Breaking the Vicious Cycle of the Lombard Effect

The Lombard Effect: a vocal phenomenon

Most people frequently experience the Lombard Effect in their everyday lives.

Think of a time when you were:

• Having a conversation over dinner in a noisy restaurant

• Catching up with a colleague at a busy conference

• Checking in to a hotel property with a group

• Engaging in group activities in an educational environment

Put simply, the Lombard Effect is the involuntary tendency to speak louder to be heard and understood in a noisy environment.

Studies have identified that the Lombard Effect can already start when noise levels are above 43.3 dB(A), close to the average sound level of a refrigerator’s hum.^[2][3]

The Lombard Effect is also typically accompanied by physical efforts, namely mouth movements and the introduction of hand gestures.^[4]

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 a Zagat 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] It's no surprise quick search through Google reviews or Yelp will confirm that establishments with poor restaurant acoustics are often called out.

See also: The Ultimate Guide to Restaurant & Bar Acoustics

At sports facilities

Research indicates that average noise levels in gymnasiums are over 80 dB(A), with peak levels exceeding 100 dB(A) – which is the average noise level of an approaching subway train.^[2][10]

These high numbers are not surprising. Sports facilities are designed in a way to withstand impact such as ball play, meaning that they often require the use of hard surfaces for durability and cleanability requirements. However, such materials bounce sound waves around rather than absorb them, causing reverberation, or echoes. When music, instructors, and children come into play, the resulting levels can reach peak highs.

In sports facilities, the Lombard Effect can compromise the following:

• Staff health: Both hearing health and vocal health are at risk for physical education teachers and gymnasium staff. Research has shown that instructors who teach two or more high-intensity sessions per day might be susceptible to noise-induced hearing damage.^[11]

• Safety: The inability of children to hear instructor directions during high-energy activities can potentially lead to injury.

• Business losses: At membership sports facilities, members might choose to go elsewhere when the noise levels are too uncomfortable.

In classrooms

Whether across daycare, schools, or universities, the classroom context is one of the best examples of the Lombard Effect in action. An increase in speech amplitude is a technique most teachers resort to in order to ensure that instructions are being transferred to each student amongst the side conversations.

The vocal effect is likewise seen in students during group work, and seemingly more so in primary school children.^[12]

Consequences of the Lombard Effect in classrooms often include:

• Compromised instructor health: Both hearing health and vocal health are at jeopardy for teachers who frequently rely on the Lombard Effect. In a study with 226 teachers, about 35 percent reported an acute vocal disorder and about 25 percent reported a chronic vocal disorder.^[13] In another study, noise levels close to 87 dB(A) were recorded in classrooms – higher than the average noise levels of a leaf blower – indicating that teachers exposed to such noise levels may develop occupational hearing loss across their careers.^[2][14]

• Reduced student performance: High noise levels can disrupt everyone in the room, whether they’re trying to speak or not. Student concentration and memory can be influenced, and classroom noise levels have repeatedly been associated with test results and general academic performance.^[15]

See also: The Complete Guide to Classroom Acoustics

In reception areas

The potential for the Lombard Effect increases when occupants aggregate in a single confined space, and the reception area is no exception.

Whether at workplaces, healthcare facilities, hotels, gyms, or spas, this greeting area tends to witness high foot traffic with peak hours at certain moments throughout the day or week, such as during group check-ins into a hotel or conference, or rush hours at gyms.

Here are some of the primary consequences of the Lombard Effect in reception areas:

• Compromised privacy: Critical or personal information is often shared at reception desks, ranging from payment information to health conditions. When visitors feel forced to raise their voice in communicating a confidential piece of information, it infringes on their privacy.

• Reduced staff performance: High noise levels can impact the concentration of front desk staff and cause fatigue. In a study focused on emergency wards, noise levels ranged from 65 to 67 dB(A) – a little below the average noise levels of a dishwasher – and above the comfort levels recommended by the Association of Technical Standards in Brazil, where the study was conducted.^[2][16]

• Business losses: When the indoor environmental quality in a space is uncomfortable, people might simply choose to stop going.[8] Businesses eventually pay the price for their poor acoustics.

It’s not just visitors that contribute to the high noise levels. In many building configurations, reception areas are located at the entrance and are adjacent to the exterior. Noise pollutants such as traffic clamour can leak inwards, contributing to the high noise levels to further catapult the Lombard Effect.

Tackling the Lombard Effect

The Lombard Effect reduces the indoor environmental quality of a space and endangers its occupants.

Noise can be actively controlled with mere regulation in some contexts – the volume of ambient music can be lowered in cafes and bars, for example. But in most situations, acoustic control isn’t a mere click away. This is usually the case in locations with high occupant capacity or foot traffic such as gymnasiums and classrooms.

One way that designers and builders can take action to mitigate the notorious Lombard Effect is with the use of sound-absorbing products. When selected and configured strategically, acoustic solutions reduce reverberation to allow for improved speech clarity and intelligibility.

Here are the primary acoustic solutions used to minimise the Lombard Effect in interior spaces:

• Acoustic ceiling tiles with suspended ceiling grids

• Acoustic floating ceiling panels

• Acoustic ceiling baffles

• Acoustic wall panels & dividers

• Seamless acoustic ceilings & walls

• Soft flooring and seat cushioning

The selection of the right product largely depends on the space at hand, the needs, and a holistic strategy. Product features to consider when selecting acoustic solutions include desired light reflection, fire safety, demounting frequency, impact resistance, and cleaning resistance.

Sources:

1. ^{Bautista, Ashley. "Relationships Between Ambient Noise Levels and Vocal Effort when Working as a Restaurant Bartender." Ursidae: The Undergraduate Research Journal at the University of Northern Colorado 7, no. 2 (2019): 3.}

2. ^{Bottalico, Pasquale, Ivano Ipsaro Passione, Simone Graetzer, and EricJ. 2017. “Evaluation of the Starting Point of the Lombard Effect.” Acta Acustica United with Acustica 103 (1): 169–72. https://doi.org/10.3813/aaa.919043.}

3. ^{Bottalico, Pasquale. 2018. “Lombard Effect, Ambient Noise, and Willingness to Spend Time and Money in a Restaurant.” The Journal of the Acoustical Society of America 144 (3): EL209–14. https://doi.org/10.1121/1.5055018.}

4. ^{Bottalico, Pasquale, Rachael N. Piper, and Brianna Legner. “Lombard Effect, Intelligibility, Ambient Noise, and Willingness to Spend Time and Money in a Restaurant amongst Older Adults.” Scientific Reports 12 (1). https://doi.org/10.1038/s41598-022-10414-6.}

5. ^{“What Noises Cause Hearing Loss? .” Centers for Disease Control and Prevention. November 8, 2022. https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html.}

6. ^{Dodd, George, and James Whitlock. "Auditory and behavioural mechanism influencing speech intelligibility in primary school children." In Proceedings of the 18th International Congress on Acoustics, pp. 3581-3582. The Acoustical Society of Japan, 2004.}

7. ^{Filus, Walderes, Adriana Bender Moreira de Lacerda, and Evelyn Albizu. "Ambient noise in emergency rooms and its health hazards." International archives of otorhinolaryngology 19 (2015): 205-209.}

8. ^{Garcia Martins, Regina Helena, Elaine Lara Mendes Tavares, Arlindo C. Lima Neto, and Marisa P. Fioravanti. “Occupational Hearing Loss in Teachers: A Probable Diagnosis.” Brazilian Journal of Otorhinolaryngology 73 (2): 239–44.}

9. ^{Greier, K., C. Drenowatz, G. Ruedl, and H. Riechelmann. "Noise exposure of physical education teachers—empirical study using measurement of sound pressure level (SPL)." Health Sci. Educ 2 (2018): 1-6.}

10. ^{Herklots, Tiffany. 2018. “Zagat Releases 2018 Dining Trends Survey.” Zagat Blog. https://zagat.googleblog.com/2018/01/zagat-releases-2018-dining-trends-survey.html.}

11. ^{Sinha, Sumi, Elliott D. Kozin, Matthew R. Naunheim, Samuel R. Barber, Kevin Wong, Leanna W. Katz, Tiffany M. N. Otero, Ishmael J. M. Stefanov-Wagner, and Aaron K. Remenschneider. “Cycling Exercise Classes May Be Bad for Your (Hearing) Health.” The Laryngoscope 127 (8): 1873–77. https://doi.org/10.1002/lary.26331.}

12. ^{Trujillo, James, Asli Özyürek, Judith Holler, and Linda Drijvers. 2021. “Speakers Exhibit a Multimodal Lombard Effect in Noise.” Scientific Reports 11 (1). https://doi.org/10.1038/s41598-021-95791-0.}

13. ^{Rossi-Barbosa, Luiza Augusta Rosa, Mirna Rossi Barbosa, Renata Martins Morais, Kamilla Ferreira de Sousa, Marise Fagundes Silveira, Ana Cristina Côrtes Gama, and Antônio Prates Caldeira. "Self-reported acute and chronic voice disorders in teachers." Journal of Voice 30, no. 6 (2016): 755-e25.https://doi.org/10.1016/j.jvoice.2015.08.003}

14. ^{Shield, Bridget, and Julie Dockrell. "The Effects of classroom and environmental noise on children’s academic performance." In 9th International Congress on Noise as a Public Health Problem (ICBEN), Foxwoods, CT. 2008.}

15. ^{Whitlock, James, and George Dodd. 2006. “Classroom Acoustics - Controlling the Cafe Effect... Is the Lombard Effect the Key?” https://www.acoustics.asn.au/conference_proceedings/AASNZ2006/papers/p23.pdf.}

16. ^{Zollinger, Sue Anne, and Henrik Brumm. 2011. “The Evolution of the Lombard Effect: 100 Years of Psychoacoustic Research.” Behaviour 148 (11-13): 1173–98. https://doi.org/10.1163/000579511x605759.}