Interface

Geva Inner Speech Battery

A test battery for inner speech, relevant to communication and brain-computer interface candidacy.

By Claire White

What does the Geva battery measure?

The battery probes inner speech, the silent use of language in the mind. Each of its five tasks asks a question that can only be answered by retrieving how a word sounds, without ever saying it. English spelling and English sound diverge often enough that these questions cannot be answered from the letters alone.

The five tasks in the Geva inner speech battery and what each one asks
TaskWhat it asks
Rhyme judgement, picturesDo the names of these two pictures rhyme?
Rhyme judgement, written wordsDo these two written words rhyme?
Homophone judgement, wordsDo these two written words sound the same?
Homophone judgement, non-wordsDo these two invented letter strings sound the same?
Lexical stress judgementWhich syllable of this written word carries the stress?

Inner speech draws on the brain’s speech-planning and speech-perception systems. Lesion mapping in people with post-stroke aphasia located it to the left pars opercularis in the inferior frontal gyrus and to white matter adjacent to the left supramarginal gyrus. It is also one of the signals studied in brain-computer interfaces that aim to restore communication.

What does a Geva battery result mean?

Performance on each task is compared against the normative sample rather than sorted into bands. The battery publishes no cut-offs and no severity grades, because it was built to describe natural variation in inner speech among healthy adults, and that variation is wide. Education correlated with performance on some tasks. Age and gender did not.

What the result adds is the gap between inner and outer speech. Those two can come apart in either direction in aphasia, so a test of speaking aloud cannot stand in for this one. It is reference information, and in research settings it informs work on communication driven by inner speech.

How the Geva battery is administered

Administered by
A researcher or clinician
Format
Five silent judgement tasks. Nothing is spoken aloud.
Norms
Healthy native British English speakers aged 20 to 72
Language
English. The tasks depend on English spelling and stress, so they do not transfer directly to other languages.

Which conditions is the Geva battery used for?

Related instruments

Inner speech questions, answered

What is inner speech?

The voice you use to think in words without saying them. Reading a sentence and hearing it in your head is inner speech. So is rehearsing a phone number, or knowing that two words rhyme before you have spoken either of them.

How do you test something silent?

By asking a question that can only be answered if the sound of the word was retrieved. Whether two written words rhyme cannot be worked out from their spelling alone, because English spelling and English sound come apart constantly. Answering it requires generating the sound internally, so a correct answer is evidence the internal sound was available.

What does the Geva battery measure?

Five things, each a silent judgement. Whether two pictures have names that rhyme, whether two written words rhyme, whether two written words sound the same, whether two invented letter strings sound the same, and which syllable of a written word carries the stress. Together they probe access to the auditory word form.

Why does inner speech matter in aphasia?

Because it can come apart from speaking, in either direction. Some people with severe speech output retain inner speech, and some people who speak more fluently have impaired inner speech. A test of speaking aloud cannot tell those apart, and the difference matters for how someone is treated and for what they can do with a device that reads intention rather than movement.

Is the Geva battery a clinical test I can buy?

No. It is a research battery published in a journal article, not a commercial kit. There is no manual to purchase and no certification to obtain. Its norms come from healthy British English speakers aged 20 to 72.

Does the Geva battery diagnose anything?

No. It characterises one specific ability and produces reference information. Diagnosis stays with your clinician.

Evidence, psychometrics and provenance

Created by Sharon Geva and Elizabeth Warburton, who published the battery in 2019, building on their earlier work mapping inner speech in people with aphasia.

Psychometrics

The 2019 paper reports normative performance rather than reliability coefficients, so no test-retest or internal consistency figure is available to quote.

Normative sample
Healthy native British English speakers aged 20 to 72, 28 to 97 people per task (Geva and Warburton, 2019)
Effect of education
Correlated with performance on some tasks
Effect of age and gender
No effect found in the normative sample
Lesion correlates
Left pars opercularis and white matter adjacent to the left supramarginal gyrus (Geva et al., 2011)

References

  1. 1.Geva S, Warburton EA. A test battery for inner speech functions. Arch Clin Neuropsychol. 2019;34(1):97-113.
  2. 2.Geva S, Jones PS, Crinion JT, Price CJ, Baron JC, Warburton EA. The neural correlates of inner speech defined by voxel-based lesion-symptom mapping. Brain. 2011;134(Pt 10):3071-3082.
  3. 3.Langland-Hassan P, Faries FR, Richardson MJ, Dietz A. Inner speech deficits in people with aphasia. Front Psychol. 2015;6:528.
  4. 4.Kunz EM, Abramovich Krasa B, Kamdar F, et al. Inner speech in motor cortex and implications for speech neuroprostheses. Cell. 2025;188(17):4658-4673.
  5. 5.Fama ME, Turkeltaub PE. Inner speech in aphasia: current evidence, clinical implications, and future directions. Am J Speech Lang Pathol. 2020;29(1S):560-573.

This assessment uses a validated instrument and is reference information, not a diagnosis.