How can you voice deepen after a night out?

[marmaduke]

My friend Keith says that his voice is often far deeper, and he can reach lower tones in the morning after having gone out for a long time (including drinking). Why? How?

[Morrisonker]

because he's been smoking more than usual or has been in a smokey bar or club?  That can really affect your voice.

[morg_monster]

This question was asked and answered in the Last Word sectino of New Scientist magazine a few years ago. unfortunately I can't remember the answer and can't see it online without a subscription.

However I found the following on http://www.abc.net.au/science/k2/moments/s502634.htm

which basically says that in the mornings in general and in particular after drinking alcohol or smoking your vocal cords are more 'relaxed', hence a bit thicker and so your voice is deeper.

As a squeaky girl I love my husky post-booze voice...!

[Scarlett]

As a singing teacher, I know that I can sing far far lower first thing in the morning, and far higher later in the day! It has to be because your vocal chords have relaxed in the night, I would say.