What are the units of the channels in the result of readWave() in the tuneR package?

Question

I am beginning to process my own .wav files, but am confused about the resulting object of the readWave() function in the tuneR package. The following basic walkthrough is a good reference for answering my inquiry:

http://samcarcagno.altervista.org/blog/basic-sound-processing-r/?doing_wp_cron=1527373182.3890509605407714843750

The values in the left channel piece of the output of the readWave() function get converted in this example. I'm interested in learning the original units as well as the ending units after this conversion.

Thanks!

Answer 1

It looks like the author answered this question in the comments of the same page you link to:

The unit of measurement is arbitrary. If you play out the WAV file the actual RMS level will depend on your equipment (soundcard, volume settings on your computer, speakers/headphones, etc…), so there is little point trying to attach an absolute measurement unit to the amplitude values of the waveform.