Take the words ‘irregular’ and ‘erectile’; the ‘r’ sound in the first one is clearly different from the second (at least to my ear). In ‘irregular’ we have a double ‘r’ sound: ‘ir-reg’, while in 'erectile' we have a single 'r' sound ‘i-rec’. Yet dictionaries show identical phonetic transcription for both; in Oxford for example: /ɪˈrɛɡjʊlə/ and /ɪˈrɛktʌɪl/, and in Cambridge: /ɪˈreɡ.jə.lər/ and /ɪˈrek.taɪl/.
Contrast with a pair like ‘dissatisfaction’ vs ‘disambiguate’. In this case, we have ‘dis-sa’ and 'di-sa’ sounds, and dictionaries distinguish between the two cases by transcribing the first with a double ‘s’; again in Oxford: /dɪssatɪsˈfakʃn/ and /dɪsamˈbɪɡjʊeɪt/.
Pronounce to yourself 'erectile' by doubling the 'r': /ɪrˈrɛktʌɪl/ (ɪr-rɛk), the way 'irregular' is pronounced. Surely it's different from /ɪˈrɛktʌɪl/ (ɪ-rɛk). Also pronounce to yourself 'irregular' by dropping the double 'r': /ɪˈrɛɡjʊlə/ (ɪ-rɛɡ) , the way 'erectile' is pronounced. Surely it's different from /ɪrˈrɛɡjʊlə/ (ɪr-rɛɡ).
My question is very specific: are the two sounds in the first segments of the words pronounced exatly the same or not? And if they're not the same, why isn't this reflected in the phonetic transcription.
When I say a double 'r' sound, I'm not referring to repeated flapping or vibration of the tip of the tongue against the hard palate in heavy rhotic 'r' sounds, as is the case in Arabic. Sure, an 'r' sound with a repeat flapping of the tongue would most likely indicate a non-native pronunciation.
The double 'r' sound I'm talking about can occur with a non-rhotic 'r' too, where the tongue is pressing against the air flow between it and the hard palate for a longer time than it would take to pronounce a single 'r' sound. What I'm suggesting is that the 'r' sound in 'irregular' takes longer than the 'r' sound in 'erectile', whether or not we're using a non-rhotic 'r' pronunciation; hence this should be reflected in phonetic transcription.
1. American pronunciation:
My original position was based on the British accent. After listening carefully to the american pronunciations in a bunch of dictionaries, I accept that the pronunciations of both words seem to similar. To my ear, Americans seem to be pronouncing them both with a double 'r', which is the same way tha 'irregular' is pronounced. So the American pronunciation is 'ir-rec-til', rather than 'i-rec-til'. Of course the last syllable is not a diphthong like in the British pronunciation.
2. British pronunciation:
The only dictionary with full sentence pronunciation I could find was Longman. While the entry for 'irregular' has many sample sentence, 'erectile' is not listed, so I used samples from 'erected' and 'erection'.
I provide now direct links to the sample sentence pronunciation, where the reader can listen and compare for themselves:
Next I provide three screen shots of segments from the audio patterns for either words in some of the sentences above as shown in Audacity(audio software). I will comment on these patterns below:
- 'irregular' in example 1 above (ir-reg ends between 1.5 and 1.6 time marker):
- 'irregular' in example 2 above (ir-reg ends just before 1.20 time marker):
- 'erected' in example 4 above (i-rec ends around the 1.70 time marker):
What we can observe in these patterns, is that the segments till the end of the first consonant after 'r' ('i-rec' or 'ir-reg') generally form two humps. We can see clearly that for the 'ir-reg' cases (patterns 1 and 2), the first hump (representing the 'r' sound) is more extended than the second hump, and this difference is more pronounced in pattern 2. While in the 'i-rec' case (pattern 3) we can see that the two humps are of equal length, indicating a shorter 'r' sound.
Of course this is not an extensive analysis, but at least it's a case in point.