Indoor climate and well-being
Health and safety

Breaking the Vicious Cycle of the Lombard Effect

October 9, 2023

When we increase our vocal efforts to be heard within a noisy environment, we inadvertently contribute to the existing high noise levels – making the environment noisier. Fortunately, the detrimental consequences of the Lombard Effect can be minimised.

People trying to speak at a restaurant with the Lombard Effect, Café Effect, and Cocktail Party Effect

As he examined a patient at the Hôpital Lariboisière in Paris, France, the French otolaryngologist and surgeon Étienne Lombard noticed that background noise was causing his patient to speak significantly louder.

In 1911, he published an article describing and outlining the mysterious effect: “Le signe de l'élévation de la voix” (The sign of the elevation of the voice). The phenomenon that he described would later come to be named after him: 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]


A quick search through Google Reviews or Yelp will confirm that establishments with poor restaurant soundscapes are often berated.  

Article illustration, Rockfon, blog post, insight, noisy restaurants

The Puddle Ducks Swim School in Northwich, England improved their swimming pool acoustics and minimised the risks of the Lombard Effect with the use of acoustic ceiling tiles.  

Swimming Pool in Puddle Ducks Swim School in Northwich United Kingdom Rockfon CleanSpace Pro with A-Edge

Ceiling solutions improve educational facility acoustics at the Yuverta School in Dordrecht in the Netherlands, developing an environment that is less likely to breed the Lombard Effect.  

Classroom in Yuverta, Dordrecht in Dordrecht Netherlands with Rockfon Krios A-Edge

The Lombard Effect can contribute to poor check-in procedures at hotel reception desks, tarnishing the overall guest experience.  

People in hotel reception

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 unfortunately, 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 ceiling and wall solutions. When selected and configured strategically, they can reduce reverberation and allow for improved speech clarity and intelligibility.

The selection of the right product largely depends on the space at hand and the needs. Here are the primary acoustic solutions used to minimise the Lombard Effect:

  • Acoustic ceiling tile systems: Covering a large surface area, quality acoustic ceiling tiles such as Rockfon Color-all or the monolithic Rockfon Mono Acoustic absorb sound waves and prevent them from reverberating.  
  • Acoustic islands and baffles: Solutions such as Rockfon Eclipse or Rockfon Contour are ideal for spaces where a suspended ceiling is technically or aesthetically not suitable, or where frequent and unhindered access to services is needed.  
  • Acoustic wall panels: Wall solutions such as Rockfon Canva Wall panel absorb interior sound waves while delivering statement design with their canvases, whereas the wooden modular wall system Rockfon Lamella minimises wall-based sound reverberation with an earthy touch.  
  • Acoustic dividers: With a zoning approach, dividers such as Rockfon Canva Floor screen and Rockfon Canva Hanging divider make it easy to improve acoustics in open spaces. 
  • Soft flooring and seat cushioning: When appropriate for the room type, soft materials and carpeting – especially high-pile – can help minimise impact noise, such as sliding chairs or clicking shoes.

Product features to consider when selecting acoustic solutions include desired light reflection, hygiene, fire safety, demounting frequency, impact resistance, and cleaning resistance.