Wednesday 23 February 2011

An Experiment in English Phonology

We normally think of English as having voiceless stops, /p t k/ and voiced stops, /b d g/. Voiceless stops have an aspirated allophone [p_h t_h k_h] that appears in certain places, particularly when the stop appears at the beginning of a syllable. Aspiration, in this model of English pronunciation, is a redundant secondary feature of voiceless stops.

However, on the Conlang Mailing List, And Rosta proposed an alternative model. His idea is that English actually has aspirated stops /p_h t_h k_h/ and unaspirated stops /b d g/. Voicing would be a redundant secondary feature of unaspirated stops - the [t] in "stop" would actually be a /d/ that's lost its voice. And put forward a number of interesting theoretical arguments for this, but I thought that it needed to be tested experimentally.

If the standard interpretation of English phonology is correct, English speakers should find voiced and voiceless stops easier to tell apart than aspirated and unaspirated stops. In And's interpretation, they should find aspirated and unaspirated stops easier to tell apart than voiced and voiceless.

Bengali distinguishes between plain (voiceless, unaspirated), apsirated, voiced and voiced aspirated (breathy voiced or murmured) stops. I asked a Bengali speaker to record a sample of 20 words which you can listen to here and transcribe them in CXS. I then asked three volunteers from the Conlang Mailing list, all of whom were monoglot English speakers, to listen to the recording, and trascribe their first impression of what they heard. Here are the results.

OriginalListener 1Listener 2Listener 3

For each stop and affricate in the sample, I then recorded which of the four categories it fell into, and how the volunteers identified it. The results are as follows.
Heard as
ActualPlainAspiratedVoicedVoiced aspiratedOther
Voiced aspirated32001

From this we can see that English speakers correctly identify plain stops as voiceless 70% of the time. They almost always identify voiceless stops as plain, whether or not they are aspirated. Aspirated voiceless stops are always identified as voiceless. Voiced stops are almost always correctly identified, and voiced aspirated stops, which are alien to English, are never correctly identified.

These results are more consistent with voicing being the primary feature than aspiration. Sorry, And.

Monday 21 February 2011

A Fantastical Device for Identifying languages

If I were to say to you,
hajimemashite. buriikurii piitaa desu. douzo yoroshiku
you probably wouldn't understand what I meant. However, you would know that I wasn't speaking English (it's Japanese, as a matter of fact). Were I to say, however
'Twas brillig, and the slithy toves
Did gyre and gimbal in the wabe.
All mimsy were the borogoves,
And the mome raths outgrabe.

you would be able to recognise what I said as English, even though it doesn't make sense. Each language has its own phonotactics, the rules determining how sounds can be combined to make words. Therefore, you can identify a language by its sound even if you can't understand it.

I've seen a lot of language identification software on the web, but it all works from written text. We conlangers, or course, like to game the system by putting in our conlangs and seeing what happens. I thought it would be fun to try building a system that could identify languages from speech. So, I've started off a project on Google code to try my ideas out. The idea is to use a stripped-down speech recognition engine to extract a stream of phonemes from audio, and then feed those phonemes into an AI system that has been trained to recognise the phonotactics of various languages.

Wednesday 16 February 2011

My "Native American" name

Last year, I did a project extracting semantic data from the BBC's archive catalogue. I presented the results to a senior colleague, who now wants me to present it to some academics who are involved in a collaborative project. The thing that seems to have stuck in his mind about my presentation is that I demonstrated my results with an old wildlife programme about a bird called a Red Tailed Hawk. He therefore described me in an email as
The bloke who can find a nesting Redtail Hawk in 1,000,000 hours of tape and film
. As a result, I was put on the agenda as "Hawkfinder".

I therefore seem to have acquired a Native American name. I'd be interested to hear how it would come out in various conlangs - particularly Native American inspired ones like Jeff Burke's Central Mountain Languages - so leave me a comment with your translation. In Khangaþyagon it would be


ketarg- slat- ont- rik
hawk find PrP man

Also, what would your "Native American name" be, and why?

Thursday 10 February 2011

Oh, It Makes Me Wonder

Gradus ad Parnassum, meaning Steps to Mount Parnassus (in Greek mythology, the home of the Muses), is a famous musical composition textbook from the 18th Century. It taught, in a series of step-by-step lessons, the rules of the musical technique known as counterpoint, where several different melodies are composed to be performed in harmony with each other. Of course, once the student had mastered the rules (it was very technical), they would hopefully be able to work out for themselves where they could get away with breaking them for artistic effect.

Led Zeppelin's most famous song is called Stairway to Heaven. You know the one - starts of gently with 12-string guitars, recorders, and references to Tolkien, and gradually becomes more Hard Rock as it progresses (You can listen to it in Pete's Progcast if you wait long enough for it to come round). The resemblence between the title and that of the Baroque music textbook may seem like a complete coincidence. However, there's a bit near the end that goes
And as we wind on down the road,
Our shadows taller than our souls,
There stands the lady we all know
Who shines white light and wants to show
How everything still turns to gold.
And if you listen very hard
The dream will come to you at last
Where all are one, and one is all,
To be a rock, and not to roll!

If you're singing Stairway to Heaven on a karaoke night, about halfway though this bit you realise that you're really going to need a drink after this. Each line of the passage goes to just about the same tune, but is pitched a little bit higher than the one before. In musical terms, that's called a canon. It's a technique that was frequently in the type of music that Gradus ad Parnassum teaches,

Tuesday 8 February 2011

What are the odds of a planet having a large moon?

As Dr. Maggie Alderin-Pocock pointed out in Do We Really Need The Moon?, our Moon is unusually large in comparison to its parent planet, and the large tidal forces it generates are thought to have been very important to the origin of life on Earth. She therefore suggested that when looking for life on other planets, we should concentrate out efforts on other planets that have large moons.

Our Moon, according to the best theories we have, was formed when another planet, the size of Mars, crashed into the early Earth. This, at first, sounds like a spectacularly unlikely event. It may sound quite discouraging if you were hoping to get in touch with aliens. However, models of the early solar system show that it was quite a violent, chaotic place, and space rocks crashing into each other is pretty much how the inner planets were formed. So, is there any way we can calculate the probability of a planet having a large moon like ours?

The best way is to make an empirical estimate, and it turns out to be a lot easier to do than you might have expected, and to have quite encouraging results. There are four rocky planets in the inner solar system. One has a large moon. So the odds of a rocky planet having a large moon, based on the available evidence, is 1/4. (± √3/8)

Wednesday 2 February 2011

Do We Really Need The Moon?

I used to be an astronomer (Ph.D from Leicester, studying Active Galactic Nuclei) so I quite enjoyed Do We Really Need The Moon? on BBC 2 last night. The programme explored the effects the Moon has on the Earth, and how those effects have been helpful to the development of life.

I also found the presenter really interesting. If you look at my profile photo, you'll see that I belong to the same demographic group as most people with physical sciences Ph.Ds. Dr Maggie Aderin-Pocock is in the intersection of two groups who are severly underrepresented in the physical sciences. On top of which, she mentioned that she is dyslexic, which is a condition that can limit a person's educational opportunities. Hopefully, people who had thought that they weren't the sort of people who could be a scientist will have seen the programme and realised that maybe they could.