Tuesday 14 June 2011

fortis and lenis

Victor Martínez, who is originally from Mexico but now lives in the United States, wrote
I am learning phonetics right now […]. I have a question for you: what is the phonetic difference between a voiceless [b̥] and an unaspirated [p] (as in Spanish pájaro)? I think that there is no phonetic difference between the two. If there is no difference between the two, then why do people ever use the symbol [b̥], when [p] is less complicated and means the same thing? Is this only for phonological reasons? I have looked through many linguistics books and I have not found a clear answer to this seemingly simple question.
I replied
Voiceless [b̥] is "lenis", whereas [p] is "fortis". Lenis plosives have less intraoral pressure than fortis ones. See Wikipedia, or see my Longman Pronunciation Dictionary (3rd ed.) p. 881.

The difference is easily noticed in the English pair "touched" vs. "judged" (said in isolation). The final consonants are pronounced without vocal fold vibration in both cases. But the fricative component of the affricate in "touched" is much noisier (more turbulent) than that of the affricate in "judged".
I might have added that this is presumably because in devoiced lenis obstruents the vocal folds adopt the ‘whisper’ position, i.e. are narrowed, unlike the wide open position that they adopt for fortis obstruents. This reduces the flow of air and therefore reduces the amount of turbulence.

Try it out. If you’re a NS or have a NS-like command of English, you should have no difficulty in hearing and feeling the difference between the voiceless fortis [tʃt] of touched and the devoiced lenis [d̥ʒ̥d̥] of judged. (Sorry I don’t have any instrumental evidence to hand with which to back this up. I assume experimentalists could easily furnish some.)

In English the fortis/lenis contrast is usually reinforced by other factors. Syllable-initially, before a strong vowel at least, fortis plosives have aspiration, while lenis plosives don’t. Even with fricatives there is a clear difference in VOT. Syllable-finally, fortis obstruents trigger pre-fortis clipping (duration reduction) in the preceding vowel (and sonorant, if there is one), and again lenis ones don’t. Between voiced sounds such as vowels, fortis obstruents have no voicing (always excepting AmE-style /t/), while lenis ones generally have voicing.

Since the presence vs. absence of aspiration is perceptually and instrumentally more salient than force of articulation itself, Spanish-style unaspirated initial p can easily be confused with English initial b in a word in isolation.

In some languages (Icelandic is a good example) all plosives are voiceless, but there is a clear contrast of fortis vs. lenis. See here. In my blog I last touched on the topic of fortis and lenis over four years ago, on 4 April 2007. That was before readers could leave comments. Now you can.


  1. In Danish all plosives are lenis, so /p/ is [b̥h].

  2. Many years ago when one of our sons was ten years old and we lived in Switzerland (we are American), he had a friend named Tomas, and when he told us about him he used the lenis "t". I knew about the distinction between fortis and lenis, but when I said it I had to stop and shall we say gear up to saying the t without a puff of air after it. He, being ten, said it right in the middle of conversation without even pausing (or, I assume, without even knowing he was doing it).

    I was jealous.

    Charles Wells

  3. My two-year-old (English-speaking) daughter is being taught the Spanish numerals at her preschool. Her "tres" is an exact homophone of her English word "dress".

  4. I was wondering the other day what the perceptual cues would be for distinguishing fortis from lenis unaspirated voiceless plosives -- impressionistically, it seemed like fortis plosives created a perceptible burst on release, whereas neither I nor my companion at the time perceived any such burst on the release on a lenis plosive. Does this impression have any basis in reality as far as you know?

  5. Charles Wells: Since you mention the puff of air, it sounds like you might be talking about the aspirated/unaspirated distinction instead.

    What language was 'Tomas' speaking? 'Tomas' isn't a particularly German, French, or Italian name ('Thomas' is the usual spelling in German and French), but maybe this was a Czech name or something.

    German plosives are usually aspirated as in English (pronounced with an audible puff of air), but in Switzerland they are generally unaspirated. French and Italian plosives are also unaspirated. So in all major Swiss languages the 't' of a 'Tomas' would be unaspirated. But it would also be definitely fortis.

  6. Wait, wait, wait... since when are final obstruents completely devoiced in English? I just checked, and my judged pretty clearly retains a voiced [dʒd]. At most, perhaps the voicing trails off, leaving something like [dʒd̥]

  7. dirck,
    If you're sure of that, it's worth mentioning. I was sure I usually had [dʒ̊d̥], but I would admit to pronouncing the whole thing as [d̥ʒ̊ʌdʒ̊d̥]! So I didn't think it worth mentioning.

  8. I also see from that diagram that Spanish /s/ is less loud than English /s/; is that because the former has no /z/ to contrast with?

  9. Army1987, depending on dialect and context, that Spanish /s/ might be well on its way to [h] or even a glottal stop.


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