Bibliometric analysis, systematic review of literature, and meta-analysis on the effect of amplification on voice production among teachers.
Lady Catherine Cantor-Cutiva, Karol Acevedo, Marco Guzman and 5 others
PMID 40609491WHAT IT FOUND
Voice amplification did not significantly reduce vocal strain metrics like pitch, loudness, or phonation time in teachers.
Evidence remains inconclusive due to varied study designs and devices, so amplification alone is not a proven solution for voice disorders.
Key findings
01Meta-analysis showed no statistically significant effect of amplification on fundamental frequency, sound pressure levels, or phonation time percentage.
02The evidence base is considered inconclusive and not strong enough to draw definitive conclusions for implementation.
03A majority of the included studies were rated as weak quality, and heterogeneity across studies was a concern.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
High heterogeneity across the 20 included studies due to different designs, sample sizes, and types of amplification devices. Most included studies (60%) were rated as weak quality. Small sample sizes in several of the primary studies limit generalizability. The review focused only on three acoustic metrics and did not assess self-reported voice symptoms or vocal fatigue.
Declared interests
No specific funding sources or conflicts of interest are declared in the provided text.
The easy way to misread this
Do not interpret the lack of statistical significance as proof that amplification is useless. The studies were too varied and low-quality to rule out small benefits, but they also do not support it as a primary intervention.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →