By increasing our vocal amplitude in order to be heard, we inadvertently contribute to existing high noise levels. Others quickly follow suit by likewise speaking louder, resulting in a vicious cycle.
Conversely, the Cocktail Party Effect refers to listeners’ selective attention in understanding speech in contexts where the Lombard Effect takes place.
But when it comes to a point that teachers need to significantly increase their vocal efforts in their classrooms – or restaurant customers and staff can’t hear what their companions and colleagues are saying – vocal health, hearing health, physical health, well-being, and business success are endangered.
The health-related consequences are multiplied for those who experience the Lombard Effect day in and day out. When vocal disorders and noise-induced hearing loss become a risk, the need for facility managers to bring in an acoustic strategy becomes urgent.
Dangers of the Lombard Effect
The Lombard Effect is often harmful to occupant well-being and comfort regardless of space type or building typology.
Here are some of the detrimental consequences the notorious vocal reflex has across various locations, including restaurants, cafes, bars, classrooms, sports facilities, and reception areas.
At Restaurants, Cafes, and Bars
The “Cafe Effect” is often used to describe spaces that tend to breed the Lombard Effect[5], primarily due to the echoes caused by their interior design. The name is appropriate: the Lombard Effect is notorious for its frequent manifestation in environments where food and drinks are served.
Here are some of the primary consequences of the Lombard Effect in restaurants, cafes, and bars:
- Compromised staff health: Both hearing and vocal health are threatened for staff that work in noisy environments. In one study, waitresses and bartenders wore multiple measurement tools throughout their shifts. Results showed that 40 percent of the participants generated vocal intensities that exceeded their comfortable vocal dynamic range – a scale identified by measuring both their low-intensity vocal production and high-intensity vocal production. Noise doses exceeded the United States’ recommended exposure limit of 85 dB(A) – or the average sound level of a gas-powered lawnmower.[2][6]
- Exclusion: High noise levels can exclude people with moderate-to-severe hearing loss such as senior restaurant customers. A study showed that participants were at approximately 50 percent correct word understanding in the lowest noise level condition. By 70 dB(A) – or the average noise level of a dishwasher – those with normal, mild, and moderate-to-severe hearing loss were almost at 0 percent intelligibility.[2][7]
- Reduced visitor count: The willingness to spend time and money in a restaurant has been proven to decrease as background noise increases. One study estimated the starting point for the financial risk to be at the noise level of 52 dB(A), slightly below the average noise level of an air conditioner.[2][8] And in Zagat’s 2018 National Dining Trends survey, noise was reported to be the most bothersome issue at restaurants – more bothersome than poor service, large crowds, high prices, and difficult parking.[9]