for soundflower.
For example you can route an external microphone signal from say a USB headset dongle, through a soundflower channel, while at the same time routing sound from an application. Streaming music from iTunes comes to mind here. The end result could then be passed to another application for recording- for example Quicktime Player 10. This is about as simple a Podcast set as you could imagine.
This is different from using GarageBand in that you are managing the mixing of live audio feeds to create an audio stream from actual devices rather than editing existing audio files.
Another very simple set up would use a USB headset dongle feeding an input to a soundflower channel. A second microphone could be connected to the standard microphone input on the Macintosh and passed to another soundflower channel. Thirdly, the built-in microphone could feed a third soundflower channel. Soundflower then acts as a 3 microphone mixer.
The resulting mixed stream could then be simultaneously fed out to the USB headphone dongle, a headphone set connected to the headphone socket of the Macintosh, and input to Garageband for recording as a track. To do the same using an external hardware mixer would cost at least several hundred dollars.
Of course the external system would be easier to use and would provide more features such as specialised sockets and connections (e.g.. TRS/ XLR, Digital Audio/ with USB or Firewire control). Soundflower is GPL2 (freeware).
For more information
Audio Pass Through on Mac OS X
The latest versions of Mac OS X do NOT have an in-built option to allow "soft play through" or Pass Through, which is a form of looping input to output to monitor a live audio stream.
Fortunately, LineIn 2.0.3 by Rogue Amoeba Software provide a simple and free solution to this problem. It honours CoreAudio and works with Mac OS X 10.6.5. Just one of those, does one thing and does it well, really.
