By Dr Laila Abdel Aal Alghalban
It is always late when we recognise that very precious things we use to take for granted have gone or about to go forever. Only then do we realise that we were very lucky to have such gifts, and we should have been more grateful to our Creator, the Giver of all blessings. Only then do we know that we have to be ready to fight a hard battle as time or aging clips our cognitive wings and drains our resources.
As we grow older, so does our struggling with proper and convenient speech perception. We wrestle with catching up an increasing amount of speech signals that come to us like a tried, waning person reaching destination after the end of a long, difficult ride.
‘My world shrank due to delayed hearing treatment,’ reads a headline in the BBC this week, quoting a woman wrestling with hearing problems and regretting seeking early medical help. The clause ‘My world shrank’ has shocked me, it epitomises the feeling of imprisonment, loneliness, frustration, confusion and loss we may experience, when we end up losing contact with the outside world and suffering from ‘ sensory deprivation’, when we stop hearing clearly the singing of birds, the whispering of winds , the rustling of dry leaves , and the gurgling of water streams, and when we miss the brain relaxation, depression and anxiety management, and nature connection these sounds grant us. Everyday talk turns into puzzles, every time we have to fill the gaps of missing sounds and words, usually shrouded in muffled speech clouds and buzzing background noise. When we grow older, we nod, smile and pretend that we hear well, just to avoid asking for repetition. Embarrassed by repeating “Sorry, I didn’t catch it,” we try to save the day by guessing the missing words or sounds, thanks to memory, context and lip reading.
Sounds, have mercy on us
Recent research shows that aging affects brain activities during hearing. In one study, it has been found that in noisy environments, young adults are sensitive to loud music or talk and overlook the soft sounds or noise in the background, unlike the older adults who are sensitive to soft sounds as well, and cannot filter out background noise. The damage of the hair cells in the cochlea in the inner ears, probably due to genetics, aging or exposure to much noise, is irreversible, and results in our losing the ability to perceive high-pitched sounds, whistles, sirens or alarms. Sometimes, we wished we would have the auditory fields of elephants, dolphins, dogs or lions to be able to hear sounds from miles away and live in harmony with ecosystems. Of course, having similar auditory fields would cause overwhelming sensory overload, unbearable psychological stress, and unending noise that would turn life into hell!
A compensatory mechanism
Guessing missing sounds and words is a compensatory mechanism that entails a cognitive burden. As mentioned previously, when we grow older, we lose the ability to sift the important sound signals in noisy environments; all incoming sound signals are processed with equal cognitive efforts, which mandates extra attention to auditory stimuli. Moreover, the speed of the nerves in the inner ear responsible for sending the magnetic resonances of the incoming sound waves to the brain to perceive them as sounds decreases by time, which leads to slower neural processing and speech intelligibility.
Vowels vs. consonants
Usually, when we hear an incoming sound signal, our ears catch the most sonorous sounds, often a vowel or a distinctive consonant essential to shaping the word or utterance make-up.
The most unaffected sounds by hearing impairments in older adults are the vowel sounds. Vowels are inherently more sonorous (louder) than consonants; they are heard more clearly, focused around low frequencies and have longer wavelengths that can travel far. Conversely, consonants are less sonorous, generally focused around higher frequencies (being mere noise in case a consonant is voiceless i.e.pronounced without the vibration of the vocal folds such as f, s, and k) and have shorter wavelengths that cannot travel far away because they are ‘easily absorbed.’ Hearing loss often affects the ability to hear high-frequency sounds more severely than low-frequency sounds. We rely chiefly on vowels to perceive speech; they represent the backbone of the overall phonetic structure of words, tempo, rhythm and the primary resource in speech perception. The role of consonants is considerably significant. Guessing the consonant sounds at the beginning or end of words is a tough task. Consonants are abrupt sounds; they are less sustained than vowels.
The brain loses ability to detect the critical features of the consonants, a matter that causes auditory fog. Consequently, guessing does not work in many cases, which causes a lot of frustration and disappointment. The brain loses detecting consonants in hearing, despite their lower sonority and intensity because consonants are high-frequency sounds. High-frequency sounds in speech are those with frequencies above 2000 Hz, primarily consisting of certain consonant sounds like f, s, and th. These sounds are crucial for the clarity and intelligibility of speech; consonants help listeners distinguish words, even though the lower-frequency vowel sounds are louder.
Let us grasp the nettle!
It was surprising to know that ears of older adults does not catch high-pitched consonants like k, s, and f. Finally, let us get real. Acknowledging the overwhelming impact of hearing weakness as older adults is the key. Now, it is time to tackle it and find a way out. For people who start undergoing this worrying experience, you are not alone. Humans are amazing species; we have an instinctive will and ability to fight , to be resilient, and to adapt. Let us grasp the nettle! .
By Dr Laila Abdel Aal Alghalban Professor of linguistics Faculty of Arts Kafr el-sheikh University
Email: [email protected]
