Decibel Limits: Ayer vs Cambridge
How do decibel limits rules compare between Ayer, MA and Cambridge, MA?
Ayer has fewer restrictions than Cambridge.
Ayer, MA
Middlesex County
Middlesex County follows Massachusetts 310 CMR 7.10 which caps sound at 10 dBA over ambient at property lines. Many cities add hard numeric limits of 65 dBA day / 55 dBA night in residential zones.
View full Ayer rules →Cambridge, MA
Middlesex County
Cambridge enforces numerical decibel limits: 60 dBA day and 50 dBA night at residential receptors, with a 5 dBA penalty for tonal or impulsive sounds.
View full Cambridge rules →Key Facts Comparison
| Fact | Ayer | Cambridge |
|---|---|---|
| State floor | 10 dBA over ambient | - |
| Residential day | 60-65 dBA typical | - |
| Residential night | 50-55 dBA typical | - |
| Commercial | 70 dBA typical | - |
| Measurement | At property line, Type 2 meter | Type 2 meter at property line |
| Day Limit | - | 60 dBA (7 AM to 10 PM) |
| Night Limit | - | 50 dBA (10 PM to 7 AM) |
| Tonal Penalty | - | Plus 5 dBA |
| Low-Frequency | - | Separate assessment available |
Highlighted rows indicate differences between cities.
Ayer FAQ
What is the quietest limit in Middlesex County?
Cambridge applies 50 dBA nighttime in residential zones, among the strictest in the county.
Does the state rule trump my town?
No, but it is the minimum. Cities can set stricter limits but cannot exceed the state 10-dBA-over-ambient cap.
Cambridge FAQ
What is a dBA versus dB?
dBA is A-weighted decibels, which adjusts for human hearing sensitivity. Cambridge uses dBA for most limits, with special handling for low-frequency sound.
How loud is 50 dBA?
About the level of a quiet refrigerator or light rainfall, roughly 15 feet from a normal conversation.
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