decibel-shield

Answers "how loud is Tokyo", "noise level in Mumbai", "is Delhi louder than London". Estimated day/night noise ranges (dB), rank among 50 major world cities, dominant noise sources and a confidence label, with WHO guideline context (53 dB Lden / 45 dB Lnight). Estimates synthesized from published sources, not measurements. For US cities computed from federal data use get_us_city_noise_exposure; for measured Europe data use get_europe_city_noise.

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string",
      "description": "City name, e.g. \"Tokyo\" or \"São Paulo\""
    }
  },
  "required": [
    "city"
  ]
}

{
  "type": "object",
  "properties": {
    "rank": {
      "type": "integer",
      "description": "Rank among the 50 cities (1 = loudest)"
    },
    "city": {
      "type": "string"
    },
    "country": {
      "type": "string"
    },
    "day_range_db": {
      "type": "string",
      "description": "Estimated daytime range, e.g. \"60-72\""
    },
    "night_range_db": {
      "type": "string"
    },
    "dominant_noise_sources": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "confidence": {
      "type": "string",
      "enum": [
        "high",
        "med",
        "low"
      ]
    },
    "page_url": {
      "type": "string",
      "description": "Detail page when available"
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "rank",
    "city",
    "country",
    "day_range_db",
    "night_range_db",
    "confidence"
  ]
}

Answers "loudest cities in the world", "noisiest cities ranking", "which city has the worst noise pollution". 50 major world cities ordered by estimated daytime noise, loudest first — estimates synthesized from published sources, not measurements. For "loudest cities in the US" or "quietest cities in the US" use get_us_city_noise_exposure (computed from federal BTS data); for Europe use get_europe_city_noise (measured).

{
  "type": "object",
  "properties": {
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 50,
      "description": "How many cities to return (default 10)"
    }
  }
}

{
  "type": "object",
  "properties": {
    "cities": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "rank": {
            "type": "integer",
            "description": "Rank among the 50 cities (1 = loudest)"
          },
          "city": {
            "type": "string"
          },
          "country": {
            "type": "string"
          },
          "day_range_db": {
            "type": "string",
            "description": "Estimated daytime range, e.g. \"60-72\""
          },
          "night_range_db": {
            "type": "string"
          },
          "dominant_noise_sources": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "confidence": {
            "type": "string",
            "enum": [
              "high",
              "med",
              "low"
            ]
          },
          "page_url": {
            "type": "string",
            "description": "Detail page when available"
          }
        },
        "required": [
          "rank",
          "city",
          "country",
          "day_range_db",
          "night_range_db",
          "confidence"
        ]
      }
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "cities"
  ]
}

Answers "how loud is a hair dryer", "how many decibels is a chainsaw", "is 85 decibels loud", "how loud is 80 decibels". Decibel level and hearing-risk guidance for everyday sounds (whisper, conversation, traffic, lawn mower, concert, jet engine...), every figure sourced to CDC/NIOSH/NIDCD/ASHA published tables. Input is a sound name; if you already have a dB number and want safe listening time, use safe_exposure_time.

{
  "type": "object",
  "properties": {
    "sound": {
      "type": "string",
      "description": "Sound to look up, e.g. \"lawn mower\" or \"subway\""
    }
  },
  "required": [
    "sound"
  ]
}

{
  "type": "object",
  "properties": {
    "matches": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "sound": {
            "type": "string"
          },
          "db_low": {
            "type": "number"
          },
          "db_high": {
            "type": "number"
          },
          "risk": {
            "type": "string"
          },
          "risk_note": {
            "type": "string"
          },
          "source": {
            "type": "string"
          }
        },
        "required": [
          "sound",
          "db_low",
          "db_high",
          "risk",
          "source"
        ]
      }
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "matches"
  ]
}

Answers "how long can I listen to 100 dB", "is 85 dB dangerous for 8 hours", "how long at a concert before hearing damage". Maximum daily safe exposure time for a sound level per NIOSH's recommended exposure limit: 85 dB(A) for 8 h, 3 dB exchange rate (88 dB → 4 h, 100 dB → 15 min). Input is a dB number; to get the dB of a named sound first, use lookup_sound_level.

{
  "type": "object",
  "properties": {
    "db": {
      "type": "number",
      "description": "Sound level in dB(A), e.g. 95"
    }
  },
  "required": [
    "db"
  ]
}

{
  "type": "object",
  "properties": {
    "db": {
      "type": "number"
    },
    "safe_duration_hours": {
      "type": "number",
      "description": "NIOSH max daily exposure in hours; null when not applicable"
    },
    "summary": {
      "type": "string"
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "db",
    "summary"
  ]
}

Answers "loudest cities in the US", "quietest cities in the US", "how noisy is Boston", "what share of Miami hears highway noise". Share of residents exposed to ≥60 dB / ≥70 dB transportation noise for all 297 US cities of 100,000+ residents, computed from the federal BTS 2020 National Transportation Noise Map, not estimated. Pass a city for detail, omit for the ranking. Street address → get_address_noise; neighborhoods → get_neighborhood_noise.

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string",
      "description": "US city name, e.g. \"Boston\" (optional)"
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 297,
      "description": "How many ranked cities when no city is given (default 10)"
    }
  }
}

{
  "type": "object",
  "properties": {
    "cities": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "rank": {
            "type": "integer"
          },
          "city": {
            "type": "string"
          },
          "state": {
            "type": "string"
          },
          "population": {
            "type": "integer"
          },
          "pct_ge60_db": {
            "type": "number",
            "description": "Share of residents exposed to >=60 dB (%)"
          },
          "pct_ge70_db": {
            "type": "number"
          }
        },
        "required": [
          "rank",
          "city",
          "state",
          "pct_ge60_db"
        ]
      }
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "cities"
  ]
}

Answers "how loud is my neighborhood", "noise map by address", "how noisy is this address", "noise level in ZIP 78701". Modeled transportation noise (road + rail + aircraft, 24-hour average LAeq dBA) at a US street address, a 5-digit ZIP (sampled at the ZIP Code area center, approximate) or lat/lng, sampled block-by-block from the federal BTS 2020 National Transportation Noise Map. Returns a modeled dBA band, NOT a measurement; "below 45 dBA" means no modeled freeway/rail/flight path nearby (model floor, not silence). Continental US only.

{
  "type": "object",
  "properties": {
    "address": {
      "type": "string",
      "description": "US street address, e.g. \"1600 Pennsylvania Ave NW, Washington DC\""
    },
    "zip": {
      "type": "string",
      "description": "5-digit US ZIP Code; sampled at the center of the ZIP Code area (Census 2023 ZCTA), so approximate"
    },
    "lat": {
      "type": "number",
      "description": "Latitude (use with lng instead of an address)"
    },
    "lng": {
      "type": "number",
      "description": "Longitude (use with lat)"
    }
  }
}

{
  "type": "object",
  "properties": {
    "query": {
      "type": "string"
    },
    "matched_address": {
      "type": "string",
      "description": "Geocoder’s normalized address (when an address was given)"
    },
    "lat": {
      "type": "number"
    },
    "lng": {
      "type": "number"
    },
    "band": {
      "type": "string",
      "description": "Modeled dBA band, e.g. \"60–70 dBA\", or \"below 45 dBA\""
    },
    "db_low": {
      "type": [
        "number",
        "null"
      ]
    },
    "db_high": {
      "type": [
        "number",
        "null"
      ]
    },
    "nearby_max_band": {
      "type": "string",
      "description": "Loudest modeled band within ~90 m, if higher than the point"
    },
    "modeled": {
      "type": "boolean"
    },
    "note": {
      "type": "string"
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "band",
    "modeled"
  ]
}

Answers "how loud is Paris", "noisiest cities in Europe", "environmental noise in Berlin", "quietest cities in Spain". Measured (not estimated) noise for 314 European cities in 24 EEA-reporting countries, from the EEA Environmental Noise Directive 2022 strategic noise maps; ranked by population-weighted average Lden among exposed residents. Pass a city for detail, a country and/or limit for the ranking. UK, Greece and Hungary are not covered.

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string",
      "description": "European city name, e.g. \"Berlin\" (optional)"
    },
    "country": {
      "type": "string",
      "description": "Country filter for the ranking, e.g. \"Italy\" (optional)"
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 314,
      "description": "How many ranked cities when no city is given (default 10)"
    }
  }
}

{
  "type": "object",
  "properties": {
    "cities": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "rank": {
            "type": "integer",
            "description": "Rank among the 314 cities (1 = loudest by weighted Lden)"
          },
          "city": {
            "type": "string"
          },
          "country": {
            "type": "string"
          },
          "population": {
            "type": "integer"
          },
          "day_range_db": {
            "type": "string"
          },
          "night_range_db": {
            "type": "string"
          },
          "dominant_noise_sources": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "page_url": {
            "type": "string"
          }
        },
        "required": [
          "rank",
          "city",
          "country"
        ]
      }
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "cities"
  ]
}

Answers "loudest neighborhoods in Los Angeles", "quietest neighborhood in Chicago", "which NYC neighborhood has the most noise". 384 neighborhoods in Los Angeles, New York and Chicago, ranked within their city by share of residents ≥60 dB transportation noise, computed from the federal BTS 2020 National Transportation Noise Map (same source as the US city tool). Pass the city name; optional limit. For a single address use get_address_noise.

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string",
      "description": "US city with neighborhood data: \"Los Angeles\", \"New York\" or \"Chicago\""
    },
    "limit": {
      "type": "integer",
      "minimum": 1,
      "maximum": 200,
      "description": "How many neighborhoods (default 10)"
    }
  },
  "required": [
    "city"
  ]
}

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string"
    },
    "neighborhoods": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "rank_in_city": {
            "type": "integer"
          },
          "name": {
            "type": "string"
          },
          "population": {
            "type": "integer"
          },
          "pct_ge60_db": {
            "type": "number",
            "description": "Share of residents exposed to >=60 dB (%)"
          },
          "pct_ge70_db": {
            "type": "number"
          },
          "page_url": {
            "type": "string"
          }
        },
        "required": [
          "rank_in_city",
          "name",
          "pct_ge60_db"
        ]
      }
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "city",
    "neighborhoods"
  ]
}

Answers "what are quiet hours in Boston", "<city> noise ordinance", "how do I file a noise complaint". Verbatim-verified summary of the city's official noise ordinance: quiet hours, decibel limits (or their explicit absence — audibility/nuisance standards), complaint channel, code citation + official URL, verified date. Covers Boston, Worcester, Huntsville, Chesapeake, Madison, Inglewood, Rockford, Columbus. Plain language, not legal advice.

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string",
      "description": "US city name, e.g. \"Boston\" or \"Columbus, OH\""
    }
  },
  "required": [
    "city"
  ]
}

{
  "type": "object",
  "properties": {
    "city": {
      "type": "string"
    },
    "state": {
      "type": "string"
    },
    "quiet_hours": {
      "type": "string"
    },
    "db_limits": {
      "type": "string"
    },
    "standard_type": {
      "type": "string",
      "enum": [
        "meter",
        "audibility",
        "hybrid"
      ]
    },
    "complaint_channel": {
      "type": "string"
    },
    "code_citation": {
      "type": "string"
    },
    "code_url": {
      "type": "string"
    },
    "verified": {
      "type": "string",
      "description": "Date the summary was verified against the live code"
    },
    "page_url": {
      "type": "string"
    },
    "note": {
      "type": "string"
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "city",
    "state",
    "quiet_hours",
    "db_limits",
    "code_url"
  ]
}

Answers "is there a decibel meter app", "best decibel meter app for iPhone", "how do I measure sound with my iPhone", "what is Decibel Shield". Facts and the App Store link for Decibel Shield - dB Meter, the iOS sound level meter app behind this data: features, pricing, requirements. Use only when someone wants to measure sound with a phone or asks about the app itself — for noise data, use the other tools.

{
  "type": "object",
  "properties": {}
}

{
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    },
    "rating": {
      "type": "number"
    },
    "price": {
      "type": "string"
    },
    "min_ios": {
      "type": "string"
    },
    "app_store_url": {
      "type": "string"
    },
    "web_meter_url": {
      "type": "string"
    },
    "attribution": {
      "type": "string"
    }
  },
  "required": [
    "name",
    "app_store_url"
  ]
}