'Kiaranda saravustu,' he cried. He had no idea what the words meant, or where they came from.
'A verbal ejaculation is the only way I can think of to describe it,' he says. 'And I thought - what on earth was that?'
Mr Coates took his unexpected linguistic epiphany in his Christian stride. A few weeks later, a Pentecostalist friend he was praying with laid hands on him, and his tongue was divinely loosened again, 'in a flow of love and worship and adoration'. Immediately the connection between his bicycle experience and some verses from the Acts of the Apostles became apparent:
And suddenly there came a sound from Heaven as of the rushing of a mighty wind, and it filled the house where they were sitting . . . and they began to speak in other tongues as the spirit of God gave them utterance.
A further reference, in Corinthians, to 'the tongues of men and of angels' also began to make sense. This was the language of Heaven - the antidote to the tongues of Babel.
Mr Coates was a member of the Plymouth Brethren at the time, but the Brothers did not take kindly to his tongues. They asked him, he says, 'in the nicest possible way', to leave. Other churches might have rejected him too. Tongues are a political issue in Christianity: some of the Establishment regard the phenomenon as a walk on the wild side, a fringe stunt by the 'happy clappies'.
But as Mr Coates points out, it is their churches which are emptying, not his. He is now a minister in the Charismatic evangelical movement, named after 'charismata', the Biblical 'gifts of the spirit', which include healing, prophecy and speaking in tongues. There are over half a million evangelicals in Britain, half of whom are reckoned to speak in tongues.
Phoneticists have a more prosaic word for the 'language of angels': the Latin term 'glossalalia', which literally means 'babbling in tongues'. Linguistically, it is related to the 'jargoning' of babies and to jazz 'scat', the shabba- dabba-doo, gabba-gobba sounds made when the tongue is allowed to run on autopilot. While many people are too inhibited to attempt it, the sounds are simply on the far range of a scale of meaninglessness that begins with utterances such as sighs, groans and cheers - and presumably also the 'primal scream' familiar to the New Age movement, which charismatic evangelism regards as its pagan enemy.
'God's own language' is a primitive one, according to Professor John Wells, Professor of Phonetics and Linguistics at University College, London. The sounds are too repetitive, the syllable patterns too restricted and the consonant clusters too few and far between to warrant any attempt at translation. Glossalalia is a small, intriguing footnote in the history of language.
'It's a vocalisation which is not within linguistic control,' he says, 'though it tends to conform to the phonetic patterns of the people speaking it.' He believes the phenomenon has a psychological explanation: 'It seems very important in religious experience to somehow allow one's inside to get free of controls and inhibitions, including the linguistic controls which we normally apply.'
Meanwhile, in a Pentecostal church in north London on a weekday evening, Pastor Joseph Nartoy leads the congregation in a rousing hymn. Halfway through, the music collapses, giving way to a few chords on the electronic keyboard, and the 50 or so voices erupt into babble. It's an eerie, mellifluous cacophany, half-sung, half-whispered. The worshippers stand with their eyes closed, swaying slightly. One woman appears to be in tears, another punctuates her flow of gobbledygook with the occasional Hallelujah. The rush of tongues continues unabated for about five minutes and slowly fades as the keyboard slips back into the hymn's melody. Normal service is resumed.
Afterwards, the pastor is happy to give an example of the kind of thing he says when speaking in tongues: 'Kooramasandalamakoostibari,' he says, 'Indurikishibabala.' The sounds are not so much words as a seamless burble of consonants and vowels: 'annallyakasabundrimikissi'. Yet the intonation gives the impression that there is meaning behind it.
The pastor says his own spiritual language developed in much the same way as a child's, but faster. Mr Coates also reckons that the more he spoke in tongues, the more his vocabulary expanded, and he describes the language he speaks as sounding 'rather Italianate'. The feeling, the pastor explains, is of pure joy 'as the spirit of God gives utterance'.
Both men say they haven't a clue what the spirit is uttering. It is like being a receiver for foreign radio signals. Worshippers do sometimes have a stab at the gist of what is uttered, and speakers of tongues are fond of quoting St Paul: 'You who speak in tongues pray that you may also interpret.' But in an odd way, the very untranslatability of the 'language' may be the point: the meaninglessness is the message. It has a post-modern ring to it. God moves in a mysterious way, and speaks in one too. But it does seems unfair. You spend hours praying for Him to speak, and when He does, it's divine gibberish.
Prof Wells takes a more down-to- earth view. Anyone, he reckons, can invent a nonsense language. He is even willing to have a go himself: 'Labadiccadowdebalowdicabowji,' he says.
Which is food for thought.
Liz Jensen is the producer of 'Word of Mouth' on Radio 4 which features an item on speaking in tongues this Wednesday at 6.30pm.Reuse content