- There are a number of ways of classifying speech privacy.
- Confidential privacy - meaning of spoken message is unintelligible to nearby coworkers who can only hear muffled words, and this doesn't cause noise distraction from work.
- Normal privacy - speech volume level isn't distracting to work, and most sentences are unintelligible.
- Transitional privacy - most sentences are intelligible to co-workers, and are distracting, stressful and impair work performance.
- A number of issues related to speech privacy are:
- Problems of speech privacy stem from a high signal/noise ratio.
- Speech privacy depends upon the intelligibility of encroaching sound.
- Most of the intelligible speech lies between 2Khz - 4Khz, irrespective of gender.
- Women have voices ~1 octave higher than men
- Speech privacy can be improved by:
- decreasing the signal strength (talk more quietly, increase distance, absorbent surfaces)
- increasing the noise level (sound conditioning/noise masking)
See also: Sound Masking.