34. Recorded Sound properties

Figure 34.1
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Figure 34.1 shows a Recorded Sound box and its properties; Recorded Sound is a bit of a misnomer, as non-recorded sound can also be used.

The properties of a Recorded Sound box are as follows:

• Raw sound file This should be the pathname of an uncompressed .AU, .AIFF or .WAV audio file; you can search for and select such an audio file using the search button to the right of this edit field. In figure 34.1 we have chosen a file named Cymbal.wav, which happens to be a sound generated using Kangas Sound Editor that has been uploaded to Freesound.org and also the KangaSound XML listing page. For a song track this could be a file containing the singer's vocals. Dealing with differing audio formats isn't a strong point of Kangas Sound Editor, so you may need to use another tool such as Audacity to convert a supplied audio file to the uncompressed .AU, .AIFF or .WAV audio format that Kangas Sound Editor can understand.
• Raw sound file start ofs This is the start offset in seconds from where you wish to extract sound from the raw sound file. In figure 34.1, a value of 0.5 has been entered in this field; the first half-second of the raw sound file Cymbal.WAV is effectively ignored.
• Duration This is the duration in seconds of audio you wish to extract from the raw sound file. In figure 34.1, a value of 2 has been entered in this field — just two seconds of the raw sound file Cymbal.WAV is used.
• Channel selector The sound associated with a given Recorded Sound box is mono, but a raw file that contains stereo sound can be dealt with. In figure 34.1, the Left radio button is selected for this field, which corresponds to the left channel (and ultimately speaker) of Cymbal.wav. If you want to also use the right channel for a given raw sound file, then setting up another Recorded Sound box, probably on another track, would make sense.
• Amplitude ext./mult. This extent/multiplier field determines the range of amplitudes for this Recorded Sound box. It can be used to make the audio for this Recorded Sound box more prominent (relative to other sounds on this track) for values greater than one, or less prominent for values smaller than one.
• Amplitude graph Entering/selecting a graph into this field can be used to vary the amplitude over the duration of this Recorded Sound box: the graph's y-values determine how much the amplitude varies, and the graph's x-values determine the exact timing of amplitude changes.
• Compute method The Original method handles .WAV audio files only, and may produce different results to the New method due to subtle differences in implementation. The New method handles .AU, .AIFF and .WAV audio files, and uses Java audio libraries in its implementation. The New, fallback to original on error method will attempt to use the New method first, but if a problem is encountered will attempt to fallback to the Original method.
• Keep intermediate file Ticking/checking this checkbox will result in an intermediate file for this Recorded Sound box being kept. Having it checked can save time if computing the Recorded Sound box is slow, and you are repeatedly doing a Compute kwik operation at a higher level (e.g., on the track that contains this Recorded Sound box).

Figure 34.2
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Figure 34.3
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Figure 34.2 shows the Duration plus other statistics dialog that appears when the Duration button is clicked for a Recorded Sound box when the compute method is Original; figure 34.3 shows a similar dialog that appears when the compute method is New. In addition to the usual information (see page 22), some details of the raw sound file is shown; this information may be useful when setting the properties of the Recorded Sound box.

Notice that the (orange-bordered) Recorded Sound box is contained within a (red-bordered) Repetition Group box. Although it isn't used in this example, this could be used to add a reverb or echo effect to the recorded or non-recorded sound pulled in. Repetition Groups (see page 20 of this tutorial) can be used to vary the volume and/or interval between successive repetitions, thus creating such an effect. For an example of a reverb effect created using this technique, see the entry for Reverb effect on piano notes in the KangaSound XML listing page