Less than one hundred years ago, it was thought by many that the ‘sound barrier’ was a tangible wall - and that an aircraft going faster than the speed of sound would physically crash through it, resulting in its destruction. Only when pilot Chuck Yeager exceeded this speed, in October 1947, was more understood about the phenomenon, caused by aerodynamic drag, and the explosive noise that it creates. For those who don’t know, both Yeager and his aircraft survived, and he is 97 years old as of February 13, 2020!
Very few of us will ever have the experience of flying an aircraft – much less one at such speed – in our lifetime. Nevertheless, the sound barrier is something that many of us encounter in our day to day lives; what’s more, it can be a physical entity, with implications on many other levels.
Yet sound, despite its seeming dependence on our aural function to, quite literally, ‘make itself heard,’ often transcends barriers of all kinds. This is due, in part, to our emotional response to sound. Patients in a coma have been shown to respond to the voices of loved ones, for instance. People suffering from dementia and similar diseases that impact on cognitive function have, similarly, been shown to be stimulated by well-loved sounds: a melody that was once sung to one’s child, or danced to with one’s sweetheart, for example, or a song crooned by a favourite pop idol.
Sound is not necessarily a cure for such conditions, but it is often a breakthrough of sorts; some way of sufferers and their loved ones demonstrating recognition and, consequently, connection. Even sounds that may not, on first consideration, appear emotionally-charged, may in fact be loaded with significance: the whistle of a kettle, for example, may not seem to be something that plucks at the heartstrings and tugs on emotion, but could well be invested with images of routine, comfort and familiarity – all of which have a psychological significance that goes beyond the mere drinking of a mug of tea.
A world without walls
There are other ways in which barriers, of many kinds, are no obstacle to sound. The noise from next door’s party that seeps through the walls may be one, albeit one that’s rather less positive than others! There are also cultural barriers through which sound explosively penetrates: think, for example, of the cheering (and jeering) at a football match. Despite people of all backgrounds and cultures being in attendance, everyone will understand the sounds of celebration or, alternatively, of despair. The same may be said of the global popularity of singers and pop stars, especially now that social media, Spotify and similar downloading capabilities have made music, regardless of country of origin, swiftly accessible to everyone.
Song lyrics are often complex; certainly, more complex than a non-native speaker can be expected to fully understand. Yet anguished songs of heartbreak, upbeat party anthems, tunes capturing the dizzy, heady emotions of new love - these sounds pierce barriers, both linguistic and aural. A person with impaired hearing, or a person with no knowledge of a particular language - or even both - may capture the feeling behind what they are hearing.
The universal language
Why do such sounds ‘speak’ to people, regardless of their ability to decipher language or, indeed, to hear clearly at all?
Where hearing impairment is concerned, it is largely the vibrational aspect of music that remains accessible; profoundly deaf people have been shown to enjoy music and indeed, to campaign for greater access to live gigs. Even at home, however, the thrum of instrumentals and the amplifications coming from speakers can evoke responses and provide joy. As Henry Wadsworth Longfellow is often quoted as saying: “Music is the universal language of mankind.” Hearing is one of the five senses, yes – but music – and, indeed, sound - is also a sensation in and of itself.
Studies have shown, for example, that a clip of as little as 14 seconds’ duration is enough to give listeners an accurate insight into the ‘meaning’ of a song – demonstrating that, not only is ‘music deeply rooted in human nature, but that some types of songs transcend cultural boundaries.’ Listen to even a brief snatch of song and, it has been determined, users can differentiate between lullabies, music intended to be danced to, or music to convey love. This ability to discern meaning was despite differences in background: the 750 participants in this particular study were drawn from 60 countries and the songs had been ‘collected from nearly 90 small societies around the globe, including hunter-gatherers, pastoralists and subsistence farmers.’
Hearing and meaning
That said, as much as it is the case that emotion is the tool that may crumble or penetrate the sound barrier, so too it may sometimes be the aspect of human experience that puts the barrier in place. How? Because how we hear and how we actually listen are two different, but tightly linked things. Regardless of aural function, our feelings may build a barrier between what is heard and how we hear - and how we process it. For example, feelings such as boredom, dislike and preconception may build walls that alter the impact of what is being said. By the same token, even though emotions such as love, acceptance and interest (which imply invitation and openness) may appear to be feelings that would remove, rather than build, blockades, they can still, on occasion, create a barrier of sorts by altering perception and distorting the essence of what is actually intended to be conveyed. The expression “people hear what they want to hear” refers to this phenomenon: various feelings, whether positive or negative, can result in a message being heard that is different from that which is being transmitted.
Our own minds, and the speed at which they work, may also create a ‘sound barrier’ of sorts. It is estimated that the human brain can formulate ‘inner speech’ at the rate of about 4,000 words per minute, which is about 10 times faster than verbal speech. In this way, it is believed, a listener’s thoughts may often be skipping far ahead of the speaker’s message, formulating responses, critically evaluating content and making assumptions about end-points and outcomes. All of this mental activity may create a sound barrier that precludes effective communication.
Breaking the barrier
Of course, physical, and not just emotional, factors also come into play. Think, for instance, of how hard it is to follow a conversation in a noisy environment, or when the television or radio volume is dialled to ‘high.’ For someone with reasonable hearing, such situations may be loaded with stress, anxiety and perplexity. For someone with impaired hearing, such ‘sound barriers’ may be all of this and more: impenetrable and drowning out everything other than the barest of meaningful sound waves.
How to break the sound barrier in these circumstances?
As mentioned, vibrational activity can ‘speak’ to those who cannot ‘hear’, in the conventional sense. Nevertheless, the additional – and subtle - nuances of language, syntax and tone will invariably be lost.
Hearing aids may magnify sound, but do they make it more intelligible? For some users, amplification causes blurring and crackle, which may ultimately be more stressful or disconcerting than not being able to hear at all. Imagine the sensation of looking at something through a lens that enlarges but does not focus. The viewer can see, but they cannot see what they are seeing.
When hearing difficulties are a matter of volume, such technology may be more than adequate. Yet in 1957, just 10 years after Chuck Yeager broke the sound barrier, the potential for the breaking of more terrestrial sound barriers was invented, with the first cochlear implant. Ever since the successful implantation of the first multi-channel cochlear implant in 1977 by surgeon Professor Kurt Burian at Vienna’s General Hospital, the invention of Ingeborg Hochmair-Desoyer and her team helps to restore hearing for individuals with different types of hearing loss. Unlike hearing aids, which make sounds louder, cochlear implants directly stimulate the hearing nerve and completely bypass the damaged part of the ear. According to studies, people with the implant could understand sentences – not just sound and implied meaning, but actual word choice and intended meaning – several times better than they did when equipped with a hearing aid. For a hearing-impaired person, the barrier to sound may take many forms, whether emotional, physical, or a mix of both – but the technology that exists to break through that sound barrier can be as momentous as that which was imagined by those who once visualised it as a solid and existence-altering wall.