The study is designed as a prospective, single-blinded RCT. It will take place in the clinics of Beijing Tongren Hospital, Capital Medical University, and the Acupuncture and Moxibustion Hospital, China Academy of Chinese Medical Sciences (CACMS). Eligible participants will be randomized in a 1:1 ratio to either the EA group (EA plus medication) or the control group (standard medication alone). This pilot trial will apply a longitudinal follow-up design, with a baseline assessment before enrollment (t–1), allocation and intervention initiation at t0, on-treatment follow-ups at week 2 (t1), week 4 (t2), and posttreatment follow-ups at 1 month (t3), 2 months (t4), and 3 months (t5) after intervention completion, barring loss to follow-up. This trial will be reported in accordance with the CONSORT (Consolidated Standards of Reporting Trials)-EHEALTH (see Multimedia Appendix 1) statement, which defines standard reporting items for RCTs [27]. Participant recruitment began on July 15, 2024, with the study scheduled to continue until December 2025. The flowchart is illustrated in Figure 1, and the overall procedure is presented in Table 1.

Inclusion criteria included the following: a diagnosis of ISSNHL [15], defined as sudden hearing loss (≥30 dB) within 72 hours affecting 3 consecutive frequencies, and accompanied by tinnitus; between 18 and 65 years of age at the time of recruitment; pure tone audiometry (PTA) results showing a flat drop audiogram; onset of hearing loss within 1 week before randomization; clear consciousness, normal cognition, and unaffected basic communication.

Exclusion criteria were hearing loss from other causes (eg, congenital deafness, conductive deafness, presbycusis, large vestibular aqueduct syndrome, Meniere disease, tumors, or deafness due to systemic genetic diseases); having received medication or acupuncture treatment within the past 6 months, or having an allergy to the treatment medication; pregnancy or lactation in females; presence of severe systemic diseases or psychiatric disorders; and participation in other trials.

Ethics approval was obtained from the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (approval number TREC2024-KY060). Before the trial begins, researchers must provide participants with detailed information about the clinical trial, including its purpose, procedures, potential benefits and risks, alternative treatment options, and the rights and responsibilities of the participants. Participants will also be informed that they are free to withdraw consent at any time during the study. They must fully understand this information and provide their consent by signing an “informed consent form” before the clinical trial can commence.

Recruitment will be conducted through WeChat (Tencent Holdings Limited) public account notifications, roll-up banners at clinic entrances, and collaboration with community committees for promotion.

Stratified block randomization will be performed according to the study center. Both groups will be assigned in a 1:1 ratio to the EA and control groups using a block size of 4. Weijuan Gang, a statistician from the Evidence-Based Medicine Center at CACMS, will serve as the randomization coordinator and will be responsible for generating the stratified block randomization sequence using SAS 9.3 software (SAS Institute). She will not participate in the trial’s implementation or data analysis. After obtaining informed consent and before initiating treatment, the treating physician at each center will contact the randomization coordinator by phone to receive the randomization number and group assignment.

Because of the nature of acupuncture, it is not possible to blind the acupuncturists or participants. However, steps will be taken to minimize bias from single blinding as much as possible. Acupuncturists will receive specialized training before participating in the study and will be instructed not to discuss treatment procedures or outcomes. They will also be excluded from evaluating the results. Patients will be treated separately to prevent contact between participants. The randomization staff and acupuncturists will have access to the assignment information, but the outcome evaluators and statisticians will remain blinded throughout the entire clinical trial. Statisticians will speculate on the group allocation before data analysis to assess the efficacy of blinding, and unblinding will only occur after the completion of data analysis.

As previous RCTs have not investigated EA as a combination intervention in patients with ISSNHL with tinnitus, it is challenging to determine the optimal sample size through power calculation. Therefore, rather than performing a formal sample size estimation, this trial will adopt a preliminary exploratory clinical pilot design to estimate the appropriate sample size [28]. However, to preliminarily assess the feasibility of the proposed intervention, we will ensure an adequate number of participants in our experimental design by adhering to the established guideline of a minimum of 12 participants per group for pilot studies [29]. A previous study suggested that each group should have a sample size ranging from 20 to 25 cases for exploratory clinical trials assessing the effectiveness of intervention measures [30]. Therefore, in this study, each group will consist of 25 patients, resulting in a total of 50 cases across the 2 groups. To account for a potential dropout rate of 20%, we will recruit a total of 60 patients (30 per group). The results of this study will provide effect size data for calculating sample sizes in future large-scale RCTs.

The control group intervention protocol was designed in accordance with the 2015 Chinese Guidelines for the Diagnosis and Treatment of Sudden Deafness [15]. These guidelines were developed based on extensive RCT data from multicenter clinical studies on sudden deafness in China, incorporating updates from the latest American and German clinical guidelines as well as recent research advancements, ensuring alignment with clinical practice in China [1,4,16]. The treatment regimen for the control group was designed to comprehensively address the inflammation and microcirculatory disturbances associated with ISSNHL through a combination of prednisone, Ginkgo biloba extract, and batroxobin injection. The specific pharmacological interventions are detailed in Table 2.

Patients in the EA group will receive the same treatment as the control group, in addition to EA, which will not interfere with their medication treatment.

The EA group received acupuncture using disposable sterile needles (Hwato Needles; Suzhou Medical Appliance Factory) at acupoints previously identified in studies as functionally related to ISSNHL and tinnitus, including Tinggong (SI19), Tinghui (GB2), Yifeng (SJ17), Yunting area, Anmian, Waiguan (SJ5), Zhongzhu (SJ3), Taichong (LR3), and Taixi (KI3). For limb acupoints, 30-gauge needles (0.25 mm in diameter, 40 mm long) will be inserted to a depth of 10-15 mm. For head acupoints, 32-gauge needles (0.25 mm in diameter, 25 mm long) will be inserted to a depth of 3 mm. A specialized acupuncture technique will be used when needling the Tinggong point (SI19) on the impacted side. The patient will be instructed to slightly open their mouth, and a needle (0.25 mm in diameter, 40 mm long) will be inserted to a depth of approximately 15-25 mm. The assistant will pinch the patient’s nostrils, prompting the patient to take a deep breath, close their mouth, and hold their breath to push air through the Eustachian tube into both ears. During this procedure, the acupuncturist will gently twist the needle until the patient feels a local sensation of soreness or distension. Afterward, the patient will exhale through the mouth, and the acupuncturist will withdraw the needle by approximately 10 mm and leave it in place. Additionally, the Tinghui (GB2) and Yifeng (SJ17) points on the impacted side will be needled and connected to an EA device (KWD-808I type; Great Wall, Yingdi). A sparse wave with a frequency of 2-15 Hz will be applied at an intensity that induces muscle contraction and is tolerable for the patient. The needles will be retained for 30 minutes. Figure 2 provides an operational illustration of the acupuncture technique at the Tinggong (SI19) point, while Figure 3 shows the acupuncture point selection diagram. EA treatment will last for a total of 4 weeks, with 4 sessions per week during the first 2 weeks and 3 sessions per week during the last 2 weeks, conducted every other day.

The principal investigators (JH and XH) will oversee the trial and report any serious adverse events to the Tongren Hospital Ethics Committee. Detailed records of adverse events—including their timing, severity, and treatment—will be maintained. In the event of an adverse reaction, a senior acupuncturist and otolaryngologist will evaluate whether the patient should be excluded from the study, and the clinical supervisor will be informed accordingly. Researchers will document the event details in the case report form (CRF; Multimedia Appendix 2) and ensure follow-up care until the patient stabilizes, with a summary report sent to the relevant authorities. Audiologists, acupuncturists, and nurses will conduct weekly follow-up calls to monitor symptoms and manage potential adverse reactions.

This RCT will adhere to the principles outlined in the Declaration of Helsinki [46]. Written informed consent will be obtained from all participants, with personal data and consent forms securely stored in a locked unit in the ENT (ear, nose, and throat) outpatient department at Tongren Hospital. Each participant will be assigned a unique ID to maintain anonymity, and all data collected in the computer system will be identified only by this ID number. Documentation files (including ID numbers and participant identifiers) will be stored separately from study information files and consent forms. Only the principal investigators and designated team members will have access to the participant ID list and associated information. Clinical data will be collected and recorded by trained research evaluators in our outpatient clinic, initially entered on CRFs, and then into the EpiData system (EpiData Association). Each CRF will undergo double entry by 2 staff members, followed by a consistency check to generate a validation report. Any discrepancies will be investigated and corrected. All paper records will be stored securely in a controlled room with appropriate temperature, humidity, and fire safety measures. Digital files will be securely stored on a computer or external hard drive to prevent data loss. If issues arise during the study, database variables, particularly primary ones, may undergo full or sampled manual checks and be cross-referenced with the CRFs for accuracy.

All efficacy analyses will follow the intention-to-treat principle, including all randomized participants. Statistical analyses will be performed using SPSS version 22.0 (IBM Corp). Continuous variables, including PTA, THI, SAS, and SF-36, will be reported as means (SDs) for normally distributed data, or as medians (IQRs) for nonnormally distributed data. Tinnitus matching (frequency and loudness) will be treated as a categorical variable and summarized as proportions or percentages.

Baseline PTA distributions for both groups will be reported as means (SD) or medians (IQRs). Differences in baseline hearing loss severity will be assessed using the 2-tailed (unpaired) independent samples t test (for normally distributed data) or the Mann-Whitney U test (for nonnormally distributed data). If significant differences are identified, group comparisons will be adjusted for hearing loss severity using analysis of covariance to ensure comparability.

Changes in PTA, THI, SAS, and SF-36 across 6 time points (t0, t1, t2, t3, t4, and t5) will be evaluated using repeated measures analysis of variance for normally distributed data, or the Friedman test for nonnormally distributed data. Changes in tinnitus matching across the 6 time points will be assessed using the Cochran Q test to detect overall differences. If significant, pairwise comparisons will be conducted using the McNemar test with a Bonferroni correction for multiple comparisons.

Group differences in PTA, THI, SAS, and SF-36 at each time point will be analyzed using the independent samples t test (for normally distributed data) or the Mann-Whitney U test (for nonnormally distributed data). If baseline hearing loss severity differs significantly, analysis of covariance will be applied to adjust for this covariate. Differences in tinnitus matching at each time point will be evaluated using the chi-square test or Fisher exact test, as appropriate. Statistical significance will be set at α=.05 (2-sided).

As a pilot study, the primary feasibility outcomes include the proportion of enrolled participants relative to the target sample size (recruitment rate, reported as a percentage), the proportion of participants completing at least 80% of prescribed EA sessions over 4 weeks (adherence rate, extracted from treatment logs and reported as a percentage), the proportion of participants with complete baseline and follow-up data for key measures such as PTA and THI (data completeness, reported as a percentage, with the proportion of missing data reported as a complementary indicator), and the incidence of adverse events during the treatment period (safety outcomes, recorded from session-by-session reports and summarized as total events and incidence rate per 100 person-sessions). These feasibility outcomes will be presented using descriptive statistics, without hypothesis testing.

The treatment guidelines for ISSNHL have been clearly established. However, the treatment protocol for tinnitus, a common comorbid symptom of ISSNHL, remains uncertain [1,47]. This study aims to investigate the potential efficacy and feasibility of EA combined with medication for patients with ISSNHL accompanied by tinnitus. Currently, only a limited number of studies have focused on the treatment of tinnitus, with therapeutic approaches including sound therapy and psychological therapy [48]. Because of the varied nature of tinnitus symptom maintenance, a single treatment modality may not be suitable for all patients [49]. Acupuncture, as one of the most widely accepted complementary and alternative therapies in China, has been explored in prior research for its potential in managing ISSNHL and tinnitus. For instance, Zhou and Jin [50] conducted a retrospective study comparing EA with traditional acupuncture and found that EA was more effective in reducing hearing thresholds and alleviating tinnitus over a 3-month treatment period. Similarly, Zhang et al [51] performed a systematic review and meta-analysis of 12 RCTs, demonstrating that manual acupuncture or EA combined with medication outperformed medication alone in improving hearing outcomes, with some evidence suggesting that EA alone was superior to medication. Additionally, Chen and Jing [52] reported 2 refractory cases where EA alone (12 sessions over 4 weeks) led to complete recovery of unilateral sensorineural hearing loss. However, these findings are limited by low evidence quality and the rare use of tinnitus-specific outcomes (eg, tinnitus matching or THI) as primary end points.

The selection of acupuncture points is primarily based on the following rationale. A study by Huang et al [53] revealed that, through data mining analysis of 112 studies containing 221 prescriptions, the 4 most frequently used acupuncture points were SI19, GB2, SJ17, and SJ3. The SI19-GB2-SJ17 point combination was identified as the core acupoint cluster according to association rule analysis. These peri-auricular acupoints may alleviate tinnitus by stimulating auditory-related nerves and improving blood circulation in the ear region [24,54]. Additionally, scalp acupuncture may exert its effects through the trigeminal nerve and blood circulation regulation, contributing to the improvement of auditory processing and neural activity [55,56].

Most studies currently agree that the earlier patients with ISSNHL receive treatment, the better their prognosis. The study by Byl [57] indicated that patients who received medical attention within 7 days of onset had an approximately 56% recovery rate, whereas those who presented after 30 days had a recovery rate of only 27% (also see [58]). The study by Diao et al [59] also demonstrated that the number of days from onset to treatment was an independent prognostic factor, with shorter time intervals correlating with better outcomes. Therefore, all patients selected for this study were within 7 days of onset. The medication treatment protocol for ISSNHL with tinnitus is the same as that for ISSNHL. The inclusion of multiple variables (ie, multiple drugs) in the standard treatment is driven by the complex pathophysiology of ISSNHL. Research indicates that inflammation is likely a key contributing factor, and corticosteroids such as prednisone are used to reduce inner ear inflammation and edema, thereby improving hearing outcomes [60]. Ginkgo biloba extract, known for its circulation-enhancing and antioxidant properties, may help restore cochlear microcirculation [61]. Batroxobin, a snake venom–derived enzyme with fibrinolytic activity, may improve inner ear blood flow by reducing blood viscosity [62]. This combination of drugs is designed to simultaneously target distinct pathological mechanisms, thereby enhancing overall therapeutic efficacy. The rationale for this combined approach is supported by evidence from studies conducted in China. A retrospective study involving 342 patients with total deafness-type ISSNHL found that adding batroxobin to a treatment regimen of Ginaton and glucocorticoids significantly improved hearing recovery outcomes and maintained plasma fibrinogen levels within a safe and prognostically favorable range [63]. This improvement was particularly notable in terms of hemorheological parameters and peripheral blood T-cell subset reactivity. Additionally, a 2023 meta-analysis further corroborated the efficacy of Ginkgo biloba extract as an adjuvant therapy, suggesting it may outperform corticosteroid monotherapy [64]. These findings support the decision to incorporate multiple pharmacological agents into the standard treatment protocol, aligning with the goal of addressing the multifaceted nature of ISSNHL.

This study innovatively investigates EA for flat-type ISSNHL, integrating traditional Chinese medicine with modern clinical needs to explore a potential nonpharmacological treatment option. However, there are several limitations to this study. First, due to the inability to implement blinding in the intervention measures, there may be some degree of bias, particularly regarding placebo effects and patient expectations, which could interfere with subjective evaluations of treatment outcomes. Moreover, this study does not include a sham acupuncture control, which further increases the potential for bias, as the lack of a placebo control for acupuncture makes it difficult to rule out nonspecific treatment effects. Second, this study only included patients with flat-type ISSNHL, excluding the other 3 types of hearing curves, which may limit the generalizability of the results to a broader population of patients with ISSNHL with tinnitus.

This pilot study evaluates the feasibility of combining EA with medication for flat-type ISSNHL, integrating both subjective and objective outcomes across multiple follow-up time points to assess potential benefits in hearing, tinnitus, anxiety, and quality of life. Using rigorous stratified randomization and high-quality data management, this study generates preliminary evidence on EA’s viability as a complementary therapy, laying the groundwork for the design and sample size estimation of future large-scale multicenter RCTs to advance nonpharmacological treatment options for ISSNHL.