Exploring P300 Responses in Tinnitus: Linking Cognitive and Audiological Assessments

Abstract

Aim

The study aimed to evaluate the effect of tinnitus masking on cognitive functioning and the efficacy of tinnitus retraining therapy in reducing the severity of tinnitus handicap.

Method

The study recruited 15 subjects (mean age = 47.1 ± 11.5) with unilateral chronic tinnitus (6 participants with right-ear tinnitus and 9 participants with left-ear tinnitus); and mild to moderate sensorineural hearing loss. Conducted in two phases, Phase 1 comprised case history, audiometric testing, tinnitus matching, and THI-Bangla assessment. Phase 2 involved P300 administration followed by a 60-session tinnitus retraining therapy (online-offline modality), concluding with post-therapy P300 and THI-Bangla assessments. Therapy outcomes were evaluated by improvements in P300 latency and amplitude and THI-Bangla scores.

Results

A significant improvement observed post-therapy, with reductions in mean P300 latency for both left (p < 0.001) and right (p < 0.001) ears. Mean P300 amplitude also increased significantly post-therapy for left (p < 0.001) and right (p < 0.001) ears. THI scores also declined substantially (p < 0.001), with a post-therapy mean THI score of 17.80 (SD = 4.64) for males and 12.20 (SD = 3.42) for females, revealing a significant difference (p = 0.033).

Conclusion

These findings support the efficacy of tinnitus retraining therapy in reducing tinnitus related distress and enhancing cognitive processing, as evidenced by P300 improvements.

Introduction

Tinnitus, often described as a “sensation of low-pitched rushing, hissing, or ringing in the ears,” refers to the internal perception of sound without external stimuli, as defined by the International Classification of Function, Disability, and Health [1]. It affects approximately 10–20% of the global population, with severe cases reported in about 4% [2]. Prevalence estimates vary widely, ranging from 4 to 32% among adults [3–5]. In the U.S. alone, 40–50 million individuals are affected, with 10–12 million requiring professional support and 2.5 million experiencing debilitating symptoms [6]. Despite its diverse clinical features and underlying causes, tinnitus often involves maladaptive neural changes within the central auditory system following cochlear damage, which can result in persistent tinnitus perception [7]. Epidemiological studies have identified prolonged noise exposure from occupational or recreational activities as a significant and potentially modifiable risk factor [8].

Neurophysiological research links tinnitus to abnormal activity in the auditory pathway, particularly within the inferior colliculus and auditory cortex [9]. Damage to hair cells or auditory nerve fibers, often caused by acoustic trauma or ototoxic substances, leads to hyperactivity in the cochlear nucleus and inferior colliculus due to increased central gain [10]. Additionally, interactions between the auditory and limbic systems—including regions like the amygdala—highlight the emotional distress associated with tinnitus, impacting psychological well-being [10, 11].

Assessment of tinnitus is inherently complex, given its subjective nature. A comprehensive evaluation includes audiometric and electrophysiological tests such as acoustic reflexes, tympanograms, and auditory brainstem response assessments [12]. A proposed essential tinnitus evaluation guidelines, which was widely accepted in clinical practice, included a thorough audiologic history, site of lesion testing, and tinnitus-specific measurements like loudness matching, pitch matching, and minimum masking levels (MML) [13]. Psychoacoustic measurements, including tinnitus loudness and pitch matching, minimum masking levels (MML) [14], and residual inhibition (RI) testing, are essential components of tinnitus evaluation [15]. Quality-of-life assessment tools, such as the Tinnitus Handicap Inventory (THI) and Beck Depression Inventory (BDI), further aid in measuring cognitive and emotional impacts [16, 17].

Event-related potentials, specifically the P300 wave, provide insights into cognitive processing in tinnitus patients [18]. The P300 wave, a centro-parietal positivity occurring approximately 300 ms after stimulus presentation, reflects recognition of relevant information and involves two subcomponents: P3a and P3b [19]. The P3a, originating in the frontal lobes, indicates automatic cognitive processing and sensitivity to stimulus novelty [20], while the P3b, localized to parietal regions, signifies active cognitive discrimination and memory schema updating [21, 22]. P300 amplitude, influenced by factors such as stimulus modality and task conditions, is considered a marker for memory-related brain activity and context-updating processes. The event-related potential (ERP) P300 is an endogenous response influenced by cognitive processes [23], particularly attention, and primarily elicited using auditory or visual oddball paradigms [24].

P300 has been linked to tinnitus, which may affect cognitive functions such as attention and working memory [25]. Research indicates that various brain networks, including the frontal cortex and limbic system, are involved in tinnitus perception, potentially contributing to distress and attention disorders in affected individuals [26, 27]. The P300 test involves standard and target stimuli, requiring selective attention to generate a reliable P3b peak, which serves as a strong indicator of attentional capacity across populations [25]. Patients with tinnitus often exhibit changes in latency and amplitude of auditory ERPs compared to control groups, highlighting alterations in auditory attention [28]. Additionally, there is limited literature on how Tinnitus Retraining Therapy (TRT) may influence late latency potentials such as the P300.

Hence, the aim of this study is to evaluate the effect of tinnitus masking on cognitive functioning and the efficacy of tinnitus retraining therapy in reducing the severity of tinnitus handicap. The objectives include assessing P300 values in patients with mild to moderate sensorineural hearing loss and unilateral tinnitus, examining the impact of tinnitus on cognitive functioning through P300 measurements, and evaluating the quality of life of subjects prior to tinnitus retraining therapy using the Tinnitus Handicap Inventory (THI). Additionally, the study aims to compare the latency and amplitude of P300 between male and female subjects before and after tinnitus retraining therapy, provide tinnitus retraining therapy to all subjects with unilateral tinnitus, and draw therapeutic inferences by comparing pre- and post-therapy results using P300 and THI. Lastly, the study will investigate the overall impact of tinnitus retraining therapy on cognitive functioning and quality of life, focusing on effect size.

Methods

Phase 1: Subject Selection

This quasi-experimental study investigated the effects of tinnitus retraining therapy (TRT) on cognitive markers in audiological tests i.e., P300 latency and amplitude in patients and behavioural markers and quality of life in Tinnitus Handicap Inventory (THI) with mild to moderate sensorineural hearing loss (SNHL). Conducted at AYJNISHD, RC Kolkata, the study included 15 adults (10 males and 5 females)with mean age: 47.1 ± 11.5 years (6 participants with right-ear tinnitus and 9 participants with left-ear tinnitus) selected from an initial pool of 50 subjects based on strict inclusion criteria.

The inclusion criteria specified:

• Adults aged 20–60 years.

• Diagnosed with mild to moderate SNHL and an “A” type tympanogram.

• Presence of unilateral chronic subjective tinnitus persisting for at least six months.

• Minimum educational level of higher secondary education with proficiency in English, Hindi, or Bengali, ensuring accurate comprehension of instructions and questionnaires.

Subjects with pulsatile tinnitus, loudness tolerance issues, external or middle ear disorders, or prior exposure to tinnitus management programs were excluded. These criteria ensured homogeneity within the sample while controlling for factors that could interfere with P300 recordings or outcomes.

The study opted for a within-subject design due to the high variability in individual responses to tinnitus therapy. This approach allowed for more precise measurement of changes in cognitive and quality-of-life parameters while avoiding ethical concerns associated with withholding treatment from a control group. Such designs are commonly employed in tinnitus research where individualized responses are critical to therapeutic evaluation.

Ethical Consideration

Ethical considerations were carefully addressed. Written consent was obtained from each participant, informing them about the study’s methodology, potential outcomes, and the use of their data for analysis and publication purposes. The study synopsis was submitted to the Ethical committee of AYJNISHD, RC, Kolkata and after the detailed discussion meeting the clearance and approval was received which certified that the study was performed in accordance with the ethical standards [29].

Hearing Threshold Testing

Hearing thresholds were measured using a Maico MA53 audiometer with TDH 39 supra-aural headphones and a B71 bone vibrator at frequencies of 500 Hz, 1 kHz, 2 kHz, 4 kHz, and 8 kHz.

• Psychoacoustic Assessment: Tinnitus was assessed using pitch matching, loudness matching, minimal masking levels (MML), and residual inhibition, following the General Testing Strategy for Tinnitus Matching [30].

• Pitch Matching: Subjects verbally matched the pitch of their tinnitus to a presented stimulus (pure tone/noise). This was done twice to ensure accuracy. An octave confusion test was conducted to confirm the matched pitch.

• Loudness Matching: The loudness of tinnitus was matched to the pitch-matched tone using a 5 dB step size resolution in both dB HL and dB SPL.

• Minimal Masking Level (MML): The lowest level of broadband or narrowband noise that rendered the tinnitus inaudible was measured. MML testing was done monaurally for unilateral tinnitus cases.

• Residual Inhibition: Pulsed acoustic stimuli of fixed duration and intervals were presented in the stimulus ear. The level was increased in 5 dB steps until the tinnitus was suppressed, both during and between stimuli presentations.

P300 Recording

The P300 was recorded using a two-channel Smart EP USB system (Intelligent Hearing System, Miami, USA). The test was administered before the beginning of phase- 2 and then after completion of phase 2. Electrodes were placed according to the international 10–20 system, with the vertex (Cz) as the reference and ground electrode (Fpz) on the forehead. ER-3 A insert earphones were used, and subjects were instructed to count the occurrences of the rare stimulus. Electrode impedance was maintained below five ohms. To minimize artifacts from eye movement, participants were asked to focus on a visual target.

Tinnitus Handicap Inventory (THI)

The THI was administered before therapy to measure the impact of tinnitus on daily life. These pre-therapy scores were compared with post-therapy scores in Phase 2.

Phase 2: Tinnitus Retraining Therapy (TRT)

Tinnitus retraining therapy (TRT) was administered in a soundproof, calibrated room within the audiovestibular lab at the institute. Each session followed evidence-based practices, incorporating a combination of directive counseling and sound therapy to facilitate long-term habituation. During directive counseling, subjects received detailed information about tinnitus mechanisms and the habituation process. This education aims to demystify tinnitus, addressing participants’ emotional reactions to tinnitus and provide coping strategies for managing stress associated with the condition [31].Clinical psychologists and qualified audiologists have attended individual sessions for Directive counseling, aimed at reshaping their emotional and cognitive response to tinnitus, as outlined in Jastreboff and Hazell’s TRT framework [32]. For sound therapy, broadband noise (BBN) was presented at the minimum masking level (MML) plus 20 dB [33]. This level of sound was selected to provide sufficient masking while minimizing any discomfort. The therapy protocol also adhered to the guidelines set forth by Jastreboff and Jastreboff [34], which emphasize the importance of pairing the auditory stimulus with a non-threatening environment to aid habituation.

Sessions were delivered twice daily, with each session lasting 30 min and separated by a one-hour interval, for a total of 30 sessions. During each session, subjects engaged in calming activities such as light progressive muscle relaxation exercises, light reading, simple puzzles, or gentle drawing exercises to promote relaxation and help the subjects adapt to the masking sound. These activities also helped reinforce the concept of relaxation [30], as a complementary component in the TRT process. The therapy sessions were closely monitored via CCTV with permission of participants, to ensure adherence to the established protocol and to maintain subject comfort.

Statistical Analysis

Descriptive statistics were used to calculate the mean, median, and standard deviation of changes in latency (ms) and amplitude (µV) for P300. The statistical analysis was carried out using SPSS (version 21.0). The Shapiro-Wilks test of normality was performed, confirming that the data followed a normal distribution (p > 0.05).

Parametric tests were applied, including:

Independent two-sample t-test to assess significant differences between male and female Subjects.Paired sample t-test to evaluate significant differences between pre- and post-test scores for latency and amplitude.

A significance level of 0.05 or 0.01 was used for all tests.

Results

The results of this study are presented to address the research objectives, focusing on the effects of tinnitus retraining therapy on cognitive functions, as measured by P300 amplitude and latency, and on the quality of life. Results are presented in the following subsections, including P300 amplitude and latency, Tinnitus Handicap Inventory-Bangla scores, gender differences, and effect size of tinnitus retraining therapy.

Comparison of Pre- and Post-tinnitus Retraining Therapy: P300 Amplitude and Latency

Significant changes in P300 latency and amplitude were observed following tinnitus retraining therapy, as detailed in Table 1. For the left ear, latency decreased from 410.47 ms to 330.27 ms (t = 10.054, p = 0.000**), while for the right ear, it decreased from 384.93 ms to 312.40 ms (t = 9.159, p = 0.000**). Similarly, P300 amplitude increased, with the left ear rising from 4.47 µV to 6.32 µV (t= -4.092, p = 0.000**) and the right ear increasing from 5.98 µV to 7.71 µV (t = 4.941, p = 0.000**). These results indicate that tinnitus retraining therapy significantly enhances cognitive processing related to auditory stimuli, as reflected in both latency and amplitude changes. Additionally, it was noted that the right ear had better results, which might be because there were more left ear tinnitus patients than right, which could account for the right side advantage.

Table 1.

Comparison between pre and post for latency and amplitude: descriptive statistics and paired samples t-test (n = 15)

Variables	Ear	Test	Mean	SD	t(14)	p-value
P300 LATENCY	Right	Pre	384.93	64.74	9.159	0.000**
		Post	312.40	42.43
	Left	Pre	410.47	76.91	10.054	0.000**
		Post	330.27	52.92
P300 AMPLITUDE	Right	Pre	5.98	3.55	4.941	0.000**
		Post	7.71	3.20
	Left	Pre	4.47	3.39	-4.092	0.000**
		Post	6.32	2.44

^* Indicates significant at P < 0.05 ^** Indicates significant at P < 0.01

Comparison of Pre- and Post-tinnitus Retraining Therapy: Tinnitus Handicap Inventory

As shown in Table 2, the Tinnitus Handicap Inventory (THI) scores revealed a significant reduction following tinnitus retraining therapy. The mean THI score decreased markedly from 57.80 before therapy to 15.93 afterward (t = 46.297, p = 0.000**). This finding indicates a substantial improvement in the subjects’ perception of tinnitus severity after the intervention, suggesting that tinnitus retraining therapy effectively alleviates tinnitus-related distress.

Table 2.

Comparison between pre and post for THI scores: descriptive statistics and paired samples t-test:

Test	Mean	SD	t(14)	p-value
Pre	57.80	7.07	46.297	0.000**
Post	15.93	4.96

^* Indicates significant at P < 0.05 ^** Indicates significant at P < 0.01

Gender Differences among pre and post Therapy P300 Latency and Amplitude

The P300 latency and amplitude were measured for both left and right ears, among the genders, before and after the tinnitus retraining therapy. The gender comparison for P300 latency and amplitude revealed no significant differences between male and female subjects, both before and after tinnitus retraining therapy, as shown in Table 3. Similarly, there were no significant differences in P300 amplitude between the genders for either ear. Overall, the study found no significant gender differences in P300 latency and amplitude, leading to no significant difference in P300 latency and amplitude between male and female subjects before and after tinnitus retraining therapy.

Table 3.

Comparison between pre and post for latency and amplitude between males and females: descriptive statistics and paired samples t-test:

Variables	Ear	Test	Male (n = 10)		Female (n = 5)		t(13)
			Mean	SD	Mean	SD
P300 LATENCY	Right	Pre	398.30	66.25	358.20	58.77	1.143
		Post	317.50	47.43	302.20	32.32	0.644
	Left	Pre	437.60	71.85	356.20	59.71	2.174
		Post	345.80	54.05	299.20	37.67	1.716
P300 AMPLITUDE	Right	Pre	5.33	3.42	7.28	3.82	-1.004
		Post	7.25	3.17	8.62	3.43	-0.767
	Left	Pre	3.82	3.91	5.75	1.66	-1.040
		Post	5.95	2.84	7.05	1.30	-0.816

^* Indicates significant at P < 0.05 ^** Indicates significant at P < 0.01

Gender Differences in THI Scores

The analysis of gender differences in Tinnitus Handicap Inventory (THI) scores revealed that the mean score before the intervention was 60.00 (SD + 6.78) for males and 53.40 (SD + 5.94) for females, with an independent samples t-test indicating no statistically significant difference between the two groups (t(13) = 1.844, p = 0.088). After the intervention, the mean THI score for males decreased to 17.80 (SD + 4.64), while for females, it dropped to 12.20 (SD + 3.42). The independent samples t-test revealed a statistically significant difference between the groups post intervention (t(13) = 2.378, p = 0.033). In summary, as depicted in Table 4, while there were no significant gender differences in THI scores before the intervention, significant differences emerged after treatment, indicating that the intervention was more effective for females than males.

Table 4.

Comparison between male and female for THI score: descriptive statistics and independent two samples t-test:

Test	Male (n = 10)		Female (n = 5)			t(13)
	Mean	SD	Mean	SD
Pre	60.00	6.78	53.40	5.94	1.844
Post	17.80	4.64	12.20	3.42	2.378

^* Indicates significant at P < 0.05 ^** Indicates significant at P < 0.01

Effect Size of Tinnitus Retraining Therapy

The effect size analysis indicated a substantial impact of tinnitus retraining therapy on various measures. Specifically, the effect size for Tinnitus Handicap Inventory (THI) scores was found to be 6.86, which is considered a “huge” effect [35]. This suggests a significant reduction in tinnitus-related handicap and a meaningful improvement in Subjects’ perceived tinnitus severity and associated distress. In terms of P300 latency and amplitude, effect sizes reflected moderate to large effects. For P300 latency, the effect sizes were 1.33 for the right ear and 1.21 for the left ear, both classified as large” effects [35]. These findings indicate a notable reduction in the time required for the brain to process auditory stimuli, suggesting improved cognitive processing related to tinnitus. For P300 amplitude, the effect sizes were 0.51 for the right ear and 0.63 for the left ear, categorized as “medium” effects [35]. These values suggest a moderate enhancement in the amplitude of the P300 waveform, which reflects cognitive processing and attention. Overall, the results indicate that tinnitus retraining therapy has a positive impact on both cognitive functioning and the subjective experience of tinnitus. In summary, the effect sizes demonstrate that tinnitus masking significantly reduced tinnitus-related handicap, as indicated by THI scores, while also improving auditory cognitive processing (P300 latency) and attention-related neural activity (P300 amplitude). These findings underscore the potential efficacy of tinnitus masking interventions in alleviating the adverse effects of tinnitus on individuals’ quality of life and cognitive functioning. Consequently, the results reveal a positive impact of tinnitus retraining therapy on both neurophysiological measures.

(P300 latency and amplitude) and the subjective assessment of tinnitus severity (THI scores), suggesting that the therapy effectively alleviated the subjects’ tinnitus symptoms.

Discussion

The purpose of the current study was to investigate the effect of tinnitus on P300 by.

focusing on the implications of tinnitus retraining therapy on the cognitive functions of subjects with unilateral tinnitus (6 right-ear tinnitus and 9 left-ear tinnitus); therefore, the study followed a structured protocol consisting of assessment of.

cognitive function in subject with tinnitus using P300 and the overall quality of life using THI Bangla. Followed by administration of 60 sessions of tinnitus retraining therapy to all subjects.

P300 Amplitude and Latency

The study examined the impact of tinnitus retraining therapy on P300 latency and amplitude among 15 subjects, revealing significant changes pre- and post-therapy for both ears. Results demonstrated a notably shorter P300 latency following therapy, suggesting enhanced cognitive processing abilities. Similarly, P300 amplitude increased post-therapy, indicating stronger brain responses [18]. These findings are significant, as cognitive processing is vital for daily functions like attention, memory, and decision-making [36]. Overall, this evidence supports the effectiveness of tinnitus retraining therapy in improving cognitive functions, offering a potential objective measure for assessing tinnitus severity and guiding future therapeutic strategies targeting neural processes impacted by tinnitus. In line with the current study, the impact of auditory stimulation on tinnitus was examined and its effect on late-latency auditory evoked potentials (AEPs) [28]. It was observed that tinnitus suppression through auditory stimulation could alter late-latency AEPs. The study with 40 Subjects—20 with tinnitus and 20 controls—showed that, following auditory stimulation and tinnitus retraining therapy (TM), there was a significant improvement in P3a amplitude and latency among tinnitus patients, along with better Dichotic Digit Test (DDT) and Tinnitus Handicap Inventory (THI) scores [28]. This suggests that tinnitus suppression may engage typical neurophysiological mechanisms, supported by both electrophysiological and behavioral evaluations [28]. Similarly, another study found that tinnitus patients with normal hearing exhibited longer P300 latencies and significantly lower amplitudes compared to controls, indicating potential attention deficits linked to tinnitus [36]. It was concluded that P300 may serve as a valuable tool in assessing cognitive function and tinnitus severity [36]. Together, these studies reinforce the utility of P300 measures in understanding the neurocognitive effects of tinnitus and assessing intervention.

outcomes.

Tinnitus Handicap Inventory-Bangla

The current study highlighted a significant improvement in Tinnitus Handicap Inventory (THI) scores following tinnitus retraining therapy, with post-treatment scores markedly lower than pre-treatment levels (pre: 57.80, post: 15.93; p = 0.000**). This suggests a reduction in the severity and impact of tinnitus, with Subjects reporting better emotional health, reduced functional and catastrophic effects, and improved sleep quality. The findings support tinnitus retraining therapy as a.

promising intervention for managing tinnitus-related distress by providing sound enrichment, which encourages neural adaptation and reduces conscious awareness of tinnitus. Similarly, a study found a significant reduction in THI scores and other tinnitus parameters among patients following a four week tinnitus masking treatment [37]. This study included a thorough evaluation of clinical and audiological parameters, further supports the efficacy of masking therapy as a cost-effective and.

non-invasive method for tinnitus relief [37]. Overall, these results underscore the positive impact of tinnitus retraining therapy on quality of life and emotional well-being in individuals affected by tinnitus.

Gender Difference in P300 Variables

This study investigated potential gender differences in P300 latency and amplitude among tinnitus patients before and after tinnitus retraining therapy, focusing on neurophysiological markers that reflect cognitive processing and attentional mechanisms. Findings indicated no significant differences between male and female subjects in P300 latency or amplitude for either ear, both before and after the therapy, as shown in Table 3; Fig. 1 (A) and (B). This outcome suggests that gender does not significantly impact the time required for the brain to process auditory stimuli (P300 latency) or the intensity of the brain’s response to these stimuli (P300 amplitude) in the context of tinnitus treatment. Consequently, the observed improvements in P300 measures following masking therapy likely reflect therapeutic effects that are uniformly beneficial across genders, highlighting tinnitus retraining therapy as a gender-neutral intervention option.

Fig. 1.

(A) Pictorial representation of P300 waveform : Pre-Therapy recording; (B)

Pictorial representation of P300 waveform: Post-Therapy recordings.

These findings align with another study which observed longer P300 latencies in female Subjects across specific electrode sites (Fz, Cz, and Pz) compared to males, indicating a slightly longer period between stimulus onset and peak amplitude in females, though no significant differences were found in P300 amplitude [38]. the findings of the study reinforce the current findings, indicating that neurophysiological mechanisms underlying cognitive processing and attentional mechanisms in tinnitus patients are comparable across genders. The consistent findings across studies suggest that tinnitus retraining therapy may benefit patients equally, regardless of gender, enhancing its applicability as a generalizable intervention for tinnitus-related cognitive effects.

Gender Difference in THI-B

The comparison of Tinnitus Handicap Inventory-Bangla (THI-Bangla) scores pre- and post-tinnitus masking therapy reveals gender-specific responses to treatment. Before therapy, males had a mean THI score of 60.00 (SD = 6.78) and females scored 53.40 (SD = 5.94), with no significant difference. Post-intervention, scores significantly decreased for both groups, but more notably for females, who had a mean of 12.20 (SD = 3.42) compared to males’ 17.80 (SD = 4.64) (t (13) = 2.378, p = 0.033). This has potential implications for gender-sensitive tinnitus management, as personalized interventions that account for gender-specific characteristics may enhance treatment.

efficacy. The findings align with research which observed gender-based differences in response to a multimodal tinnitus treatment among 1,628 chronic tinnitus patients [39]. Their analysis, employing machine learning on self-report variables, revealed that female patients reported higher tinnitus related distress, psychological symptoms (melancholy, stress), and positive treatment responses [39]. Their study of chronic tinnitus patients indicated that females reported greater distress but also more significant treatment benefits, whereas males noted more physical discomfort but improved overall health [39]. The results underscore the value of gender-sensitive, personalized tinnitus care to optimize outcomes across diverse patient profiles.

Tinnitus Retraining Therapy: Effect Size

In this study, we utilized Cohen’s d to evaluate the effect size of tinnitus retraining therapy on cognitive abilities, as reflected in P300 latency, P300 amplitude, and Tinnitus Handicap Inventory (THI) scores. The findings revealed large effect sizes for P300 latency, measuring 1.33 for the right ear and 1.21 for the left ear, indicating significant reductions post-intervention (p = 0.000**). For P300 amplitude, the effect sizes were moderate at 0.51 for the right ear and 0.63 for the left ear, also statistically significant (p = 0.000**). The THI scores showed a remarkable effect size of 6.86,

reflecting a substantial decrease in tinnitus-related distress (p = 0.000**). These results demonstrate the efficacy of tinnitus retraining therapy in alleviating symptoms and enhancing auditory processing, highlighting the practical importance of these observed changes. Supporting studies corroborate these findings. One such study compared tinnitus masking (TM) and tinnitus retraining therapy (TRT) in 123 patients, revealing that TM provided significant short-term relief, while TRT showed incremental long-term benefits [40]. Additionally, another study examined tinnitus sound therapy through hearing aid fittings, reporting a large effect size (Cohen’s.

d = 1.25) and varying levels of tinnitus masking based on individual hearing profiles [41]. Together, these studies reinforce the effectiveness of sound-based interventions in managing tinnitus and improving patients’ quality of life, while also emphasizing the need for further research to personalize treatment strategies.

Summary and Conclusion

Overall, this study provides compelling evidence that tinnitus retraining therapy positively affects her P300 latency and amplitude. The results suggest that treatment shortened her P300 latency and increased P300 amplitude in both left and right ears. This suggests that the right ear may respond better to tinnitus-masking therapy and may be an important target for effective treatment. Further studies are needed to fully understand the underlying mechanisms and clinical implications of right ear benefits associated with tinnitus management.

Declarations

Competing Insterest

This study received no internal or external funding, and the authors declare that there are no conflicts of interest regarding the publication of this paper.