Hearing loss is a major public health problem because it affects communication, social participation, occupational functioning, and overall quality of life. Global estimates show that hearing impairment contributes substantially to years lived with disability, with the burden increasing as populations age [1,2]. The Lancet Commission and global hearing health literature have emphasised that adult hearing loss requires greater clinical and public health attention because many affected persons remain undiagnosed or untreated despite the availability of effective diagnostic and rehabilitative options [1,3].

Adult hearing loss is not a single clinicopathological entity. It includes sensorineural, conductive, and mixed patterns, each with distinct mechanisms, clinical correlates, and management pathways. Sensorineural hearing loss is frequently linked to ageing, cochlear degeneration, vascular compromise, metabolic disease, and chronic noise exposure. Age-related hearing loss, or presbycusis, is typically bilateral, progressive, and more prominent at higher frequencies [4,5]. Conductive hearing loss, in contrast, often reflects external or middle-ear pathology such as wax impaction, tympanic membrane perforation, otitis media, ossicular dysfunction, or eustachian tube dysfunction [6].

Several risk factors influence the onset and severity of hearing loss in adults. Population-based data have shown associations with older age, male sex, lower socioeconomic status, occupational noise, smoking, cardiovascular risk factors, and diabetes mellitus [7,8]. Smoking has been linked to a higher likelihood of hearing impairment, possibly through vascular and oxidative pathways [9]. Diabetes mellitus and hypertension can contribute to cochlear microangiopathy, neural dysfunction, and accelerated sensorineural damage [10,11]. Occupational and environmental noise exposure remains an important preventable contributor, especially in adults exposed to industrial, agricultural, traffic, or machinery-related sound without adequate protective measures [12].

Middle-ear disease continues to contribute significantly to avoidable hearing loss, particularly in resource-limited settings. Chronic otitis media and tympanic membrane perforation can produce conductive or mixed hearing loss through impaired sound transmission, middle-ear inflammation, and ossicular involvement [13,14]. In clinical ENT practice, patients often present late with overlapping symptoms such as reduced hearing, tinnitus, ear discharge, aural fullness, vertigo, or recurrent ear infection. A structured assessment of clinical presentation, risk factors, otoscopy, and audiometry is therefore necessary for accurate diagnosis and appropriate treatment planning.

The present study was conducted with the objective of evaluating the clinical spectrum, risk factors, otoscopic findings, and audiological patterns of hearing loss among adult patients attending a tertiary care ENT centre. The study also aimed to describe the distribution of hearing loss according to type, severity, audiogram pattern, and probable clinical diagnosis in this hospital-based population.

Study design and setting: This hospital-based observational study was conducted in the Department of Otorhinolaryngology at KIMS, Amalapuram, Andhra Pradesh, India. The study period extended from August 2025 to January 2026. A total of 100 adult patients presenting with hearing-related complaints during the study period were included using consecutive sampling. The study was designed to describe the clinical profile, risk factors, otoscopic findings, and audiological patterns of hearing loss in routine tertiary care ENT practice. Study population: Patients aged 18 years and above who attended the ENT outpatient department with reduced hearing, tinnitus, ear discharge, aural fullness, vertigo, or other hearing-related complaints were eligible for inclusion. Patients who were unwilling to participate, those with incomplete clinical or audiological records, and those requiring emergency management before audiological assessment were excluded. Demographic variables included age, sex, residence, and laterality of hearing loss. A structured case record form was used for uniform data collection. Clinical assessment: All patients underwent detailed history-taking with emphasis on symptom duration, laterality, associated otological symptoms, previous ear infection, ear surgery, head trauma, family history of hearing loss, ototoxic drug exposure, smoking, and occupational or environmental noise exposure. Comorbid illnesses, particularly diabetes mellitus and hypertension, were documented from history, treatment records, or available clinical notes. Otoscopic examination was performed to assess the external auditory canal, tympanic membrane status, perforation, retraction, tympanosclerosis, wax impaction, discharge, and other visible pathology. The diagnostic approach was guided by standard clinical principles used in adult hearing loss evaluation [6,7]. Audiological evaluation: Pure-tone audiometry was performed in a sound-treated environment wherever clinically feasible. Air-conduction and bone-conduction thresholds were assessed across conventional speech frequencies, and pure-tone average was calculated using standard frequencies. Hearing loss was classified as sensorineural, conductive, or mixed based on air-conduction thresholds, bone-conduction thresholds, and the presence or absence of an air-bone gap. Severity was categorised as mild, moderate, moderately severe, severe, or profound according to audiometric thresholds. Audiogram configuration was recorded as high-frequency sloping, flat, conductive air-bone gap pattern, or mixed pattern. The probable clinical diagnosis was assigned by integrating symptoms, otoscopic findings, risk factors, and audiological results. Statistical analysis: Data were entered into a spreadsheet and analysed using descriptive statistics. Continuous variables were expressed as mean with standard deviation. Categorical variables were summarised as frequency and percentage. Since the primary objective was descriptive, no inferential comparison was planned for the main analysis. Percentages were calculated using the total sample size of 100 as the denominator unless otherwise specified. Ethical considerations: The study was conducted in accordance with institutional ethical standards and the principles of the Declaration of Helsinki. Institutional Ethics Committee approval from KIMS, Amalapuram, should be inserted by the authors before journal submission. Written informed consent was obtained from all participants before enrolment. Patient confidentiality was maintained, and anonymised data were used for analysis and manuscript preparation.

A total of 100 adult patients attending the tertiary care ENT centre with hearing-related complaints were included in the study. The mean age was 48.6 ± 15.2 years. Most patients belonged to the 51-60 years age group. Males constituted 56.0% of the study population. Bilateral hearing loss was more common than unilateral hearing loss, as shown in Table 1.

Table 1. Baseline demographic and clinical characteristics of the study population

Reduced hearing was the presenting complaint in all patients. Tinnitus was the most common associated symptom, followed by ear discharge and aural fullness. Vertigo and ear pain were less frequent. More than half of the patients had symptoms for more than 6 months, indicating a predominantly chronic pattern of disease presentation (Table 2).

Table 2. Clinical presentation and symptom duration

Table 3. Risk factors and otoscopic findings among the study population

Noise exposure was the most frequent risk factor, followed by smoking and recurrent otitis media or chronic ear discharge. Diabetes mellitus and hypertension were also common comorbid conditions. On otoscopic examination, normal tympanic membrane findings were seen in 40.0% of patients, while tympanic membrane perforation was observed in 24.0%. Retracted tympanic membrane and impacted wax were also noted, as presented in Table 3.

Sensorineural hearing loss was the most common audiological pattern, observed in 52.0% of patients. Conductive hearing loss was present in 28.0%, while mixed hearing loss was noted in 20.0%. Moderate hearing loss was the most frequent severity category, followed by mild hearing loss. The commonest clinical diagnosis was age-related sensorineural hearing loss, followed by chronic otitis media-related hearing loss and noise-induced hearing loss (Table 4).

Table 4. Audiological pattern, severity, and clinical spectrum of hearing loss

Overall, sensorineural hearing loss was the leading audiological pattern among adults attending the tertiary care ENT centre. Advancing age, noise exposure, diabetes mellitus, and hypertension were common among patients with sensorineural hearing loss, whereas recurrent ear infection and tympanic membrane pathology contributed mainly to conductive and mixed hearing loss. Multiple risk factors were present in some patients.

The present observational study described the clinical spectrum, risk factors, otoscopic findings, and audiological profile of adult hearing loss in a tertiary care ENT centre. The study population had a mean age of 48.6 years, with the largest proportion in the 51-60 years age group. This age distribution is clinically relevant because hearing thresholds decline progressively with advancing age, and age-related cochlear degeneration becomes increasingly apparent from middle age onward [4,5]. The male predominance observed in this study is also consistent with population-based studies in which male sex and noise-related exposures contribute to higher rates of hearing impairment [7,8].

Bilateral hearing loss was more frequent than unilateral hearing loss, reflecting the contribution of systemic and bilateral cochlear processes such as presbycusis, diabetes mellitus, hypertension, and chronic noise exposure. Sensorineural hearing loss was the dominant audiological type, accounting for 52.0% of cases. This finding agrees with the broader understanding that age-related and noise-induced cochlear damage constitute major causes of adult hearing loss [5,12]. The high-frequency sloping audiogram pattern observed in 38.0% of patients further supports the role of cochlear pathology.

Noise exposure was the most common risk factor in the present study. Occupational noise has been repeatedly identified as a preventable cause of permanent hearing loss, and systematic review evidence confirms that workplace noise contributes substantially to adult hearing impairment [12]. Smoking was reported in 28.0% of patients. Earlier epidemiological work demonstrated a significant association between cigarette smoking and hearing loss, indicating that vascular and oxidative injury mechanisms deserve attention during risk-factor assessment [9]. Diabetes mellitus and hypertension were also common in this cohort. These comorbidities are clinically important because metabolic and vascular changes can affect cochlear perfusion and neural integrity [10,11].

Middle-ear disease formed the second major clinical pathway in this study. Ear discharge and recurrent ear infection were frequent, while tympanic membrane perforation was observed in 24.0% of patients. Chronic otitis media remains an important cause of avoidable conductive and mixed hearing loss, particularly in settings where delayed consultation and recurrent infection are common [13]. The relationship between tympanic membrane perforation characteristics and degree of hearing impairment has also been documented in chronic suppurative otitis media [14]. In the present study, conductive hearing loss accounted for 28.0% and mixed hearing loss for 20.0%, reinforcing the need for careful otoscopy and early treatment of middle-ear pathology.

Moderate hearing loss was the most common severity category, followed by mild hearing loss. This pattern indicates that many patients reached specialist care before severe disability developed, creating an opportunity for early intervention. The leading diagnoses were age-related sensorineural hearing loss, chronic otitis media-related hearing loss, and noise-induced hearing loss. These findings highlight the dual burden of degenerative cochlear disease and preventable middle-ear or noise-related pathology. A structured approach combining history, otoscopy, pure-tone audiometry, comorbidity assessment, counselling on hearing protection, and timely referral for hearing aids or surgery can reduce the functional impact of hearing loss in adults [3,6].

Limitations

This study was conducted at a single tertiary care centre with a sample size of 100 patients, limiting wider generalisation. The cross-sectional design restricted temporal interpretation between risk factors and hearing loss. Noise exposure and smoking history were based on patient reporting. Advanced investigations, speech audiometry, long-term follow-up, treatment outcomes, and quality-of-life assessment were not included in the present analysis.

In this observational study of 100 adult patients attending a tertiary care ENT centre, sensorineural hearing loss was the predominant audiological pattern, followed by conductive and mixed hearing loss. Bilateral involvement, tinnitus, chronic symptom duration, and moderate hearing impairment were common. Advancing age, noise exposure, smoking, diabetes mellitus, hypertension, recurrent ear infection, and tympanic membrane pathology were important clinical contributors. The findings support routine audiological screening in adults with otological symptoms and systemic risk factors. Early diagnosis, counselling on noise protection, control of metabolic comorbidities, treatment of middle-ear disease, and timely hearing rehabilitation can reduce disability, preserve communication, and improve quality of life in similar hospital-based adult settings across regions.

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