Why Following Conversations in Noisy Restaurants Can Be So Difficult

You arrive at seven and the restaurant is calm, all clinking glass and murmured orders. By half past eight the room has become a wall of sound. You lean in, nod at the right moments and laugh a beat after everyone else. On the walk home your head aches, and you could not say exactly what your friend's news was.

You are in good company. In a Norwegian survey quoted by the acoustician Jens Holger Rindel, 51% of people with impaired hearing said they often or always struggled to hold a conversation in restaurants, cafés and canteens. Including those who said "sometimes", the figure was 88%. But you do not need hearing loss to find it hard. The problem starts with the room, the crowd and the way our brains pick one voice out of many.

The problem Colin Cherry named

In 1953 the British scientist Colin Cherry published a modest-sounding paper on recognising speech "with one and with two ears". It gave psychology a lasting phrase: the cocktail party problem. How do we follow one speaker when several people are talking at once?

Cherry played listeners two different messages at the same time and asked them to repeat one aloud as it arrived, a technique later called shadowing. They managed the message they were attending to well but took in almost nothing of the other one's meaning. They did notice physical changes in it, such as a switch in the speaker's sex. The brain sorts voices using direction, pitch, timing and speaking rate, and having two working ears helps a great deal in telling where a voice is coming from.

It is a triumph of attention, but a fragile one. Every cue can be blurred by an echoing room, a dozen competing voices or an ear that has lost some of its precision.

A room that talks back

In 2017 Gregory Scott of SoundPrint, an app that lets diners log sound levels, presented crowd-sourced readings from more than 2,250 New York restaurants and bars to the Acoustical Society of America. Restaurants averaged about 78 dBA and bars about 81 dBA, levels at which comfortable conversation is not possible. The venue managers who were asked generally underestimated them. Readings logged through an app are not a controlled survey, but the pattern is hard to ignore.

Part of the reason is fashion. Open kitchens, polished concrete, glass and bare tables look convivial but absorb almost no sound, and tablecloths, carpets and soft ceilings have become rarer. Every hard surface throws speech back into the room, so other tables' voices reach you from every direction at once. That blurs the very cues Cherry's listeners relied on.

The Lombard spiral

Then the crowd joins in. In 1909 the French ear specialist Étienne Lombard noticed that people automatically speak more loudly in noise. The Lombard effect is involuntary, and we also raise our pitch and stretch our vowels to stay audible.

In a restaurant this becomes a feedback loop: one table gets louder, the background noise rises, and the next table follows. Rindel's 2019 review for the European Acoustics Association gathers decades of studies. They suggest that speech gets about half a decibel louder for every extra decibel of background noise. In his model, the noise in a room rises by about 6 dB each time the number of diners doubles.

“

Everyone in the room is shouting harder, and nobody is hearing any better.

The cruel twist is that everyone raises their voice by about the same amount, so the balance between your companion's voice and the noise around it barely improves. Rindel proposes a measure called acoustic capacity: the largest number of people a room can hold before conversation at a distance of one metre stops being good enough. On his figures, that point comes once background noise passes about 71 dB. The cure is architectural: more space per person and far more sound-absorbing material.

Why it leaves you so tired

The ache after a loud dinner has a name: listening effort. In 2016 an international group led by Kathy Pichora-Fuller published the Framework for Understanding Effortful Listening. It defines effort as the deliberate use of limited mental resources to overcome obstacles. When speech is degraded, the brain has to fill gaps, guess at missing consonants and hold half-heard phrases in memory while new ones arrive. The framework also stresses motivation. We spend that energy because we want to hear our friend, and when it stops paying off, we tend to withdraw.

Age makes the job harder. In a 2022 study in Scientific Reports, Pasquale Bottalico and colleagues at the University of Illinois Urbana-Champaign played recorded restaurant babble, complete with clinking cutlery, to 31 adults over 60, at levels from 35 to 85 dB(A). Below about 50 dB(A), they could keep their vocal effort down and understood the most, even with moderate to severe hearing loss. In quieter conditions they also said they would be more willing to spend time and money in the restaurant. Compare that with the high seventies measured in New York.

When the audiogram says you are fine

Some people find noisy rooms exhausting even though a standard hearing test says their ears are normal. One possible explanation emerged in 2009, when Sharon Kujawa and Charles Liberman at Harvard Medical School and Massachusetts Eye and Ear exposed mice to noise. The mice's hearing dipped and then fully recovered, and their hair cells survived. But many of the synapses connecting those cells to the auditory nerve were lost.

This "hidden" damage does not show up on the usual test, which measures the quietest tones you can detect, yet it would be expected to make hearing in noise harder. A 2019 study of donated human ears found a similar loss of nerve fibres with age. How much it explains for any one person is still being studied. But it fits a common complaint: being able to hear, yet not to follow.

Small mercies

Book early, before the room fills. Ask for a booth or a corner, where soft seating and walls cut down reflections, and sit with your back to the noisiest part of the room. Good light helps, because lip-reading supports the ear more than most of us realise. Some diners now check noise-rating apps before booking.

If following conversation has become steadily harder, mention it to your GP or ask for a hearing assessment. The difficulty is common and has a real physiological basis. It is not a failing of attention or manners.

✦

Filed under Hearing & Sound. Spotted an error? Tell the editors.