Siren loudness has risen from 95 to 122 dBA over a century
Evidence
Since the introduction of the disc siren in North America, the principal change has been in the volume of sound output. We have measured the siren on a 1912 vintage vehicle at 88 to 96 dBA at 3½ meters. By 1960 siren intensity had risen to 102 dBA at 5 meters. In recent years a new type of yelping siren has been introduced for emergency vehicles, measuring 114 dBA at the same distance. The United States is now manufacturing a yelping siren for police car use which measures 122 dBA at 3½ meters. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 561 (
#corroborates, via linked claim)
When a simple solution to a problem exists, an administrator will usually prefer a gummy one. I have already suggested that a simpler way to calculate the ambient noise increase would be to measure the sound signals of the community. The assumption would be that the level of ambient noise would rise in proportion to social signals, which must always remain above it. We did this for Vancouver by measuring the sound levels of different fire engine sirens, beginning with a 1912 La France device (88-96 dBA) and concluding with the newest 1974 siren (114 dBA), all measured at a distance of 3½ to 5 meters. This showed that the signals of emergency vehicles had risen some 20 to 25 decibels in sixty years, or nearly half a decibel per year on the average. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 625 (
#expands, via linked claim)
An International Whaling Commission survey found that underwater noise levels have doubled every ten years over the past six decades in some areas of the world’s oceans. A survey off Point Sur in California showed a 15 dB, or thirty-two-fold, increase in ocean noise between 1950 and 1975. — George Michelsen Foy, Zero Decibels, 354 (
#exemplifies, via linked claim)
Categorization
- corroborated: 2 independent passages support this claim
- XREF: connects to: Siren volume has risen steadily across a century. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 561; Emergency siren loudness proxies track ambient noise rise over decades — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 625; Ocean ambient noise levels have risen dramatically over the past sixty years — George Michelsen Foy, Zero Decibels: The Quest for Absolute…, 354
Related
- Siren volume has risen steadily across a century. (similarity 0.96)
- Emergency siren loudness proxies track ambient noise rise over decades (similarity 0.94)
- Ocean ambient noise levels have risen dramatically over the past sixty years (similarity 0.84)
Broader Connections
- Siren volume has risen steadily across a century.
#corroborates(0.95) — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 561 - Emergency siren loudness proxies track ambient noise rise over decades
#expands(0.80) — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 625 - Ocean ambient noise levels have risen dramatically over the past sixty years
#exemplifies(0.50) — George Michelsen Foy, Zero Decibels, 354