“Ranchlands’ Hum”: A Calgary community noise nuisance

Modified extract from "Characterization of the “Ranchlands’ Hum”; A Calgary community noise nuisance"
presented by Mike Smith, Grimika Gupta, Emily Marasco, Marcia Epstein, Richard Patching, Ken Scott and Spoorthi Nayak
at NOISE-CON 2013, Denver, Colorado, 26-28 August 2013

Urban residents across the world are being plagued by low frequency noise of indeterminate causes.  Whether this phenomenon is caused by a single or multiple common source within the communities is still unknown, but it is collectively known as “The Hum”. Historic examples have been recorded in scientific journals and include the 1970’s Bristol Hum and the widespread Taos Hum in New Mexico.

Exposure to low frequency noise is known to cause sleeplessness, depression and vibro-acoustic disease.The stress of irritating noise can cause new health problems, or exacerbate existing conditions, including high blood pressure, coronary disease, ulcers, colitis and migraine headaches.  Noise effects are not limited to humans with chronic exposure to industrial noise from compressor stations is changing the natural pairing successes of ovenbirds in the Alberta boreal forests, as well as the distribution of songbird species populations throughout boreal areas.

In 2008, the residents in the community of Ranchlands, Calgary, Canada approached our team for assistance in locating the source of a low frequency noise nuisance which became known as “the Ranchlands Hum”.  The nuisance was described by one resident as sounding like the G-sharp note on a piano that was three octaves below Middle C, approximately 46 Hz. It could have an intensity that ranged from ‘barely audible’ during the night to ‘conversation stopping’ on different occasions. 

Given that the hum is intermittent and not experienced by many members of the community, it was important to establish the physical existence of the Hum to set aside claims and fears that it was arising from physical (tinnitus) or mental health issues.

Our long term goal is to develop a systematic approach allowing community members to (A) collect real-time audio sound signatures for comparison with (B) an established set of known “Hum” signals (gold standards) from other homes in the community or local industrial environments. This has the potential for identifying whether there is one “Ranchlands’ Hum” or many; and solve noise control complaints via fast identification of possible noise generators. This paper reports on a preliminary attempt to identify gold standard characteristics of the “Ranchlands’ Hum” using audio records from 2009 – 2011.

On this website, we provide a preliminary version of a cell phone application enabling residents to perform a real time determination of dominant room resonances for comparison with recorded local data and stored community gold standard signals.

Last updated: August 1, 2015