A clinical study was conducted following approval from the Institutional Ethics Committee (GAV/VAD/IEC/79/2023, dated 13/03/2023) and registered with the Clinical Trial Registry of India, ICMR, New Delhi (CTRI/2023/07/055314, registered on 18/07/2023). This was an interventional, randomized double-blind design. Criteria for selection, demographic details and history of present illness of patients were noted in designed clinical proforma (Annexure 6). A detailed description of the diagnostic criteria for Karnanada (tinnitus) was provided, along with both subjective and objective assessment criteria for evaluating outcomes. A specialized scoring system was implemented to assess results in terms of percentage relief, accompanied by statistical evaluation. The findings and results were presented in tabular and graphical format, followed by a thorough interpretation of the data and assessed the overall efficacy of the test drugs.

In this study, a total of 70 patients were screened out for assessment of eligibility criteria. But according to the inclusion and exclusion criteria, among them total 30 patients were excluded as they were meet with exclusion criteria and 40 patients were selected randomly and allocated into two groups, with 20 patients in each group (Group A and Group B). Of these, 36 patients completed the treatment regimen—19 in Group A and 17 in Group B.

Blinding of test drug was done on 23rd March 2024 and code (i.e. BT-1 to BT- 40) was labelled on medicine. BTC and BTS, respectively, at a dosage of 24-26 drops administered for duration of 100 Matra (approximately 5 mins), once daily in the evening for 21 days. The total duration of the trial was 3 weeks, followed by a 2-weeks follow-up period. Observational data were collected on demographic parameters, including age, sex, and occupation, as well as cardinal symptoms such as Vividha Shabda Shravana (perception of various abnormal sounds) and Badhirya (hearing loss), in addition to the Tinnitus Handicap Inventory (THI). The effect of the treatment on all signs and symptoms of the condition were recorded before and after the treatment period. Laboratory investigations such as haemoglobin percentage (Hb%) and random blood sugar (RBS) were conducted for the enrolment of patients. Additionally, pure tone audiometry was performed before and after treatment on patients presenting with hearing loss to assess changes in auditory function. The data were meticulously documented and analysed. A committee was conducted the process for disclosure of code (on 11th September 2024) and reveals that group A received Bilva Taila prepared according to the reference of Chakradatta (BTC), while group B received Bilva Taila prepared on Snehapaka principle according to the reference of Sharangdhara Samhita (BTS).  

The demographic analysis revealed that the maximum patients (32.50 %) belonged to the age group of 31 to 40 years. Female patients constituted 52.50 % of the sample, while married individuals made up 80 %. The majority of participants identified as Hindu (95 %). In terms of occupation, the most represented group was those employed in service positions (45 %), with 85 % of the patients belonging to the lower middle class.

Furthermore, the predominant constitutional types observed were Vata-Pitta Prakriti (62.50 %) and Rajasika Manasa Prakriti (67.50 %). Most patients exhibited Madhyama Satva (62.50 %), Madhyama Samhanana (65 %) and Madhyama Pramana (87.50 %). Additionally, a significant majority demonstrated Madhyama Satmya (95 %), Madhyama Vyayama Shakti (72.50 %), Madhyama Abhyavarana Shakti (87.50 %) and Madhyama Koshtha (57.50 %). These findings indicate a consistent profile among the patient population in this study.

The analysis of dietary habits revealed that Katu Rasa was the predominant dietary preference, identified in 47.50% of the patients as an etiological factor. Among the enrolled patients, Guru (60 %) and Snigdha (55 %) were the most commonly consumed qualities of food. Additionally, the study found that Marut Sevana (82.50 %), Karnakanduyana (57.50 %), and Shrama (52.50 %) were the principal causative factors associated with the condition.

The majority of patients (67.50 %) developed the condition within a year, with 52.50 % reporting a sudden onset of symptoms. Notably, 70 % of patients were experienced a stationary phase of tinnitus. Symptoms were exacerbated in a quiet environment for 87.50 % of the patients. Various abnormal sounds were heard by the patients (i.e. Ringing, whistling, roaring, hissing, etc.)  but most frequently reported auditory symptom was a ringing sound in the ear, observed in 35 % of cases. Furthermore, a family history of tinnitus was absent in all patients (100 %). All patients exhibited symptoms consistent with Karnanada, while only 27.50 % reported associated complaints of Badhirya. 

Both treatment groups exhibited highly significant improvements in Karnanada symptoms and the Tinnitus Handicap Inventory (THI), while no significant changes were observed in Badhirya symptoms. Comparative analysis revealed that relief in Karnanada symptoms was 63.41 % in Group A and 56.76 % in Group B, a difference that was statistically insignificant (P > 0.05). Similarly, for the THI, Group A showed a relief of 67.18% compared to 64.15% in Group B, which also indicates statistical insignificance (P > 0.05). In terms of Badhirya, both groups demonstrated no improvement (0 %), as the maximum enhancement observed in audiometry was only 5 dB, which did not translate into meaningful changes in the scoring pattern.

In Group A, 36.84 % of patients achieved complete remission, while in Group B, this rate was significantly lower at 5.88 %. Marked improvement was noted in 5.26 % of patients in Group A, compared to 11.76 % in Group B. Moderate improvement was reported in 21.05 % of patients in Group A, in contrast to 47.05 % in Group B. Additionally, mild improvement was observed in 10.52 % of patients in Group A and 23.52 % in Group B. Furthermore, 26.31 % of patients in Group A and 11.76 % in Group B exhibited no change in their condition.