Clear speech

Clear speech has been studied in 2 papers since 2017: 2 observational studies in people. The newest paper, Oct 28, 2017: “Intelligibility of Noise-Adapted and Clear Speech in Child, Young Adult, and Older Adult Talkers”.

2 papers study it2 findingsUpdated Oct 28, 2017

“Noise-adapted and clear speech significantly enhanced intelligibility for young adult listeners.”

None of its findings points the other way.

What did studies of Clear speech find?

Studies of Clear speech measured 2 outcomes; the most studied are speech intelligibility (1 study) and speaking rate (1).

Speech intelligibility

upin humans1

1 study

Clear speech improves speech intelligibility in humans.
“Noise-adapted and clear speech significantly enhanced intelligibility for young adult listeners.”
Human trialin noise at -5 dB signal-to-noise ratio
Intelligibility of Noise-Adapted and Clear Speech in Child, Young Adult, and Older Adult Talkers
Journal of speech, language, and hearing research : JSLHROct 28, 2017

Speaking rate

downin humans1

1 study

Clear speech decreases speaking rate in humans.
“Older adults produced the slowest speaking rate, longest pauses, and smallest increase in F0 mean, 1-3 kHz energy, and SPL when speaking clearly.”
Human trialn = 10
Acoustics of Clear and Noise-Adapted Speech in Children, Young, and Older Adults
Journal of speech, language, and hearing research : JSLHROct 28, 2017