What is a monotone voice?
A monotone voice is one which doesn’t vary much in pitch; the range of intonation is much flatter.
Andy Murray is an extreme example of this – he’s the most monotone man in our database. However, a lot of actors have this kind of voice too – Tom Hiddleston, Harrison Ford and Alan Rickman are all good examples.
How can you tell if you have a monotone voice?
Well, sorry to get to the sales pitch so early on, but there’s only really one way of telling, objectively, if you have a monotone voice. Vocular scans your voice recording to tell you how varied or monotone your voice is, as well as other stuff like your voice depth and how much vocal fry you speak with. You can see an example of the analysis below. Anything under 10Hz we classify as monotone and anything above 20Hz is fairly varied. 30Hz tends to be so varied you only see it in a few speakers like David Attenborough.
What causes a monotone voice?
Testosterone definitely seems to be one cause. Men tend to have more monotone voices than women, and this change kicks in during puberty – as the voice drops in pitch, it becomes flatter and less intonated too. Similarly, a study which pitted men against each other found that those with higher testosterone levels had more monotone voices, and these same men also had stronger arms and sounded more dominant than the other men.
This is something we see in Vocular’s database too. Not only did the 50 most monotone voices all belong to men, the Top 3 all belonged from former #1 tennis players: namely Andy Murray, Novak Djokovic and Roger Federer. So it fits the brief of a competitive personality almost too well…
As for other causes, it’s hard to say for sure but a flatter tone has been correlated with a couple of surprising things. The first is that men with monotone voices seemed to be healthier than other men. A study on immunity found that these men gave themselves better general health ratings, had higher future health expectations, and greater levels of a salivary antibody, sIgA, which has been linked lower rates of cancer and respiratory disease.
Another surprising connection was that men with monotone voices tended to have more sexual partners, even though these voices were rated as no more attractive than the more varying voices. More on this in the next question…
Are monotone voices attractive?
This one really depends who you are and where you are. If you’re a man in the English-speaking world, then being monotone doesn’t seem to make a difference to your vocal attractiveness. Studies don’t tend to find a correlation and you see this in the voices people claim to like – for every Alan Rickman or Tom Hiddleston there’s a Morgan Freeman or David Attenborough.
However, studies done in French, Chinese or Japanese all find a monotone voice to be unattractive in both sexes. This is probably a cultural thing stemming from the language – for example, Mandarin is a tonal language and relies on changes in pitch to give words their literal meaning, so a monotone voice sounds quite alien in China.
This also fits the general observation that familiar-sounding voices tend to sound more attractive. Even though everyone thinks they hate the sound of their own voice, they most likely don’t. If you take a recording of someone, mix it in with a bunch of voices all saying the same thing, then get that person to rate how attractive they find each voice, they generally give their own voice a high rating.
For women in the English-speaking world, annoyingly I could only find one study, but this found that, like with men, being monotone didn’t make a meaningful difference. You can see this in the table below (where F0-variance refers to how much intonation a voice has). In fact, none of the objective measures these researchers examined had a meaningful effect on how attractive women sounded. You can see this below, where asterisks indicate significant results.
Then why did a monotone voice predict sexual partners?
Well, there are basically two modes of sexual selection. Everybody knows the first, which is selection by the opposite sex (i.e. a particular trait evolves because the opposite sex finds it attractive). However, there is a kind of selection from the same sex too. Some traits emerge because they scare off love rivals. Beards are a classic example of this – they tend to make men look less attractive on average, however they also make men look more threatening, which makes it easier to stop other men from getting in your way. Basically, sexual selection is magnetic: it’s not just about attraction, it’s also about repulsion.
So why all the hate for monotone voices?
If a monotone voice really signifies health and doesn’t usually make voices less attractive, then why is it something people complain about, like nasality or vocal fry? Well, I think there’s a bit of a linguistic trick going on here. See, a monotone voice is not the same thing as a monotonous voice, there’s actually almost no correlation between these two things. You can see this in table below, where the r-value is -.02. That’s about as uncorrelated as it gets.
Thanks for this interesting post. Could you provide the reference of the research paper backing it up?
Sure, is there a particular point you want the reference to? About four or five papers went into this
Ok, great! I was mainly thinking about the ones focused on the link between monotone voices and attractiveness, but I guess it would be fantastic if you could share all your references on this topic!
Many thanks, and really looking forward to try your great app as well, but I have a sore throat right now and it seems that my voice is lower than usual, so I have to wait a bit before recording my baseline! 🙂
Sorry this has taken a while. I’ve been helping my father build a house outside of work so I haven’t had a whole lot of free time this week. Anyhow, the ‘dating game’ experiment is from a paper called:
“Voice Correlates of Mating Success in Men: Examining “Contests” Versus “Mate Choice” Modes of Sexual Selection” by Hodges-Simeon, Carolyn R., Steven JC Gaulin, and David A. Puts
If you search it in Google Scholar, you’ll be able to find a free copy there. There’s also a great book called Everybody Lies by Seth Stephens-Davidowitz, which is mainly about using search data to learn things about people and various communities, but he also mentions a study which shows that one of the best predictors of whether a guy would get a second date is how monotone his voice became during the date.
The points on vocal attractiveness come from a paper called “The attractive voice: What makes it so?” by Miron Zuckerman and Kunitate Miyake. I’m not sure how I got it, because I can’t find a free version online anymore, but if you can get one, the appendices were the most interesting part for me – they basically show correlations between a load of different acoustic and subjective features, like pitch variation and ‘deepness’ or ‘monotonousness’. Hope that helps and let me know if there’s anything else you want to know!
Girl here. I hate monotonousness voices. I have pentrating voices. I love spearling lively voices on men and women.
I cannot even listen to them, and I tend to talk all over them. They are the most annoying voices I have ever heard. That gravelly zero intonation flat voice that your uni lecturer had that either sent me to sleep, or made me visiably angry when I had to listen. I think Belgian men are the worst, because they all sound the same, with monotou=nous voice ( Sounds like they’re life is so miserable). So no, men with monotonousness will make me run a mile. How can I have good conversation with someone who sounds like they’re going to die?
Hi Sophie, yes, as I say in the blog post, a monotone voice is a very different thing to a monotonous one. Monotone voices are actually no more likely to be described as monotonous than voices which are varied in pitch.
You can kinda see this in the list above as well. Tom Hiddleston has a famously nice voice – but his is the 5th most monotone in our database. If that were such a problem, we’d expect him to be way down at the bottom instead.
Hi, Monotone voices are as bad as monotonous voices. They have the same effect on me.
So you don’t like any of the voices on the list of 12 above? Which men’s voices do you particularly like?
I am a women with a monotone voice.Its no fun.When your excited or anxious it seems like your yelling and are mad when your not.Also my voice has got me arrested because I sound confrontational.
I’ve also noticed competiveness from men.
I’ve been called sir when they can’t see me.I always am mistaken for a miserable shriek in hiding.I think my voice is a weapon of mass distraction.But men love it!
My mistake. i had confused monotone with monotonous.
My apologies to all.
I am fine with a monotone voice.
I just watched an Emily Blunt interview. She has a very similar accent to mine but my voice is less monotone than hers. I did not know this was what monotone described. I hust thought this was more more accent. Mine is just as RP as hers!
Apologies to anybody I offended.
You’re so dumb Sophie good God…you were so rude about how boring monotone voices are, and then you see a woman say she has one, and you changed your mind. Well I’d rather date someone with a monotone voice than your cunt personality. You are so self righteous that I’m shocked if I found out that any men are interested in you at all.
Ha ha ha that was some hilarious observation there on Sophie!
Cahz mate, you’re doing a lot of talking shit for someone that bullies people in the comments of research papers. Go outside buddy, touch some grass x
Wow, you’re a bitch and annoying as hell, I’d wager. Youre one of those birds with a high pitched sharp cackling and fakey brassiness, off-Key and jarring. I bet when you speak everyone else gives sideeye to one another, because youre so fucking clueless and loud and obnoxious. You make everyone wish for death, maybe thats why they sound like that to you.
My voice as I am a lady with a monotonous voice.To some it’s like fingernails on a chalkboard.
It has actually got me arrested more than once they tend to rule it aggressive.
I’ve even been called sir every time I’m on a phone call.I am constantly judged a miserable awful Shrek.But mostly misunderstood!
Men always want to compete with anything I do.
Men are always turned on by my voice.
In conclusion I think my voice is a weapon of mass destruction.
Same here. Men LOVE my voice. They also react very badly to it if they are authoritarians with weak egos, like cops or professors or doctors. Then, Im “mouthy”, when Im not. I am just straightforward and firm, traits they see as rivals to their own, and they are losing the battle.
I do wish I had a bit more melody to my voice however. When I was young, I could sing. Now i cant hit any mid-high notes and even the low ones are off key, it cracks and vanishes altogether.
There is a difference between expressing an opinion and acting rudely by calling somebody stupid. I am the former. Which one are you?
Additionally I opened my post with “My mistake… My apologies to all”.
You should offer to apologise.