Helium- Big ol’ duh as most everyone has done this(keep yo safety warnings out of here!)
Nitrous- Ok even if aren’t a druggie you have to try this, it is crazy! Breathe in some nitrous and talk as you exhale :eek: HOLY CRAP! It makes you sound like a Goauld from Stargate. Seriously this enriched my life, I can die knowing what it sounds like to talk to nitrous in your windpipe.
Sweetart under your tongue, for whatever reason my voice is not only deeper but has a southern drawl talking with one of these candies sublingual.
Are we talking permanent or temporarily here? I can think of many a permanent ones…cut the nerves connected to vocal folds to make your voice more whispery, traumatic event can trigger stuttering, various lesions (cerebellum, basal ganglia, lower nervous system, etc.) can cause hyperkinetic or hypokinetic dysarthria. Imbalance of dopamine to aceytalcholine can create a croaky hoarseness, a stroke to a certain spot of the brain can cause Broca’s aphasia which produces effortful speech…the list goes on and on, really.
The one temporary one I can think of is Botox. Inject that stuff directly into your vocal chords and it’ll give you a breathier voice for a few months to come.
Well, as someone who performs in theater and in audio dramas, there are ways to change the sound of your voice without resorting to artificial means.
With a bit of training and/or practice, you can learn to speak from the diaphragm, which, depending on your own particular pipes, can make quite a difference. My voice teacher in college wanted me to start speaking with my diaphragm voice all the time, but I couldn’t pull it off socially – going from Kermit the Frog to a Barry White wannabe in no time flat caused just a few too many guffaws. Even without the constant exercise such an alteration would have provided, my singing voice went from a thin, high nasal to a resonant, booming bass-baritone.
Even without training, if you have an ear for accents it can alter significantly the way others hear you, even if the sound itself isn’t much different. The most effective method (I find) is to find a recording of someone speaking in a particular accent, practice speaking along with them, and pay particular attention to the changes in the vowels and those consonants that are highly distinctive. Languages and dialects may have peculiarities in the way one arranges the vocal tract that are passed on when native speakers of x or y learn to speak English. The best example I can give is Hindi. Speakers of Hindi curl their tongues back slightly when pronouncing their own language, and it is this that gives their English that clipped sound.
Similarly, but not necessarily related to accent, vary the shape or arrangement of your vocal tract and speak normally, just to hear the difference. For example, speak with your lower lip pressed against the front of your teeth. Or push the point of articulation into the back of the throat. Play with your voice. Record and listen to your results, because others may perceive a more dramatic difference in the sound than you can perceive yourself.