It is that time of year again. We will all be gathering together to celebrate. What would the party be without sound? It provides information about our surroundings. It can be as simple as someone ringing the doorbell. Someone has to go and let them in! We hear the carols being played in the background. We hear the sound of people enjoying themselves. We listen to ourselves. We can hear the food that we are enjoying in our mouths. We can hear the noise we make as we stand on the peanut or pastry we dropped.
We want to socialize and will happily clink glasses in a toast. We want to talk to people. Sometimes we can do this in a quiet corner. Other times we are in the middle of a crowded room. The noise level rises automatically. This is the Lombard effect as we speak louder and articulate more. All species, including humans, need to make themselves heard. No one can help themselves ( #019 The White Crowned Sparrow). This is made worse if the room has bad acoustics and we get a reverberation. If the party is in a typical art gallery the problems will multiply.
The Christmas Party is the most challenging environment in which to communicate. Two way communication allows us to convert a group of people into a party. At the same time we want the background noise of people laughing and even joining in with the carols. In most situations we can keep control of the sounds on which we can focus our attention. In a party that can become a losing battle. It is a problem for young and old.
A family Christmas will not be the same without one or more Grandparents. People vary in their ability to detect a single voice against a noisy background. It cannot be predicted by looking at an audiogram. This measures the thresholds at which we can detect different frequencies of sound. Those who suffer a hearing problem will often lose higher frequencies. This is due to damage in the ear from excess noise. It can worsen with age (#007 A succession of Soggy Pringles).
In general a younger person will outperform an older person. However there are plenty of exceptions. People do not have to a have a hearing aid to have a hearing problem. Our ability to process such complex auditory situations matures during our childhood. It peaks sometime in early adulthood. After that a series of factors conspire to make it more and more difficult to make sense of the situation.
In a previous newsletter I described the three key processes. We need to be able to recognize the voice of the person to whom we wish to talk. We need to know exactly from where they are speaking. We need to isolate that voice in space. Finally our brain has to trigger the “cocktail party effect”, to separate that voice from all of the background noise and voices. As we age all three processes can fail. If we lose our high frequency sounds we may not be able to recognize the voice of our target. Our spatial hearing can fail. This is thought to be because our sound thresholds rise. We need to detect the very small differences in the timing between when sound arrives at the different ears. This allows us to build the sound "picture". We seem to have more trouble marshalling the necessary cognitive capacity (#019 The White Crowned Sparrow).
Party Speaking Etiquette.
Recognizing speech is a function of the nature of the background noise. The greater the difference between the background and the speech the better. A party is one of the worst since the background noise is the same as the voice we are trying to focus on. It will pay to set our communication at the level of an older person. We can then guarantee to help everyone else who has a hearing problem.
It seems that the ”signal to noise” ratio is an issue. This is the difference between the voice and the background. Older people need a bigger signal to noise ratio. They will require a target voice to be two to four decibels louder compared to a younger person. Remember that decibels are a logarithmic scale. Three decibels means that it is about 23% louder. Experimentally a group of over 65’s was given such an increased speech volume. Most of the problems of speech separation disappeared. It appears that speaking more loudly to an older person works. It is a shame that it is also an ageist signal and may trigger the Lombard effect!
When we focus on someone we wish to talk to, it takes time for our “cocktail party” abilities to warm up. When we are younger the “system” engages almost at once. As we age it takes a while for our mind and senses to “tune in” to our fellow guest. I am not sure alcohol helps either. Give everyone time to tune in, especially an older person.
Do not forget the perceptual completion is in operation. Our perception is using all our senses to fill in the gaps (#015 Making Sense of the World) . We cannot just listen to a conversation. All of our senses engage all of the time. If you want to talk to someone turn to face them. People joke that some nationalities speak with their arms. Perhaps they have the correct idea.
Communicating at a Christmas Party is no easy task. Despite this we still have time to listen into other people’s conversations. Studies have shown that we are sensitive to hearing our own name in someone’s else’s conversation. It may not be polite but it seems to be instinctive. A study simulated a party. Two conversations were played on headphones, each through different ears. Respondents were not only asked to listen to the main conversation. They were asked to repeat the words in real time. Through the other ear was played another conversation. Their name was inserted into it. 29% of respondents noticed their own name.
The researchers were interested in whether it was only your name that could trigger the effect. They inserted incongruous words into the distraction track. They had no effect. It seems that only our own name has enough salience. They were also interested in performance of the core task. Sure enough those respondents who had registered their own name also made mistakes in the word shadowing task. It was not really possible to “multi-task”. If you are going to communicate well you will need to focus on one conversation and resist the urge to eavesdrop!
We need to speak up and face the person. We need to use our non-verbal communication skills. We need to give people time to get into the conversation. We need to concentrate on a single person and try not to be distracted. Most of all we need to enjoy the party!!