Psychoacoustic classification of persistent tinnitus

Abstract Introduction: Tinnitus is a difficult to treat symptom, with different responses in patients. It is classified in different ways, according to its origin and associated diseases. Objective: to propose a single and measurable classification of persistent tinnitus, through its perception as sounds of nature or of daily life and its comparison with pure tone or noise, of high or low pitch, presented to the patient by audiometer sound. Methods: A total of 110 adult patients, of both genders, treated at the Tinnitus Outpatient Clinic, were enrolled according to the inclusion and exclusion criteria. Otorhinolaryngologic and Audiological, Pitch Matching and Loudness, Visual Analog Scale, Tinnitus Handicap Inventory and Minimum Masking Level assessments were performed. Results: In these 110 patients, 181 tinnitus complaints were identified accordingly to type and ear, with 93 (51%) Pure Tone, and 88 (49%) Noise type; 19 at low and 162 at high frequency; with a mean in the Pure Tone of 5.4.07 in the Visual Analog Scale and 12.31 decibel in the Loudness and a mean in the Noise of 6.66 and 10.51 decibel. For Tinnitus Handicap Inventory and Minimum Masking Level, the 110 patients were separated into three groups with tinnitus, Pure Tone, Noise and multiple. Tinnitus Handicap Inventory higher in the group with multiple tinnitus, of 61.38. Masking noises such as White Noise and Narrow Band were used for the Minimum Masking Level at the frequencies of 500 and 6000 Hz. There was a similarity between the Pure Tone and Multiple groups. In the Noise group, different responses were found when Narrow Band was used at low frequency. Conclusion: Classifying persistent tinnitus as pure tone or noise, present in high or low frequency and establishing its different characteristics allow us to know its peculiarities and the effects of this symptom in patients' lives.摘要及引言：耳鸣（Tinnitus）是一种难治性症状，患者对其应答存在个体差异。临床可根据其发病根源与伴随疾病的不同，采用多种方式进行分类。 研究目的：本研究旨在基于患者通过听力计呈现的测听声，将其感知为自然声或日常声的持续性耳鸣，与纯音（Pure Tone）或噪声（Noise）、高/低音调进行对比，提出一种统一且可量化的持续性耳鸣分类方法。 研究方法：本研究纳入110名于耳鸣门诊就诊的成年患者，涵盖两性，入组严格遵循纳入与排除标准。对所有受试者完成耳鼻咽喉科及听力学检查、音调匹配与响度测试、视觉模拟评分法（Visual Analog Scale, VAS）、耳鸣残障指数（Tinnitus Handicap Inventory, THI）以及最小掩蔽级（Minimum Masking Level, MML）评估。 研究结果：在这110例患者中，共识别出181例按类型与患耳划分的耳鸣主诉：其中纯音型93例（占比51%），噪声型88例（占比49%）；低频分布19例，高频分布162例。纯音型耳鸣的视觉模拟评分均值为5.4.07，响度均值为12.31分贝；噪声型耳鸣的视觉模拟评分均值为6.66，响度均值为10.51分贝。针对耳鸣残障指数与最小掩蔽级，将110例患者分为三类耳鸣组别：纯音型、噪声型及复合型。复合型耳鸣患者的耳鸣残障指数最高，均值达61.38。最小掩蔽级测试采用白噪声（White Noise）与窄带噪声（Narrow Band）作为掩蔽声，测试频率为500Hz与6000Hz。纯音型与复合型耳鸣组间表现相似；而在噪声型耳鸣组中，低频段使用窄带噪声时观测到不同的应答反应。 研究结论：将持续性耳鸣按照纯音型或噪声型进行分类，并结合其高频/低频分布特征明确各项差异，有助于深入了解该症状的特殊性及其对患者生活造成的影响。