Noise Levels
For satiable communication, the average speech level should exceed that of an interfering noise by 6dB; lower sound:noise ratios are rarely acceptable (Moore, 1997). Manifesting in a wide frequency range, speech is quite resistant to many types of masking frequency cut-off—Moore reports, for example, that a band of frequencies from 1000 Hz to 2000 Hz is sufficient (sentence articulation score of about 90%).
| Quantity to be measured | Unit of measurement | Good values |
|---|---|---|
| STI | Intelligibility (international known) | > 0.6 |
| CIS | Intelligibility (international known) | > 0.78 |
| %Alcons | Articulation loss (popular in USA) | < 10% |
| C50 | Clarity index (widespread in Germany) | > 3 dB |
| RASTI (obsolete) | Intelligibility (international known) | > 0.6 |
Word articulation remains high even when only 1–2% of the wave is unaffected by distortion:
Read more about this topic: Intelligibility (communication)
Famous quotes containing the words noise and/or levels:
“But what it was, alas, I cannot tell,
Because of it I had no perfect view;
But as it was, by guess, I wish it well
And will until I see the same anew.
Shadow, or she, or both, or choose you whither:
Blest be the thing that brought the shadow hither.”
—Unknown. I Heard a Noise and Wishèd for a Sight (l. 13–18)
“The country is fed up with children and their problems. For the first time in history, the differences in outlook between people raising children and those who are not are beginning to assume some political significance. This difference is already a part of the conflicts in local school politics. It may spread to other levels of government. Society has less time for the concerns of those who raise the young or try to teach them.”
—Joseph Featherstone (20th century)