Why does my voice get deeper when I have a cold?

[sub](Note: I did a search for this question going back over the last year, so I don’t think this has been asked, at least not recently. Words like “cold” tend to generate a lot of responses, though, so I may well have missed something. In that case, I apologize in advance.)
[/sub]I’m just getting over a cold. Nothing too dramatic, just a stuffy head, occasional touch of sore throat, infrequent cough, runny nose, and, yes, the telltale shift in vocal pitch down toward baritone gravel. It’s almost done now, and my voice is returning to normal, but I have to wonder:

Why does this happen? Does the cold virus affect the vocal cords – making them swell, stretch, or something – which makes my voice deeper? Or is it a side effect, say, the throat responding to draining mucus? Does this happen to everybody, a majority, a few, or what? I also notice that drinking hot fluids, like tea, temporarily increases the effect, apparently by clearing the mucus and allowing the vocal passages to really resonate cleanly, before the sicky-juice stuff clogs me up again.

What exactly is going on here? And perhaps more importantly: How come I can’t do this voice on demand when I’m not sick?

It must be related to the physical properties of the vocal folds. In order to change the natural resonant frequency of a guitar string, you make it either longer or thicker. I would guess that the vocal folds are getting inflamed and therefore thicker. The raspy quality may come from mucus/phlegm coating the folds and becoming dislodged as the folds vibrate.

Now we need a doc to come by and tell us if the vocal folds do in fact become inflamed during a cold/flu.

IANA doctor, but IAA choir member, and I’m here to tell you that yes, when you get a cold your voice goes all to Heck, and it’s because your whole nose/throat/larynx/pharynx assembly is lined with mucous membranes, and we all know what mucous membranes do when they’re full of cold virus, don’t we? That’s right–they swell up and drip, in an attempt to repel the alien viral invaders. So your vocal folds do, too, and you might as well resign yourself to singing alto for the duration. A very low alto.

http://www.fc.peachnet.edu/floyd/academics/biology/lc/261/261urt.htm

So not only are the vocal folds themselves swollen (“swollen = no sound”), they’re also full of extra mucus (“excess mucus = no sound”). And if it’s really bad, it’s called “laryngitis”.

The reason hot liquids help is two-fold. The heat itself helps loosen things up, and the extra liquid helps make the mucus looser, “runnier”. Think “chicken soup” for your voicebox. The same way hot soup makes your nose run, hot tea makes your ailing voice box loosen up.

The hot tea doesn’t really directly help your voice box, because it goes past it, on its way down the esophagus. Your epiglottis closes off your windpipe when you swallow the tea. If it did go directly through your voice box, you’d choke to death (“down the wrong pipe”).

Tip from singers: Clearing your throat repeatedly sometimes just makes the “mucus thing” worse, because it irritates the vocal folds when you do it. It’s an explosive thing (“harumph harumph harUMPH!!”) and the vocal folds don’t appreciate it much, and respond by putting out even more mucus to cope with the irritation.

The reason you can’t make this sound on demand when you don’t have a cold is because it’s due to the vocal folds being (a) swollen, and (b) coated with excess mucus, and you don’t have any way to make your vocal folds swell up or to be coated with mucus.

However, if you really enjoy the sensation, you can recreate it quite easily by going somewhere private and screaming at the top of your lungs for about 15 minutes. That should give you a very satisfactory hoarseness.

Or you can go out in the garage and sing along to your Guns N Roses karaoke. :smiley: “Annnhhh–annnnhh–annnhhhh- sweet child o mine…”

Huh. That’s interesting. I was curious about that myself–whenever I get sick, my voice has a tendency to go down below Vader level–sometimes so deep I have difficulty understanding myself.

Also don’t forget the social-reinforcing effect–since we all know what sick people sound like, we also have a subconscious tendency to imitate them we ourselves are sick…

Thanks for the info so far, and thanks, DDG, for favoring me with your legendary Googling skills.

I’d like a bit of clarification, though. I figured the voice-pitch thing was due to swelling or something similar, but what I couldn’t figure out was why swelling would make the voice deeper instead of higher. Seems to me that if the vocal cords – um, okay, folds – swell up, they’d get tighter. Tightening a guitar string makes the pitch go up. What’s different in my throat?

Further, the tissues surrounding the vocal folds generally swell up also, constricting the air passage and, again (it seems to me), making the pitch rise. Obviously, something else must be going on here. Do the folds swell long-wise more than cross-wise, essentially lengthening them and making them looser than usual, and thus accounting for the deeper voice? Or is there something else going on?

Cervaise, I can see why the lowering of pitch is a bit counter-intuitive, but it just works that way in the voice. Attrayant’s guitar string analogy (i.e. lower = fatter) is a good one.

Pitch variation in the voice comes from a number of factors (length, relative tautness, thickness, the degree and firmness of glottal closure, etc.), but generally speaking the lowest “register” (think functional coordination – to make different kinds of sounds, the vocal folds come together in different ways and to different degrees) of anyone’s voice occurs when their folds are at their thickest. In contrast, the highest register of the voice is accompanied by the much thinner vibrating edge on each of the folds.

So, when the muscles and mucous membranes swell due to irritation, congestion, injury, or illness, the resulting fatter vocal folds result in an artificially low register becoming available to you. It’s like having a temporary vocal transplant.

Yeah, like, what he said. :smiley:

When you sing high, you’re actually making your vocal folds thinner. Thin = high pitch. When you sing low, you’re actually making your vocal folds thicker. Thick = low pitch.

So, when you have a cold and your vocal folds get real swollen and thick and coated with mucus, you’re “singin’ down cellar”. :smiley: