Phenomenal Insights: Extraordinary auditory hallucinations–Thought sonorisation

Gedankenlautwerden refers to the experience of hearing one’s own thoughts spoken out loud while having the thoughts, in other words, the two are simultaneous. In contrast, the term Echo de la pensée refers to thoughts heard after they have been produced – effectively a ‘thought echo’. Both experiences are subsumed under thought sonorisation and because of this the nuanced difference is lost. In today’s clinical practice, this lack of specificity is even greater because none of these terms, not even thought sonorisation, are in common usage. Instead, these phenomena are broadly described as auditory hallucinations or worse still, simply referred to as ‘voices’.

Like many German words Gedankenlautwerden is a composite word and a direct translation of each word separately reads, ‘thoughts becoming loud’ or ‘thoughts becoming audible’. In German psychiatry, Gedankenlautwerden was first characterised by August Cramer (1860–1912) ( Figure 1 ), who described it as ‘the patient’s sensation that all their thoughts are spoken within their chest’, that ‘thoughts are repeated by others and cried out loudly’ or thoughts that ‘resonate with some accidental rustling sound in the external world’ (Cramer, 1889). He renamed the latter concept as indirektes (indirect) Gedankenlautwerden – suggesting that initially the term was used more broadly. Carl Wernicke (1848–1905) noted this inconsistency in usage and, cautioning that Gedankenlautwerden would lose its value as an elementary symptom, ¹ proposed that it should be understood as narrowly as possible. Hence, he advanced the definition: ‘thoughts that are recognised by the patient as their own, sounding aloud at certain occasions such as when the patient is reading or writing’.

Figure 1.

Johann Baptist August Cramer (1860–1912).

Cramer provides interesting examples of these phenomena from patient reports and describes voices coming from patient’s feet, out of their chest (often associated with a feeling of tension in the chest – Praecordialangst), in front of their own and others’ ears, and from ambient noise in the environment – for example, running water, the wind, a clock ticking and a spinning wheel. One patient even reported wanting to cut off his beard to prevent voices getting ‘caught’ in there.

Cramer postulated the aetiology of Gedankenlautwerden as a connection between the musculature (or ‘muscular sense’ of speech – Muskelsinn des Sprachapparates), and thought processes. However, Cramer’s colleagues rejected his theory of a connection, even though patients often explain the origin of their voices by referring to these structures. For example, one patient complained of her ‘talky-talky tongue’ because she felt speech movement in her tongue when she had auditory hallucinations. Even in healthy subjects, sub-vocal speech movements have been observed when thinking or reading silently, and hence, it is not surprising that slight movements of the lips, tongue and laryngeal muscles often occur in patients with auditory hallucinations. Extending the phenomenon further, in 1892 Dr O Klinke coined the term ‘Gedankensichtbarwerden’ (thoughts becoming visible), to capture a patient reporting not only hearing their thoughts out loud, but also seeing their thoughts in actual letters or stenographic print.

In French psychiatry, the first description of Echo de la pensée, thought echo, was attributed to Jules Séglas (1856–1939), who stated that ‘among the images of internal language, hearing then became so intense that it is externalized in the form of hallucination, reproducing the intimate thoughts of the patient: it is the phenomenon of the echo of thought’. Séglas distinguished several forms of these thoughts: ‘the insane person, describing what he experiences, complains that his ideas are being stolen, and that others repeat what he is thinking, and that they are aware of his feelings before he has had time to think’.

Unlike his contemporary, Cramer, Séglas did not give the clinical description any aetiological significance. As a student of the Salpêtrière Hospital school in Paris, Séglas remained faithful to Jules Baillarger (1809–1890), who had distinguished hallucinations as those occurring in outer space (perceived as external) and those occurring in inner space (perceived as internal), thus positioning thought echo in the latter category (Baillarger 1846).

Twenty years later, Gaëtan Gatien Clérambault (1872–1934) considered thought echo to be a basic component of hallucinatory psychosis. Furthermore, following Wernicke, who regarded stimulation of sensory centres as necessary to elicit hallucinations, Clérambault was convinced of the mechanical nature of thought echo with aetiological components akin to a lesion (De Clérambault, 1927).

However, those at the Henri Claude School (1869–1945) at Sainte-Anne Hospital Paris questioned this biological/mechanistic view of hallucinations. Hence, Charles Durand (1910–2001), who wrote his thesis on thought echo, proposed a new definition: ‘an illusion of duality and strangeness in the perception of inner speech’ (Durand, 1941). He distinguished neurological forms (lesions) from psychiatric forms, which were related to the dysregulation of functional brain networks and psychic dimensions.

This refinement of the acoustic-verbal hallucinations concept (EY), and particularly of the various forms of thought echo, perhaps warrants neuroscientific inquiry. It is possible that the neuronal networks involved are different according to the semiology of the hallucinations, as some brain imaging studies are beginning to indicate (Plaze et al. 2011). However, this will only be possible if these terms are in clinical use and applied appropriately with sophistication and nuance.