Which factors will affect speech intelligibility?

Which factors will affect speech intelligibility?

• A. Distortion
• B. Reverberation
• C. Sound pressure level
• D. All of the above

Answer: (D)

Speech intelligibility depends on how clearly a spoken message can be heard and decoded in the listening environment. Distortion changes the shape of the audio signal, which can blur the distinct consonant and vowel cues listeners rely on to identify words, making speech harder to understand. Reverberation causes overlapping reflections that smear the timing of sounds, eroding the rapid cues that help separate syllables and words, especially in larger or hard-surfaced rooms. Sound pressure level affects how well the speech stands out from background noise; too quiet, and noise masks the message; too loud, and it can cause discomfort or distortion, though a higher level typically improves clarity up to a point. In fire alarm situations, you want speech that remains intelligible despite noise and room acoustics, so all these factors come into play.