Understanding hearing loss

Hearing loss is one of the most common sensory impairments worldwide and affects people of all ages. From mild hearing difficulties to complete deafness, the various forms and degrees of hearing loss are wide-ranging. Here you will find clear explanations of the different types of hearing loss, their causes, symptoms and treatment options, to provide those affected and their families with the information they need to make informed decisions.

What is hearing loss and why is understanding so important

Hearing loss refers to a reduction in hearing ability that can affect both the perception of volume and the clarity of sounds and speech. Contrary to popular belief, it does not exclusively refer to complete deafness, but rather to a broad spectrum of hearing impairments. These can be temporary or permanent and affect one or both ears. Understanding hearing loss goes far beyond simply knowing it exists. It involves awareness of the various causes, symptoms and effects on daily life. A sound understanding enables those affected and those around them to respond appropriately and choose the best possible treatment. It is particularly important to recognise that hearing and understanding are two distinct processes. Whilst the ear picks up and transmits sound waves, the actual interpretation and understanding take place in the brain. In the case of hearing loss, the brain has to work with incomplete information, which requires additional effort and makes understanding more difficult.

Anatomy of Hearing, How Our Hearing Works

To understand hearing loss, a basic understanding of the anatomy and function of the ear is required. The ear consists of three main parts, all of which play an important role in the hearing process. The outer ear collects sound waves and directs them through the ear canal to the eardrum. The middle ear amplifies the sound waves with the help of the three ossicles - the malleus, incus and stapes - and transmits them to the inner ear. In the inner ear, more specifically in the cochlea, the mechanical vibrations are converted by specialised hair cells into electrical signals, which are transmitted to the brain via the auditory nerve. The actual processing, evaluation and interpretation of the auditory information then takes place in the brain. This complex process enables us not only to perceive sounds, but also to recognise their meaning and distinguish between different sound sources.

The different types of hearing loss

Conductive hearing loss

Conductive hearing loss occurs when sound waves cannot be efficiently transmitted from the outer or middle ear to the inner ear. This form of hearing loss is often temporary and, in many cases, treatable or even curable. Those affected often describe the sensation of ‘hearing through a layer of cotton wool’. Speech sounds muffled and is particularly difficult to understand against a background of noise. In addition, earache or discharge from the ear may occur. The most common causes include blockages caused by earwax, fluid build-up in the middle ear following infections, damage to the eardrum or the ossicles, chronic middle ear infections, and congenital malformations. Benign tumours can also cause conductive hearing loss. Treatment depends on the specific cause and can range from simple removal of earwax to medication and surgical procedures. Hearing aids or bone conduction hearing solutions can also be used successfully.

Sensorineural hearing loss

Sensorineural hearing loss is the most common form of age-related hearing loss and is caused by damage to the inner ear or the auditory nerve. Unlike conductive hearing loss, this form is usually permanent. A characteristic feature of this type of hearing loss is that sounds are not only perceived as quieter, but are also more difficult to understand. Those affected find it particularly difficult to follow conversations in noisy environments. Ringing in the ears, such as tinnitus, often occurs as well. The main causes are natural ageing processes, in which the sensitive hair cells in the inner ear gradually die off, as well as noise-induced damage resulting from occupational or leisure-related exposure to noise. Other causes may include genetic factors, head injuries, Meniere’s disease, side effects of certain medications, or infections. A specific form is high-frequency hearing loss, which primarily affects very high frequencies. Those affected find it difficult to hear birdsong, children’s voices or consonants such as ‘s’, ‘f’ and ‘t’. Treatment mainly involves hearing aids, which are individually fitted to the patient’s hearing ability. In cases of severe hearing loss, cochlear implants may be an alternative.

Combined hearing loss

Combined hearing loss involves problems with both sound conduction and sound perception. This complex form of hearing loss poses particular challenges for treatment, as both aspects of the hearing process are impaired. The causes correspond to a combination of the factors underlying conductive and sensorineural hearing loss. Treatment may include medication, surgery or hearing aids, though a combination of different approaches is often required.

Auditory nerve hearing loss

In rare cases, hearing loss may result from damage to or the absence of the auditory nerve. With this form of auditory neuropathy, conventional hearing aids or cochlear implants cannot help, as the nerve is unable to transmit sound information to the brain. In some cases, a brainstem implant may offer a solution.

Degrees of hearing loss

The degree of hearing loss is measured in decibels of hearing loss (dB HL) and is crucial for choosing the right treatment. It is classified into different levels: With normal hearing, the hearing threshold is 25 dB HL or less. Sounds such as a softly rustling leaf or normal conversation are clearly understood. Mild hearing loss (26 - 40 dB HL) is particularly noticeable with soft sounds and high-frequency speech sounds. Consonants at the end of words are difficult to perceive, especially in noisy environments. With moderate hearing loss (41 - 55 dB HL), normal speech becomes difficult to understand, and the ringing of the telephone may go unnoticed. Conversations in groups become increasingly tiring. Moderate to severe hearing loss (56 - 70 dB HL) means that normal conversations are difficult to understand even in quiet situations. Without hearing aids, those affected experience considerable difficulty in most situations. With severe hearing loss (71 - 90 dB HL), only very loud sounds such as sirens can be heard. Music and traffic sounds seem very muffled. Hearing loss bordering on deafness or profound hearing loss (91 dB HL and above) means that speech can no longer be heard and only very loud noises, often perceived merely as vibrations, are detectable.

Causes of hearing loss in detail

Age-related changes

Natural ageing, medically known as presbycusis, is the most common cause of hearing loss. With increasing age, the sensitive hair cells in the inner ear become damaged, particularly those responsible for perceiving high-pitched sounds. This process can begin as early as the age of 40 and initially affects the high frequencies most of all.

Noise-induced damage

Noise is one of the most preventable causes of hearing loss. Both prolonged exposure to noise from loud workplaces, music or leisure activities, and one-off episodes of extreme noise can damage or destroy the hair cells in the inner ear. This damage is usually irreversible and leads to permanent hearing loss.

Genetic and congenital factors

Hereditary predispositions play an important role in the development of hearing loss. Genetic factors can cause both congenital hearing loss and an increased susceptibility to hearing loss later in life. Congenital malformations such as microtia or atresia, as well as genetic syndromes, can also lead to hearing impairments.

Diseases and infections

Various medical conditions can impair hearing. Chronic middle ear infections, Meniere’s disease, meningitis or cholesteatoma are just a few examples. Otosclerosis, a hardening of the ossicles, can also lead to significant hearing problems.

Medication-related causes

Certain medications, known as ototoxic substances, can damage the inner ear and lead to permanent hearing loss. These include certain antibiotics, loop diuretics and some cancer drugs. They should therefore always be used under medical supervision.

Recognising symptoms and early signs

The symptoms of hearing loss often develop gradually and are initially overlooked or misinterpreted. Typical early signs include difficulty understanding soft sounds, high-pitched voices such as those of women or children, or specific consonants. Many people affected feel that others are speaking unclearly or mumbling. In group conversations or noisy environments, it becomes increasingly difficult to follow conversations. Frequently asking “Pardon?” or the need to turn up the volume on the television and radio are further warning signs. Accompanying symptoms may include tinnitus, earache, discharge from the ear, dizziness or balance problems. Paradoxically, people with hearing loss can also become sensitive to noise, as the natural dampening effect of the outer hair cells is missing. An important concept for understanding the effects is the ‘speech banana’ on the audiogram. It shows which letters and sounds may be affected by hearing loss depending on volume and pitch, and helps to understand what information the brain is missing.

Diagnosis of hearing loss

If hearing loss is suspected, an ear, nose and throat specialist or hearing aid specialist should be consulted promptly. Experts recommend regular hearing tests, ideally once a year, even for young people without obvious hearing problems. The diagnosis begins with a detailed medical history, during which the patient’s background, symptoms, duration of the hearing loss and possible risk factors such as noise exposure are recorded. This is followed by a physical examination using otoscopy to check the ear canal and eardrum for inflammation, earwax blockages or other problems. The actual hearing tests involve various procedures. Pure-tone audiometry measures the hearing threshold for sounds of different frequencies and volumes. Speech audiometry assesses speech comprehension by playing back words or sentences at different volumes. Tympanometry examines the mobility of the eardrum and the ossicles to assess middle ear function. Objective tests can measure the activity of sensory cells in the inner ear or the brain to assess hearing function independently of the patient’s cooperation. The results are presented graphically in an audiogram, which shows the type and severity of the hearing loss. In certain cases, imaging techniques such as CT or MRI may be necessary to rule out structural abnormalities or fluid build-up and to identify the exact cause.

Consequences of untreated hearing loss

The effects of untreated hearing loss go far beyond mere hearing impairment and can drastically alter the lives of those affected. Social isolation is one of the most serious consequences. People with untreated hearing loss increasingly avoid social situations in which they have difficulty understanding. This leads to loneliness, withdrawal and a loss of zest for life. Communicating with family and friends becomes a burden. Scientific studies show a clear link between untreated hearing loss and dementia. The risk of age-related depression and cognitive impairment increases significantly, as the brain receives fewer auditory stimuli and may consequently lose important abilities. The constant effort to understand becomes an enormous strain and a source of stress. This can lead to headaches, muscle pain and high blood pressure. The constant focus on hearing and understanding is mentally and physically exhausting. Particularly problematic is what is known as ‘auditory dishabituation’. The longer hearing loss remains untreated, the more the brain forgets how to recognise and fill in missing speech sounds. This deprivation effect leads to a further decline in speech comprehension and is difficult to reverse later on. Safety risks arise from failing to perceive important warning signals in road traffic or in emergency situations. This can significantly increase the risk of accidents and falls. In children, undiagnosed or untreated hearing loss can severely disrupt speech development and lead to concentration problems, a decline in academic performance and a lack of self-confidence.

Modern treatment options

Hearing aids as the first choice

Modern hearing aids are high-tech devices that can do far more than simply amplify sound. They amplify sound waves that are too quiet, attenuate those that are too loud, and optimally direct them to the inner ear to compensate for individual hearing loss. They are precisely tailored to the wearer’s specific hearing ability. Today’s hearing aids offer numerous smart features such as directional microphones, noise-cancelling algorithms, hands-free functions and smartphone connectivity. They are discreet, comfortable and the negative image associated with earlier generations is largely a thing of the past. Early and regular use of hearing aids is particularly important. The brain must relearn how to understand and process sounds. The earlier a hearing aid is used - ideally from the age of 55 - 65 - the easier it is to get used to and the more lasting the success. An ENT specialist can prescribe hearing aids, which makes a health insurance subsidy possible. Detailed consultation and individual fitting are carried out by a hearing care professional.

Hearing implants for severe cases

Cochlear implants are suitable for people with severe to profound hearing loss, where conventional hearing aids do not provide sufficient improvement. They send electrical impulses directly to the auditory nerve, which the brain interprets as sounds. In children, early diagnosis enables the provision of hearing aids from as early as three months of age, which is crucial for normal speech development. Other implant solutions include hybrid implants for certain forms of high-frequency hearing loss, bone conduction hearing solutions for conductive and mixed hearing loss, and brainstem implants in rare cases of auditory nerve damage.

Medication and surgical treatments

In certain cases, medication or surgery can lead to improvement or even a cure. The removal of earwax blockages, the treatment of middle ear infections, or surgical procedures such as stapedectomy for otosclerosis can restore hearing. Sudden hearing loss can sometimes be successfully treated with corticosteroids if treatment is started promptly.

Preventive measures and hearing protection

The most important measure for preventing hearing loss is consistently protecting the ears from harmful noise exposure. This applies both in the workplace around loud machinery and in private life at concerts, whilst doing DIY, or when listening to loud music through headphones. Regular hearing check-ups through professional hearing tests can help to detect early-stage hearing loss and take appropriate action. Ototoxic medications should be avoided where possible and in consultation with the treating doctor.

Special considerations for different age groups

Hearing loss in children

For children, the so-called 1-3-6 National EHDI targets are of crucial importance: hearing screening before the age of one month, diagnosis before the age of three months and the start of intervention before the age of six months. Early treatment is absolutely crucial for normal language development, academic performance and children’s self-confidence. Specialist paediatric audiologists can provide comprehensive advice and support. Untreated hearing loss in childhood can lead to permanent developmental disorders that are difficult to compensate for later on.

Dealing with hearing loss in the family

It is important that family members also learn to cope with a family member’s hearing loss. Supportive communication strategies, patience and understanding can make everyday life considerably easier. Hearing loss within the family affects everyone involved and often requires an adjustment to usual communication patterns.

Supportive aids and technologies

In addition to hearing aids and implants, various technical aids can make daily life easier. Special headphones for watching television, light signal systems for doorbells or telephones, vibrating alarm clocks and sound amplification systems in public buildings can improve participation in social life. Communication strategies such as lip-reading and sign language offer additional ways of communicating. Self-help groups and advice centres facilitate the sharing of experiences and offer mutual support for those affected and their families.

Quality of life despite hearing loss

An active and fulfilling life is still possible even with hearing loss. Modern medical technology and a wide range of treatment options now offer almost everyone with hearing loss the chance to communicate effectively again and participate actively in life. It is crucial not to hesitate and to seek professional help at the first signs of hearing problems. The consequences of untreated hearing loss, particularly social isolation and a decline in speech comprehension, can be severe. Consulting an expert sooner rather than later can make a decisive difference to quality of life in the long term. Accepting one’s own hearing impairment and actively seeking solutions are the first steps towards better hearing and understanding. With the right support and modern aids, hearing loss need not mean the end of active participation in life.