audiorecorder - no real stereo sampling?

Hi all,

working with the Matlab audiorecorder class I just noticed an issue:

The audiorecorder object is configured to sample 2 channels. After recording getaudiodata actually returns a [siglen x 2] signal vector. However, the second column in this signal vector is just a plain copy of the first one, i.e. no real stereo signal is recorded.

Using the same mic input for a recording (e.g. in Audacity) actually creates a real stereo signal on my machine.

Has anyone noticed a similar behaviour?

Thanks for your suggestions, cheers,

Philipp

Hardware: HP EliteBook 8540w, IDT audio codec

Software: Matlab R2009b, Windows XP SP3

[Daniel Shub]

Are you sure? Unless you have a very unusual mic, your mic is mono and I would expect either noise or an identical signal on the other channel.

[Philipp]

Actually that seems to be the case. My laptop only supports a mono input also on the mic jack and no additional stereo line in. The Audacity recording only created the illusion of a stereo signal. With audiorecorder the readings of both channels actually are identical.

Thanks, Philipp