Functional Speech and Voice Symptoms: Diagnostic Technique Inventory

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Cross-task comparison · Stuttering and prosody · Voice and laryngeal assessment

Diagnostic techniques at a glance

Automatic versus requested speech

The speech-language clinician compares ordinary conversation with requested speech. A specific inconsistency may support functional communication symptoms. Task dependence also occurs in neurological speech disorders, so the comparison requires a full language and motor-speech assessment. [1][2]

Phonation during cough or laughter

Voice may be available during spontaneous coughing or laughing despite difficulty producing requested speech. This can demonstrate preserved capacity but does not independently identify the cause. Do not force coughing or trigger distress to obtain it. [1][2]

Singing versus speech

A clinician may compare comfortable singing and speaking where suitable. Different access to voice can be informative, but improvement with singing also occurs in non-functional disorders. This is a supportive comparison, not a specific diagnostic sign. [1]

Distractibility and variability

Speech or voice may change during an alternative task or a change of attention. Case-series and consensus descriptions support this observation, but spontaneous fluctuation is insufficient for diagnosis and need not occur in every functional presentation. [1][2]

Stuttering and prosody assessment

The clinician examines fluency, rhythm, stress and their consistency across tasks. Particular incongruities can contribute to diagnosis, but acquired neurological stuttering and developmental differences need assessment. No single stuttering pattern proves FND. [1][2]

Articulation and language comparison

Reading, repetition, naming and conversation help determine whether the main difficulty concerns speech movement, language or voice. A specific internal inconsistency may support a functional formulation; normal performance on one task does not exclude aphasia or other disease. [1]

Laryngoscopy and stroboscopy

Visualization of the vocal folds assesses motion, closure and structural disease. Findings help interpret task-dependent voice changes and coexisting conditions. A normal laryngeal examination by itself does not diagnose functional voice symptoms. [1]

Immediate response to a speech or voice cue

A gentle clinician-led cue may reveal more accessible speech or phonation. This is a described assessment observation, not a validated diagnostic trial. Improvement does not prove FND, and lack of improvement does not rule it out. [1][2]

Research and Sources

The consensus document and descriptive case series support clinical reasoning, not universal accuracy estimates for each entry. The digital-marker research discussed on the overview is an emerging research note, not an added clinical inventory entry.

Citation	Full citation
[1]	Baker J, Barnett C, Cavalli L, et al. Management of functional communication, swallowing, cough and related disorders: consensus recommendations for speech and language therapy. Journal of Neurology, Neurosurgery & Psychiatry. 2021;92(10):1112–1125. FND-CIT-0025. https://doi.org/10.1136/jnnp-2021-326767
[2]	Chung DS, Wettroth C, Hallett M, Maurer CW. Functional Speech and Voice Disorders: Case Series and Literature Review. Movement disorders clinical practice. 2018;5(3):312-316. DOI. PMID: 30800702. FND-CIT-0169.