Effects of homophony on reading aloud: Implications for models of speech production

Abstract

In this paper we investigate whether homophones have shared (e.g., Dell, 1990; Levelt, Roelofs, & Meyer, 1999) or independent (e.g., Caramazza, Costa, Miozzo, & Bi, 2001) phonological representations. We carried out a homophone reading aloud task with low frequency irregular homophones and matched low frequency irregular non-homophonic controls. The ‘Shared Representation’ view predicted a homophone advantage: homophones should be read faster than their matched controls because the low frequency homophone inherits the frequency of its high frequency partner. The ‘Independent Representation’ view predicted neither an advantage nor a disadvantage: performance should be governed by the homophone's specific-word frequency. Results showed that low frequency homophones were read aloud slower than non-homophonic controls. Results were confirmed with an independent database of reading latencies (Balota, Cortese, Hutchison, Neely, Nelson, Simpson, & Treiman, 2002). Additionally, attempts to simulate the homophone disadvantage effect using current computational models of reading aloud were all unsuccessful. The homophone disadvantage effect constitutes, therefore, a new challenge for all computational reading models to date.

Keywords:

• Homophone representation
• Homophone reading aloud
• Models of reading aloud
• Dual Route Cascaded (DRC) model

Acknowledgements

This paper was prepared while Britta Biedermann was supported by an International Macquarie University Research Scholarship (iMURS) and a Macquarie University Research Fellowship MQRF. Lyndsey Nickels was funded by an Australian Research Council QEII fellowship and an NHMRC Senior Research Fellowship. Max Coltheart was funded by Australian Research Council Special Research Centre and Federation Fellowship grants.

Notes

¹Although Caramazza et al. (2001) do use a homophone reading aloud task, we did not add their experiment to the list of evidence for effects of homophony on reading aloud as the authors only used a delayed reading task.

²However, the argument here is somewhat circular, as the reason Wheeldon and Monsell (1992) argue that priming occurs in the links is because they assume a single homophone representation.

³These experiments and those focusing on ‘multiplicity of meaning’, all use homographic homophones – words where a single orthographic form maps onto multiple meanings. Our experiments involve words (heterographic homophones) where for reading there is no ambiguity or multiplicity of meaning – an orthographic form maps onto a single meaning (e.g., ‘quay’). This distinction is critical: ambiguous phonology (/ki:/) and ambiguous orthography (e.g., ‘bank’) has different implications for reading.

⁴This is the same reasoning we used in our experiment: irregular homophones cannot be read via the grapheme-phoneme correspondence routine, the reader is forced to read via the lexical routine.

⁵Although Rodd (2004) frequently refers to her stimuli as ‘irregular’ and ‘regular’ (e.g., see her Figure 1, p. 442). However, in the Appendix, Rodd based her stimuli on a different distinction: ‘inconsistent’ and ‘consistent’. According to the DRC criteria, Rodd's consistent words were all regular (66 out of 66), but her inconsistent words were not all irregular. According to the DRC definition of ‘regular’, 15 out of 66 inconsistent words were regular, which Rodd classified as irregular. Therefore, it might be possible, that the effects Rodd found, could have been due to regularity.

⁶This is the key distinction between heterographic homophones and homographic homophones (homophonic homographs): homographic homophones have a single orthographic form mapping onto multiple meanings. The latter being those words focused on in the literature on multiplicity of meanings.

⁷However, even were we to assume independent homophone representations, the line of argument will still hold – that semantic and lemma representations can lead to a homophone disadvantage in reading aloud of irregular heterographic homophones.