PhD thesis - School of Informatics - University of Edinburgh

Chapter 6. Other Potential Applications 151
Eklund and Lindström (2001) conclude that there is a clear correlation between
increasing educational level and closer approximation of the foreign language pronun-
ciation. A high educational standard of subjects correlates with a high degree of xeno-
phone inclusions. On the other hand, Ljung (1998) 1 reports negative attitudes towards
foreign expressions correlating with a high level of education. Lindström and Eklund
(2002) argue that this discrepancy can be explained by the fact that Ljung (1998) bases
his observations on subjects who understood the purpose of the experiment. When be-
ing asked explicitly to read a sentence containing foreign inclusions, highly educated
people may make a conscious decision to preserve their native tongue from foreign
influence and adapt the inclusion’s pronunciation to patterns of their own language.
The same highly educated subjects might be more prone to render foreign inclusions
according to the source language when unaware of the scenario.
Lindström and Eklund (2000) also infer from their findings that a Swedish TTS
system must be capable of producing the appropriate pronunciation of foreign names
and words in running Swedish texts, as users would have difficulties in accepting a
TTS system with a lower level of competence than their own. Does this mean that
Swedish listeners would prefer a TTS system which at least produces those foreign
speech sounds correctly that are not included in the phonological inventory of their
native language? How would they react to a system that pronounces all foreign speech
sounds, including those with similar counterparts in the speaker’s language, authenti-
cally according to the phonetic and acoustic characteristics of the foreign language?
Would highly educated people more easily accept such synthesised speech? How
would listeners perceive a system that adjusts all foreign speech sounds to sounds in
their native language? Provided that this type of synthesis output is intelligible, would
less highly educated listeners find it easier to accept it? Only a controlled and de-
tailed perception study in terms of naturalness, intelligibility, pleasantness etc. would
assist in evaluating the benefit of adding certain xenophones into the inventory of a
TTS system. Lindström and Eklund (2000) do hypothesise that a low inclusion level
of xenophones may not appear primarily in the intelligibility dimension, but portray
itself to the listener as a synthesiser with a low level of education. On the other hand,
if too many xenophones are added, some users might be at a disadvantage, particularly
with regards to non-English foreign inclusions.
1 Quoted in Lindström and Eklund (2002)