Ram Chodnovsky, an acoustics specialist, performs a test: He stands in the middle of a restaurant, talks and begins to back away, taking large steps as he speaks. In the best case, after two or three steps back the desired goal is achieved - it is impossible to understand what he is saying. Thanks to a number of acoustic aids, the murmur becomes "white noise."

Regrettably, this doesn't happen at many restaurants. According to Chodnovsky, in some restaurants in Israel, including some elite restaurants, reasonable acoustics is merely a recommendation - which does not accord with the desires of the architect and the owner. The word of a architect or a designer is more important than that of an acoustics specialist.

"In most cases the result is a cacophony," says Chodnovsky, "noise over the permitted decibel level and just as bad as that: the possibility of hearing and understanding every world of the conversations going on at adjacent tables."

If we add to this the basic Israeli lack of politeness, the shriek of the mobile telephone and Israelis' typical nosiness - it is clear why it is hard to go out for an intimate meal at a restaurant. It is, of course, possible to talk at restaurants, but preferably not about very private matters. And if you want to close an important deal or discuss an appointment to a position, it is best to do so in an isolated corner.

Chodnovsky is an acoustic consultant to restaurants, event spaces and bars (including being responsible for the peripheral soundproofing at the "Big Brother" house ). He specializes in stopping noises, silencing, neutralizing typical sounds such as what is unknown as "silverware noise" in the experts' jargon, and adjusting music volumes for bars and clubs.

The measure most important to him is what he calls "the level of conversation understandability."

An acoustic tour with Chodnovsky at leading restaurants in Israel is an unusual experience, including the ritual of walking backwards and speaking more loudly (before the amazed eyes and ears of the diners ) and a minute examination of curtains, carpets, ceilings and wooden floors. At one restaurant Chodnovsky fell in love with the ceiling.

Blushing ceiling

Despite its modest, seemingly office-like appearance this ceiling won compliments that could have caused it to blush.

At another veteran restaurant there were many compliments of an excellent audio system, which made up for acoustic defects. Acoustic advantages achieved by chance were also diagnosed: old buildings that have been reconstructed where the original design was acoustically intelligent.

According to Chodnovsky, modern design - that which sanctifies concrete and glass - presents many challenges to experts in acoustics. "The more the materials are of the sort that bounce back the energy, rigid, hard and smooth, the higher the volume of the noise. It must not be forgotten that Mozart and Beethoven played their music in rooms that did not require an acoustics expert - with thick carpets, a high ceiling and curtains," he says. "It is necessary to have fibrous materials to swallow noise: The air that passes though fibrous materials causes friction, the loss of energy that we are looking for."

In order to create good acoustics, it is necessary to have a porous, preferably insulated ceiling, curtains or carpets, a wooden floor and spaces that are divided up to provide conversation corners.

Then there are good psycho-acoustics. In museums, for example, the echo level is very high and everyone speaks in whispers so as not to be heard.

Over time this is a disturbing phenomenon. "When you're sitting in a restaurant you want to be able to converse freely," he notes.

The first stop on the restaurant tour is Pasha, a Turkish restaurant on Haarba'a Street in Tel Aviv. According to Chodnovsky, the investment in the area of acoustics there is evident: The ceiling is porous and twists like a maze, the walls are made of reinforced concrete (which prevents the diners along the western wall from hearing noise from the adjacent bar Punch Line ) and the restaurant is partitioned by screens, which help diffuse the noise. And of equal importance: There is moderate spillover from the open kitchen, which creates a not very noisy buzz.

"The noise from the kitchen is comparable to bowling balls rolling from the cooking area to the seating areas, and not all of them managing to maintain their momentum and hit the target," says Chodnovsky. "This is exactly the degree of noise needed for a restaurant."

Chodnovsky performs an experiment: We are sitting at the bar and he is talking loudly to the barmaid without the help of hand gesticulations - she does not hear him. Despite the problematic situation, Chodnovsky is pleased. "This is the force of decibels desirable for voices," he says.

At the Unami Japanese restaurant we encounter a hard floor, concrete walls and large glass windows. Most of the diners are talking in a reasonable tone and not raising their voices. The decibel level is normal, but Chodnovsky is not happy with it. He locates an acoustically sane corner at the edge of the restaurant, in an area close to cloth curtains. In the rest of the restaurant, in his opinion the acoustics are mediocre.

Fortunately, a fine audio system is installed there. It is possible to listen with pleasure to the Alan Parsons Project album "Eye in the Sky." And to hold a conversation? That's a different story - unless you are interested in the whole restaurant hearing everything you have to say. The restaurant management is aware of the situation. "When the restaurant is lively there's an acoustics problem," says Avishai Birenbaum, the restaurant manager. "The sound in the afternoon is quieter, but in the evening it's noisy. The acoustics here aren't the best in the city, but we are living with it. There was an acoustics consultant here, and this is the result. We haven't ignored the issue."

Further along Haarba'a Street we find an example of a small bistro, laden with modern materials, where the acoustics are dreadful: the healthful, designer Biala restaurant. The floor is concrete, the ceiling is smooth and the walls are glass. The restaurant is not entirely full at the time of the inspection but the voices of the diners are quite loud. According to Chodnovsky, it is possible to understand everything that is being said at every table, and even at high volume; the glass produces an amplification effect.

In response, owner Ron Biala says: "Indeed, we did not have the help of an acoustics consultant and I admit the acoustics aren't good. However, the place is urban, where the clients sit for a short time and they are used to the noise of the city. In our next restaurants we will hire an acoustics consultant because this bothers us, especially in the evening hours, when the place changes its character."

Around the corner we chalked up a surprise at Tamara, a small, veteran bistro on Hashmonaim Street. We walked past it during the course of our wanderings and something about it caught Chodnovsky's eye: an old-fashioned, simple acoustic ceiling backed with rock wool. Mesmerized, he penetrated the small space, stood in the middle of the restaurant and listened with evident delight. "You see? A pleasure," he said with emotion. "With great simplicity it is possible to achieve excellent results."

In Tamara the noise is indeed barely felt, the conversation is a subdued murmur and they have succeeded in achieving considerable separation between the restaurant and the street noise. When the door closes the street seems to disappear.

Intentional noise

The consultant is very familiar with The Brasserie in Tel Aviv. There, he says, they have entirely given up on acoustic improvements. "This is simply a noisy place," he says. The tumult is huge, the music is at high volume and the tables are close to one another. Even the owner, Ruthie Brodo, admits she gave up on acoustics from the outset. "It's possible to accuse our restaurant of an acoustics problem," she says. "These aren't the quietest places - that's the intention. Hear we hear loud music. Quiet isn't a value. It could be said that Mati (her partner in the restaurant ) really hates quiet. We brought a designer surface for the ceiling from New York. I don't know to what extent this helps, but at least it looks good. An acoustics expert advised us to cover the ceiling with sponge. We said, 'No, thank you.' We love our restaurants designed according to our taste, and not the quietest."

As compared to The Brasserie, there are restaurants in Tel Aviv where great importance is attributed to acoustics. For example, Raphael, where businesspeople, politicians and diplomats meet for business lunches and dinner, and where the dimension of "conversation understandability" is very important. Presumably, the diners would not want to share their conversations with the rest of the people there.

Another restaurants considered to be a business focal point and where the hosts make a point of the seating arrangements to prevent information from trickling among the tables is Chloelys in Ramat Gan. The floor in the restaurant is made of of ipe, wooden planks used for yachts and considered especially durable and thick. The restaurant is covered in curtains and the space is divided into bays and a separate private room. The acoustics at Chloelys get a good grade.

Two more restaurants that win very reasonable grades from the consultant, not in fact intentionally but thanks to their basic givens, are Reviva and Celia in Ramat Hasharon and Catit in Tel Aviv. Both establishments were opened in old buildings that were renovated for the restaurants. They excel in a good division of the space, high ceilings, a kitchen separated from the dining area and the appropriate background noises - of clinking silverware. At Catit the ceiling has also been covered in sound-absorbing material, which improves the situation.

The new Shakuf restaurant in Jaffa was also inspected, and it has obvious advantages: a double space that is not too large and has a high ceiling. In addition, all the walls are covered in thick wood panels. About 30 diners sit around the bar shaped like three sides of a square. Despite the seating arrangement, it is barely possible to eavesdrop on the conversations of the people sitting near you. Even the kitchen creates silence - it is open to the clientele but distanced from the bar. The music swallows up the cooking noises. It is clear that attention has been given to acoustics here.

Summing up the tour, Chodnovsky says, "In restaurants where 'important' conversations are supposed to take place, like Raphael and Chloelys, they have invested in acoustic aids. Catit and Reviva and Celia have a built-in advantage and at Shakuf the attention to the acoustics relates to the design."

In other words, if you aren't politicians or diplomats, go to a restaurant in order to eat and not in order to talk. Keep your private conversations for the living room.