unknown units in wave-class 'left' slot from readWave object output

[Danielle Fradet]

Hello,

I know this is a seewave discussion group, but I am hoping I can get my question answered here as I use the object from the readWave function for seewave functions. 

I am reading in 16 bit PCM single channel .wav files with a sampling rate of 24000 hz into R with the readWave function. When I view the readWave object, the acoustic data looks like it gets read in correctly, but I cannot find what units/format the @left integers are in. When compared to Matlab, the same @left integers are stored as volt measurements. I compared the two integer sets, and R's @left integers are scaled exactly 2^15 times larger than the Matlab's output.  To me, this indicates some sort of binary system related to the 16 bit .wav file, but again, I have found no information online or in the tuneR package description as to what the .wav file integers are getting stored as (pressure, voltage, etc). 

If anyone could tell me the default numeric unit for the left slot in wave-class I would be greatly appreciative.