L-allophones

The usability of /l/-allophones as wb markers arises from the fact that their formant tran-sitions and frequency spectra depend on the surrounding phonemes. A palatalised /l/, for instance, that is exchanged by the /l/ stemming from the contextdie Pappe liegt/the cardboard lies might render the sound of the word unnatural.

5Possible variants with [+ fortis] stops had also been meaningful: pill, till, kill.

2.3.1. Production

Generally, the German lateral /l/ is a voiced coronal (Wiese, 2000). The sound is formed when the blade or the tip of the tongue touches the alveolar ridge, while the sides have no contact with the palate so that the airstream can escape through the two gaps (Hall, 2003, p. 56). Since there is no clear phonological rule for /l/-allophone generation in German, the variants of /l/ rather reflect fine phonetic detail. However, for the sake of readability, we will continue to use the term allophone.

Allophonic variations of /l/ in German are brought on by the neighbourhood of the liquid. During the articulation of the lateral, tongue position, as well as the front-back movement of the tongue’s body and the opening angle of the mouth adjust to the surrounding phonemes. It is also possible that the lateral influences the place of articulation of the preceding phoneme. This is for instance the case when /l/ follows a stop (e.g. Klippe/ cliff). What we see is a coarticulation process⁶, which usually leads to a palatalised stop which is no longer aspirated (Kohler, 1995).

While German has no clear allophonic rules for /l/, other languages have. In English, for instance, the phoneme /l/ appears in two allophonic variants - as a word-initial light form, e.g. lime, or as a dark variant in word-final position, e.g. call (Church, 1987). They do not contrast, because they cannot appear in the same context: light /l/ never appears word-finally, and the dark form never appears word-initially (Reetz and Jongman, 2009;

Hall, 2000).

Apart from the allophonic rule for /l/, the English lateral may also be erased or vocalised.

Some Commonwealth English variants display position-induced /l/-deletion. Speakers of Australian English, for instance, do not utter the lateral if it follows a low or back vowel. The pre-lateral vowel is lengthened (Proctor, 2011). Examples are:

calf → [k5:f]

almond →["5:m@nd]

(Examples taken from: Proctor, 2011)

Laterals in post-vocalic position are also prone to assimilation processes in some dialects of Northern England. Here, laterals in the mentioned location will be vocalised to a mid-back vowel: milk → [mi7k], [miUk] (Hardcastle and Barry, 1989).

6The phenomenon of coarticulation is resumed in section 3.2.3

2.3.2. Perception

Let us have a closer look at the example mentioned in the introduction to this section.

The wordPappel/poplar and the phonemically identical sequence taken out of the utter-ancedie Pappe liegt/the cardboard lies should be discriminable by listeners, because the final /l/ sounds natural in the first and unnatural in the second example.⁷ The reason, why the final /l/ in Pappe l[iegt] sounds “wrong” is that tongue and lip positions have already adjusted to the following vowel /i/.

The perception of targets with /l/ is sometimes difficult, especially if the lateral is in word-final position. There is a likelihood of confusion with rhotics. Frick (2003) demon-strated that in a gating experiment with German listeners. Frick’s participants heard sentences which unfolded phoneme by phoneme. Consequently, the acoustic stimulus expanded gradually. After each new phoneme that was added to the sound chain, test persons should write down the word/words/sentence they thought is developing. Some of the target words contained the lateral at a wb. Word-finally, the lateral was sometimes perceived as a rhotic if both resulting strings were meaningful and context was yet in-sufficient (e.g. vier/four instead ofviel/much). In sentence-initial position, /l/ was well recognised. This might be attributed to the phenomenon of phrase-initial strengthening (Nakatani, 1978). In this process the phrase-initial segment is lengthened. The longer duration of /l/ might have lead to a better distinguishability of the lateral.

The misperception of laterals as rhotics and vice versa is also known from other languages with two phonemic liquids such as Greek (M¨uller, 2010). Interestingly, the confusion dis-appears when test persons have to listen for /l/ and /r/ in nonsense sequences. Koo and Cole (2006) experimented with liquids and rhotics in non-meaningful strings and demon-strated that adults were able to learn phonotactic dependencies of a fictional language.

Among the phonotactic dependencies were liquid assimilation and dissimilation. Test persons first underwent a study phase in which they heard and repeated nonsense words that initiated the phonotactic constraint of liquid assimilation, e.g. salile- (C[onsonant]2 and C3 are identical liquids) or liquid dissimilation, e.g. salire (C2 and C3 are different liquids). After the training phase, they played targets to the listeners and asked them to distinguish legal from illegal words which the test persons mastered.

While two two studies are not directly comparable, the question remains why listen-ers performed better with non-meaningful than with meaningful speech. The answer is

7A direct comparison also demands schwa-deletion inPappe l[...].

probably rooted in the complexity of a natural language. When processing meaningful sequences, the auditory input is constantly compared to the entries in the mental lex-icon. Word candidates are activated according to the incoming phonetic/phonological information. The fictional language processed by the listeners of Koo and Cole (2006), however, followed some simple rules. Only a few words had to be stored in the mental lexicon. Hence, participants could concentrate on the task of word legitimacy judgement.

There was not a lot more of other information to process.

In this section, we have discussed the production and perception of /l/-allophones and how they might signal a wb. The following section summarises the functionality of silent intervals as wb markers in connected speech. Some linguists use other terms like “speech pause” or “silence” which are retained in the discussion of their research.