A verse is not written for the room; it is written for the cheapest chair in it, and that chair hears about eighteen decibels less of you than the front one does. In a calm room that gap can sit exactly where an understood word becomes a guessed one. The work happens on the page, before the night.
The last chair is eighteen decibels away
The fall-off is a rate a singer can use: six decibels for every doubling of the distance from the source. Stage to back row in a long forty-chair room is three doublings, one metre to eight, and the voice arrives eighteen decibels down. Write the assumptions down: a voice at 55 dB at one metre, inside the 40 to 60 dB band of normal conversation, and a very calm room at 25 dB. The last row then receives about 37 dB of voice against 25 dB of room, a margin of 12 dB, the ratio at which speech is usually fully intelligible with background noise between 35 and 100 dB. A room already at conversation level leaves the last row nothing.
| Distance from the singer | Doublings | Voice level | Margin over the room |
|---|---|---|---|
| 1 m | none | 55 dB | 30 dB |
| 2 m | one | 49 dB | 24 dB |
| 4 m | two | 43 dB | 18 dB |
| 8 m | three | 37 dB | 12 dB |
Reflections hand some of the level back, so treat the result as a floor.
What does the room do to a consonant?
Reverberation smears a sung line across time, and not evenly. What is steady, a vowel held at the end of a phrase, comes back flattered. What is quick comes back buried: stop consonants, glides, the bend between vowels, the small cues of pitch and length that carry the meaning. A live room hands the feeling over free and keeps the story as its fee. The blur can be rated rather than argued: the intelligibility standards ask for a Speech Transmission Index above 0.6, an articulation loss of consonants below 10 per cent and a clarity index C50 above 3 dB. You will measure none of these before a forty-chair night; what a low ceiling does to that blur can be estimated with a tape measure. The ear forgives roughness; what it does not forgive is a word that never arrived, and force will not deliver it.
Two passes, one verse
The test costs one volunteer and one pencil. Sit in the last row; have the volunteer read or sing the verse at show volume, and write down every word you do not get. Run the pass again with three people talking softly by the door. The first pass measures the building; the second measures the evening, because the floor rises once the door is propped and the till is live, the inventory the house's noise floor already holds. Words lost in both passes die in the room; words lost only in the second die in the babble.
What do you change when a word is lost twice?
A word lost twice is a writing problem, not a diction problem. Speech aimed at a struggling listener slows, pauses longer, aims its vowels and puts weight back on its consonants; speech that merely fights noise gets louder and a shade higher; speech that shouts loses information about its own sounds. The lyric has the same choice. Put the sense on stressed syllables and open vowels; keep one idea to a line; end on a word that can be sung long; keep runs of small unstressed words away from the end of a line, where the blur lands hardest; and repeat, once, later, the line that carries the story. The desk built a line in both states. Before: "and there was a word that I owed you and I never got round to it", which ends on its weakest syllable and buries its one idea in connectives. After: "stay was the word I owed you, and I paid it late", which loads "stay" and "owed" and ends on a vowel that can be held. A verse built this way, four lines at a time, is sketched in the four-line verse.
Five minutes in the empty room
Run these before the doors, while the volunteer is still in the room.
- Read the verse once at show volume from the last chair and mark every word that does not arrive.
- Add three people talking softly by the door; the new losses belong to the evening, not the verse.
- Count the metres from your stool to the last row, double three times at six decibels a doubling, and know what the far end gives up.
- Find the line that ends on its weakest word, swap the ending for a word you can hold, and test the swap from the same chair.
- Decide which song ends quietest, and whether its last line still lands if it loses three words on the way.
Sources
- Wikipedia, article "Speech intelligibility", speech intelligibility, consulted 5 September 2026.
- Wikipedia, article "Sound pressure", sound pressure, consulted 5 September 2026.
- The worked examples are the desk's own arithmetic, redoable from the assumptions above.