4.4.1. Reduction of downdrift

Downdrift is best observed in sequences of identical tones such as all-low sentences or all-high sentences. Downdrift in Ikaan has not been investigated in detail. All-high utterances consisting of more than one word rarely occur in Ikaan and are not included in this dataset. An all-low utterance exists in this dataset in utterance 3 ɔ̀jã̀nà ɔ̀bɛ̀ɡɛ̀ [ɔ̀jã̀nɔ̀bɛ̀ɡɛ̀] ‘s/he bought plantain.’

The graphs in Figure 7 plot pitch trajectories for each speaker for the low tones in ɔ̀jã̀nà ɔ̀bɛ̀ɡɛ̀ ‘s/he bought plantain’ as a statement and as a question. For most speakers, the first four tones are fairly level and the final low tone shows a downward drop.

Figure 7

Downdrift in ɔ̀jànɔ̀bɛ̀ɡɛ̀ ‘s/he bought plantain’ as statement (left) and question (right).

Table 3 and Table 4 list the pitch values for each low tone for each speaker. For the final low tone, the pitch is given in semitones for the beginning of the vowel-bearing tone (L_5(b)) and at the end of the vowel (L_5(e)). For each speaker, the pitch difference between the first and the last low tone is given, for both the beginning and the end of the vowel that bears the last low tone. Finally, the pitch difference between the first and the last low tone is given in semitones and as a percentage, averaged across all speakers.

Comparing the pitch of the first tone and the beginning of the last tone, in statements there seems to be a slight tendency towards downdrift for some speakers, while other speakers show less downdrift, and one speaker shows a very steady pitch with a raise at the beginning of the last vowel. In questions, there is a tendency to a steadier pitch (cf. Figure 7) with less downdrift, but again there is variation among the speakers, with some speakers showing more of a downward drift, others less, and one speaker showing an upward tendency until the beginning of the last vowel.

Overall, it seems that there may be some downdrift in statements and that this may be somewhat suspended in questions. However, compared to Connell’s (2001) reports on Hausa, using data from Lindau (1986), the Ikaan data shows less slope. Further research needs to be done to establish the extent to which there is downdrift in Ikaan and whether it is suspended in questions.

4.4.2. Raising of last H(s)

The raising of high tones was tested on utterance 15 in (16) and utterance 16 in (17). Utterance 14, which also contains more than one high tone, was excluded because it includes an object introduced by the locative marker b- ‘LOC.’ This marker seems to co-occur with register lowering in this context, which itself would mask any raising of the high tone.

Both statements end in consonants and receive an epenthetic vowel in the question (for more information on epenthetic vowel insertion, see section 4.6.). Therefore both utterances have an additional tone in the question.

Figure 8 plots the pitches of all high tones in semitones for all speakers. The trajectories suggest an upward movement for all speakers in utterance 15. In utterance 16, there is more variation between the speakers.

Figure 8

High tone trajectories in utterance 15 (top) and utterance 16 (bottom), with statements (left) and questions (right).

Table 5 shows pitch differences in semitones between the first and last high tones for all speakers and averages across all speakers.

In both statements and questions, the final high tone is usually higher than the first high tone in the utterance. However, this difference is wider in the question in utterance 15 and narrower in the question in utterance 16 compared to their counterpart statements, so that from the little data available here, no pattern emerges.

5.1.1. Prosodic markers fail to apply, vary, are decontextualized, or are jumped by hearers

The first language-internal issue with the use of the prosodic markers is that the prosodic question markers used by Ikaan speakers often rely on prosodic processes which require certain prosodic contexts in order to apply. These contexts, however, are sometimes just not given by the prosodic structure of the utterance and therefore the process cannot apply.

For example, without any high tones present, there is no pitch difference between low and high tones. If, in a larger data set, the wider pitch register proved to be a statistically significant marker in its own right, speakers would still not be able to use it to mark questions in all-low utterances as shown in (22).

Similarly, final lowering cannot distinguish questions from statements in utterances ending in high tones, as shown in (23), because high tones are not affected by final lowering.

In utterances ending in consonants, phonation mode changes and final lengthening are not applied. The final consonant in the statements does not show creaky phonation, even in the preceding vowel, as shown in (24) and Figure 19. Additionally, the durations of final consonants do not contrast with a longer vowel in the question counterpart.

Figure 19

Modal voice in the statement ɔ̌ːwʊ̀hjã́òjíd ‘S/he drank palm wine.’

A second issue in the use of the prosodic markers is that speakers of Ikaan noticeably vary in their use of some prosodic markers. Some of this variation applies to particular utterances or phonological contexts; other variation shows differences between speakers in the same context.

In the utterance ɔ̀há ‘s/he fell,’ all speakers use breathy phonation instead of creaky phonation in statements, as shown in Table 8. Why speakers use this breathy phonation is not clear yet, though the verb ha ‘see’ shows slightly different segmental behaviour as well, such as not undergoing vowel deletion or vowel assimilation across word boundaries, as other vowel-final verbs would do.

Nasal vowels do not take part in the creaky vs. breathy distinction as much as oral vowels. In some cases statements are not marked with changes in phonation mode. In others cases, questions are left unmarked. In yet other cases, both statements and questions only show modal voice, as in (25) and the waveform and spectrogram in Figure 20, both of which show modal voicing throughout.

Figure 20

Waveform and spectrogram for òʃéʃèdũ̀ ‘s/he stood up’ as statement (left) and question (right).

Across all utterances, Ikaan speakers use creaky phonation in 60% of all statements and breathy phonation in 89.5% of all questions (cf. Table 6 above). Modal phonation plays a minor role, with 13.3% of statements and 7.9% of questions realized with modal voice. This is different for final nasal vowels, as shown in Table 9, which gives the number of instances and percentage of occurrence of each phonation mode in statements and questions ending in nasal vowels. Whereas all phonation modes are attested in both contexts (with the exception of creaky voice in questions), there is a noticeably higher proportion of modal voice realizations in nasal vowels, with just over a third in statements and just under a third in questions.

Between themselves, speakers vary considerably in how strongly they realize phonation mode differences in statements and questions. The speaker in ikaan173 uses phonation mode most consistently, with clear strong glottal closures and releases in the majority of statements, and clear long breathy and voiceless phases in the majority of questions, as shown in the phonation mode patterns and number of instances for each pattern in Table 10. Incidentally, he is also the speaker who has been exposed to the largest range of fieldworking linguists, as he is the person to whom linguists are first sent when they arrive in the village to collect data.

The speaker in ikaan177, on the other hand, does not use creaky voice at all and uses breathy voice in both statements and questions, albeit more so in questions than in statements, as shown in the count in Table 11.

This does not mean, however, that this speaker does not distinguish between statements and questions using phonation mode. Instead, he seems to make a more subtle distinction, using modal voice and breathy phonation without voicelessness more in statements, and breathy phonation with voicelessness more in questions, as shown in Table 12.

The range of variation across speakers and contexts shows that even though prosodic markers are used by speakers with statistically significant usage patterns, there is variation hidden within this usage that hearers in real life have to deal with.

A third issue in the use of prosodic markers is that pitch onset and intensity as prosodic markers might bring to the fore a more conceptual problem: Out of context, one might not expect hearers to be able to tell if an utterance is higher or louder than usual.

Tonal differences and pitch prosodies are not marked by absolute pitch points. Instead, tone and the use of pitch in prosody are considered to be relative pitch that is compared to other tones in an utterance to establish whether it is high or low (Pike, 1948). Without a reference point, hearers might not be able to tell whether an utterance is pronounced with higher pitch. Studies by Wong and Diehl (2003) and Honorof and Whalen (2005), however, show that speakers can indeed identify lexical tones in isolation and can locate a speaker’s pitch in their pitch range successfully, even out of context.

Like tone, perceived loudness is also not marked by absolute intensity or other acoustic and articulatory correlates. Rather, loudness is perceived as a relative difference and again might not be detectable for hearers out of context. Similar to tone and pitch, however, experimental studies have shown that hearers pick up on a range of acoustic and articulatory markers to judge loudness, e.g., sound pressure level (Stevens, 1955) or vocal effort (Allen, 1971), and it is possible that speakers can do this without context, too. These studies therefore suggest that the problem of tone, pitch and intensity being relative might not be a problem after all.

In addition to perception of acoustic markers, a hearer’s familiarity with a speaker may play a role in both pitch and intensity perception. Given that the Ikaan-speaking community is very small and seems to have been very small historically, it is conceivable that all Ikaan speakers today know each other at least to some degree, and speakers would have known each other historically. As a “society of intimates” (cf. Trudgill, 2011), speakers and hearers of Ikaan may be at least somewhat familiar with each other’s natural pitch and intensity ranges and might therefore be in a position to exploit relative markers such as pitch onset and intensity to a greater degree then members or larger communities where speakers are not always familiar with each other.

The fourth issue in the use of question markers is that hearers recognized statements and questions early on, before utterance-final markers applied. The production data from the speakers shows a range of utterance-final prosodic markers: Lowering of final low tones and increased duration of final vowels in questions, and creaky and breathy termination in statements and questions respectively. Even though these markers are used consistently by speakers, hearers do not seem to have to rely on them in all cases. In the informal perception experiment conducted among speakers and hearers of Ikaan, hearers often correctly identified questions and statements well before the end of the utterance and did not seem to have to wait for utterance-final cues.

Still, the utterances produced by the Ikaan speakers show that speakers do not have to rely on morphosyntactic markers to mark statements and questions, and that they use a range of prosodic markers for this task. Yet the lack of context for some markers, the variation between and within speakers, the fact that relative utterance-initial markers may not be perceivable, and utterance-final markers may not be necessary all show that the occurrence of a single marker on its own may not be sufficient to mark questions reliably. It seems that it is only in combination that the cues manage to cover all the contexts, and that the cues are employed by speakers as a robust multi-dimensional prosodic bundle that marks statements and questions as a package.

That being said, in addition to the problems with the prosodic markers discussed above, segmental phonology is involved in Ikaan question formation, which casts some doubt on a prosody-only approach. As already seen in (16) and (17) above, some consonant-final questions are produced with a final [i] or [ɪ]. A prosodic approach cannot easily account for this vowel and a morphophonological approach, as outlined below, might be more insightful.

5.1.2. Morphophonology to the rescue? A clitic solution?

So far, the data indicates that a multidimensional prosodic package of pitch change, phonation mode changes, final lengthening, and intensity changes mark questions from statements. While not all elements apply equally in all contexts and while not all speakers employ the markers in the same way, together the prosodic cues seem to cover all contexts.

One context, however, can be interpreted differently, and that is the realization of final lengthening in consonant-final questions, as described in section 4.6. In these contexts, we encounter vowel lengthening, as in (26), but also consonant deletion with accompanying long vowels, as in (27), and vowel insertion, as in (28).⁷

The long final vowels in the questions are pronounced with varying degrees of breathy voice and voicelessness, as described in section 4.5. above. If, however, we were to interpret breathy voice and voicelessness not as surface representations of phonation mode but as a manifestation of the consonant /h/, an alternative to the analysis of phonation mode as proposed in section 4.5. arises.

Wellformedness constraints in the Ikaan phonology require segmental sequences to be made up of alternating consonants and vowels. Within words, VV or CC sequences do not occur. Across word boundaries, sequences of V ## V or C ## C are resolved. If consonants come in contact across word boundaries, an epenthetic vowel is inserted. The epenthetic vowel is always a high vowel but takes its rounding and its tone from the preceding vowel, as shown in (29).

If, however, the final consonant is /m/ or /ɡ/, the consonant is deleted, as shown in (30).

In most consonant-final utterances, statements simply end in a consonant. If the consonant is voiced, it undergoes devoicing, as in (31).

In questions, on the other hand, a vowel is added at the end, similar to the vowel insertion process in (29). The inserted vowel shows the properties of an epenthetic vowel—it is high and takes its rounding and tone from the preceding vowel. Like other final vowels in questions, it becomes breathy and/or voiceless, as in (32).

Speakers are consistent in inserting epenthetic final vowels, and no variation regarding the presence or absence of the vowel has been found. The only differences between speakers are in the actual durations of the vowel and in the presence of the various phases of devoicing. Figure 21 shows the speaker in recording ikaan171, who pronounces the consonant-final statement with a strongly released final devoiced plosive and the vowel-final statement with all three phases of phonation mode (modal, breathy, and voiceless).

Figure 21

Vowel insertion in a consonant-final question.

Utterances ending in /ɡ/ or /m/ behave differently from other consonant-final utterances and do not end in inserted vowels. Instead, they show deletion processes like that shown in (30). Final /ɡ/ surfaces and devoices in statements but is deleted in questions, as shown in (33). The final vowel in the question becomes breathy and then devoices.

Figure 22 gives waveforms and spectrograms of both the statement and the question, showing the devoiced consonant in the statement and the breathy and voiceless vowel in the question.

Figure 22

/ɡ/-final utterance ɔ̀kɪ́ɡ ‘s/he went’ as statement with final /ɡ/ (left) and question without final /ɡ/ (right).

Final underlying /m/ is deleted in both statements and questions. In both utterance types, the final sound of the utterance is the vowel that precedes the underlying /m/, as shown in (34). The final vowel in the statement is 184ms long and shows creaky voice, while the final vowel in the question is longer, with a duration of 286ms, and becomes breathy and then voiceless, as shown in Figure 23.

Figure 23

/m/-final utterance ɔ̀mâm ‘s/he laughed’ as statement (left) and question (right).

How can the presence of inserted vowels and the deletion of final consonants be explained? Instead of following a prosodic approach with phonation mode changes, we might assume that there is a sentence-final clitic = h, whose function is to mark questions. This = h ‘QU’ cliticizes to the last word in the utterance. If the utterance-final word ends in a vowel, the sequence of vowel and = h ‘QU’ might sound like [aa̤ḁ] or [ah], which is what can be observed in the data. This approach is promising for three reasons.

First, if we allow for a range of variation in the phonetic realization of /h/, a sentence-final clitic = h ‘QU’ accounts for vowel-final and consonant-final utterances. The fact that the sentence-final clitic = h ‘QU’ consists of a consonant would explain why a wellformedness constraint prohibiting consonant sequences would be violated and why, as a result, vowel insertion and consonant deletion occur to repair these violations.

Second, sentence-final clitics are not unknown in Ikaan and are attested elsewhere in the grammar. Negation is expressed (among other markers) with a sentence-final clitic = ɡ ‘NEG,’ as shown in (35).

Third, unlike the use of phonation mode changes as a strategy for making grammatical distinctions, which would be rare, clitics as grammatical markers are cross-linguistically wide-spread and well-established.

However, while a clitic analysis seems reasonable from a phonological and a cross-linguistic perspective, there are drawbacks to the clitic analysis.

Firstly, a clitic = h ‘QU’ would show highly unusual phonotactics for Ikaan. The consonant /h/ as a phoneme does not occur in final position in any other word or construction in Ikaan. The question-final position would be the only instance where the phoneme /h/ would occur in final position. Secondly, while a clitic = h ‘QU’ does account for the breathiness and voicelessness in questions, it cannot account for the contrast with creak and glottal stops in statements. A breathy vs. creaky contrast, however, integrates both contexts. Thirdly, with a segmental clitic, the tight prosody package that marks statements and questions becomes less coherent. Phonation mode on the other hand fits perfectly into a prosodic bundle. Finally, a clitic = h ‘QU’ analysis would lose the parallels that can be drawn with Gur languages, where Rialland (2009) also finds breathy phonation as a question marking strategy.

But if not because of the presence of a consonantal segmental clitic, how can the vowel insertion and vowel deletion in consonant-final utterances be explained?

From a language-internal perspective, other parts of Ikaan phonology may be able to shed light on this behaviour. While it is perfectly possible to change the phonation mode of a voiced consonant from modal to breathy and voiceless, devoicing is not a distinctive enough process in Ikaan. Final devoicing is already employed as a process to mark phrase boundaries, as in (31) and (33), where /dʒ d ɡ/ devoice at the phrase boundary to [tʃ t k] respectively. Devoicing of final consonants would, therefore, not be a sufficient marker for identifying questions. With devoicing already in use elsewhere, a language-internal reasoning could be that vowel insertion and consonant deletion are used to provide a vowel that can subsequently be gradually devoiced by breathy phonation as a question marking strategy.

From a comparative perspective, the inserted vowel could be a reflex of the low vowel that forms part of the historic lax prosody proposed by Rialland (2009). Rialland (2007, p. 49) finds reflexes of this vowel occurring in many languages in different forms, as for example in Tikar, where the final vowel has two surface forms [ɛ] and [a]. The surface form shows vowel harmony with the preceding vowel, with [ɛ] following the vowels [i e ɛ] and [a] following the vowels [u o a] (Stanley, 1991).

The inserted vowel could also be interpreted as an instance of final lengthening (see section 4.6.), as discussed for Ncam (Rialland, 2009, pp. 930–931, citing Podi 1995) and Moba (Rialland, 1984, p. 261). These languages have similar vowel insertion processes occurring with consonant-final utterances, as in Ncam in (36) or Moba in (37). For Moba, the vowel insertion is explained as a process that provides segmental material for the realization of the melody as well as the breathy termination. Both of these processes require a final vowel, which is reminiscent of a more archaic stage of the language (Rialland, 1984, p. 261; 2009, p. 933).

To sum up, a morphosyntactic solution employing a consonantal clitic seems compelling at first because it accounts for the occurrence of segmental processes. On the other hand, a clitic solution does not account for the second, contrasting phonation mode in the language and does not capture the parallels with both phonation mode changes and vowel insertion processes attested in other Niger-Congo languages that have similar prosodic packages to encode questions. A prosodic approach, including breathy voice rather than a clitic = h, captures both the language-internal prosodic package better and explains the similarities with other languages.

This prosodic approach sees pitch as a form that has many functions in the phonology, lexicon, and grammar of Ikaan. At the prosodic level, pitch functions as one of the many prosodic layers for marking yes/no questions. The prosodic packages for marking statements and questions with their various layers can be viewed as two prosodic morphemes. Each of the prosodic morphemes has a range of prosodic allomorphs that combine different layers of prosodic markers depending on the various segmental and tonal contexts (cf. Liu et al., 2013).

But where do these many dimensions of prosody come from and how can their use be explained? In a regional context this is discussed by Rialland (2007, 2009) and from a cross-linguistic perspective by Ohala (1984) and Gussenhoven (2004). Both perspectives are discussed in the following sections.

5.2.1. Inheriting lax prosodic markers from historic /-à/

Ukaan is part of the Benue-Congo family, in which Rialland (2007) finds lax prosodies in the Edoid, Cross-River, Plateau, Nupoid, and Idomoid subfamilies, as well as languages with high-pitched prosodic markers, e.g., Efik and Obolo (Cross-River), Igbo (Igboid), and Yoruba (Defoid).

Edoid has received the most attention in the more recent literature as a potential close relative for Ikaan (Abiodun, 1999; Agoyi, 2001; Elugbe, 2012). Edoid languages show strong patterns of lax prosody with low pitch markers such as final low boundary tones and a final vowel /-à/ (Rialland, 2009, p. 939), though there is no indication of breathy termination. Still, inheritance of lax prosodic markers through Edoid is conceivable. Some Edoid languages, however, follow different patterns. Yekhee (North-central Edoid), the geographically closest Edoid language to Ikaan in Rialland’s sample, uses tense prosody, marking questions with a high boundary tone. Engenni (Delta-Edoid) uses hybrid prosody with register expansion, downdrift reduction, a low boundary tone, and a final low-toned open vowel /-à/ and possibly final /-e/.

The lax and tense markers used in Edoid languages do not overlap well enough with Ikaan to single out Edoid as a particularly close match and candidate for inheritance of the lax question prosody. Low boundary tones are not attested in Ikaan, final vowels are attested but not with the same vowel quality and not with a low tone, and Edoid languages show no match for the creaky and breathy terminations found in Ikaan. Where Ikaan markers do match with features of individual Edoid languages, such as with Engenni, they do not fit the overall trend in Edoid.

5.2.2. Acquiring tense prosodic markers through contact

Ikaan speakers live in a context of rich multilingualism and language contact so that contact and convergence can easily be argued to play a role in Ikaan acquiring tense question markers. Speaker multilingualism is widespread today and it is reasonable to believe that at least some degree of multilingualism has been there for a long time. In addition, some of the oral history describes past migrations, which would have contributed to language contact and multilingualism in the past.

The main contact languages in the area are Akokoid languages, Edoid languages, dialects of Yoruba, and Ebira. In the last three generations, Nigerian Pidgin English and Nigerian English have become contact languages in some domains of language use for many but not all speakers. This highlights a problem with contact as a contributor of tense markers. Apart from Pidgin and Nigerian English, all the contact languages are Benue-Congo languages, which makes them linguistic relatives as well as contact languages. They may not be close linguistic relatives and are more likely to be distant cousins in the extended family, yet they still all descend from Benue-Congo, which in turn descends from Niger-Congo. Presumably all these languages would have inherited the same lax prosody and historic question marker /-à/. Leaving this problem aside for a moment, let us discuss these languages in terms of them being contact languages that may have introduced tense prosodic markers to Ikaan.

Akokoid languages are in close contact with Ikaan because of local trade, intermarriage, and child fostering. Unfortunately, Akokoid languages are not yet well described, so it is difficult to say anything about their contribution.

Edoid languages show predominantly lax prosodic markers (cf. above). Engenni may have contributed register expansion as a tense question marker, but this may be difficult to uphold as a contact-induced change. There is no known contact with Engenni from the oral history or other sources, and Engenni is located south of any historic migration routes that are described for the Ikaan-speaking community.

Ebira is a close contact language of Ikaan because there has been a substantial Ebira minority population in the villages for at least four generations. Many Ikaan speakers today also speak or at least understand Ebira. Ebira belongs to the Nupoid family, where Rialland finds lax prosodies in Gwari. Question prosody in Ebira is not yet described in detail, although Scholz (1976, pp. 53–54) gives the data in (38) and (39) to illustrate grammatical functions of tone.

If (38) is seen as contrasting statement and question rather than completive and question, a tonal change from mid to high could indicate a question. This is not a marker listed by Rialland (2007). In (39) a final vowel /ā/ with a mid tone distinguishes the question from the statement. Both the vowel and the lower tone are typical lax markers as listed by Rialland (2007). Scholz (1976, pp. 55–62) also discusses downdrift and final lowering, but only for statements and not in questions. With a possible tonal change from mid to high as a tense marker and a final vowel /a/ with a lower tone as lax markers, Ebira might be a hybrid prosody language. Ikaan speakers do not seem to have borrowed either of these markers into their language though, so that contact between Ebira and Ikaan cannot be seen as a contributing factor to the Ikaan hybrid prosody.

Yoruba is arguably the language with which Ikaan is in the closest contact. All Ikaan speakers in Ikakumo (Ondo) are also native speakers of the Yoruba dialect spoken in Akoko, and Yoruba is the lingua franca in the Akoko area, at least within Ondo State. In Standard Yoruba (Fajobi, 2005), yes/no questions have a higher onset pitch and a more expanded register than their corresponding statements. The last high tone may also be raised and the final syllable may be lengthened. In addition, Fajobi states that downdrift may be suspended, but does not show data to illustrate this. If Ikaan only had lax markers before its contact with Yoruba, it could indeed have acquired higher pitch onset and register expansion from Yoruba.

5.2.3. Ikaan realization of the historic /-à/ question marker

If Rialland’s proposal of a lax prosody and a historic /-à/ question marker is seen as a set of prosodic and segmental markers, it can be broken down into a bundle made up of

• specifications for duration or weight (a mora)

• specifications for segments (an open vowel)

• specifications for tone (a low tone)

• specifications for phonation mode (breathy)

If Ikaan had inherited the historic /-à / question marker, Ikaan would have lost segmental specifications since the vowels that occur in consonant-final utterances are not low but high vowels [i ɪ u ʊ]. In addition, the historic [-à] would have lost tonal specifications since there is no trace of a low tone or a low boundary tone.

Ikaan would have retained duration or weight specifications such as final lengthening and vowel insertion, and phonation mode specifications such as breathy voice and voicelessness. In addition, Ikaan would have increased the contrastiveness of breathy voice through creaky voice in the opposing declarative sentences.

5.2.4. Tense and lax prosodies: How to fit in intensity?

Assuming that we can account for hybrid prosody through inheritance from Niger-Congo and contact with Yoruba, this still leaves increased intensity as a question marker that cannot easily be included in a lax/tense distinction because it is not easily explained by laryngeal settings.

Increased intensity is the result of increased respiratory activity. A voice becomes louder if more air is pushed out of the lungs and flows across the glottis. The increased airflow blows the vocal folds apart wider and more forcefully. The vocal folds are then sucked together with more force, resulting in a more forceful and, therefore, louder glottal pulse. In addition, more airflow across the glottis may also result in higher pitch. The higher pitch in louder voices is not necessarily a result of more tension in the vocal folds. Instead, it is a side effect of the increased airflow, which leads to increased speed across the glottis, which in turn leads to lower pressure along the edges of the glottis, which in turn sucks the vocal folds together more quickly, which then leads to a higher frequency.

If intensity cannot fit into a tense vs. lax distinction, how else can we account for the fact that Ikaan questions are generally louder than statements? One possibility is to pursue the links between intensity and higher pitch. Alku et al. (2002) show that on the one hand loudness may affect pitch, in that raised intensity may lead to higher pitch. On the other hand, pitch may also affect loudness, in that speakers may increase the pitch of their voices to produce a louder voice. If the latter holds true for Ikaan, raised intensity may be a by-product of the higher onset pitch. If the former holds true, it leaves open the question why speakers produce a louder voice in the first place.

A second possibility would be to investigate how focus is realized phonetically in Ikaan. If increased intensity is a focus marker, then it could be that the entire yes/no question is in focus and is therefore louder. Increased intensity would then be a marker of the function ‘focus’ rather than a marker of the type ‘question.’

A third possibility is to re-think this classification into tense and lax markers, which is based on the physiology of what speakers do. Instead, increased intensity could be seen as part of a package with which speakers want to achieve something, such as catching the hearer’s attention by making the question stand out and persuading the hearer to answer their question. In addition to linking intensity in with other prosodic markers, this approach would have the added advantage of fitting in with the ethologically-based hearer-centred approach of the frequency code (Ohala, 1984) and the production and frequency code (Gussenhoven, 2004).