Strutt|Ratings|Sound Insulation|Speech Privacy calculates the speech privacy rating between rooms using the continuous background noise levels in the source room and the room-to-room noise level difference, and inserts the result into the active worksheet.
The speech privacy rating is calculated by calculating the sum of (NR+Dw),and comparing it to the following threshold values:
| Normal Speech | Raised Voices | Speech privacy (NR + Dw) |
| Intelligible | Clearly intelligible, possibly disturbing | Poor (<= 65) |
| Audible, intelligible if speaker and/or subject well known | Intelligible | Nominal (65 - 70) |
| Audible, but not intelligible | Audible, intelligible if speaker and/or subject well known | Good (70 - 75) |
| Just audible | Audible, but not intelligible | Very good (75 - 85) |
| Inaudible | Just audible | Excellent (>85) |