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 引言：耳鸣（Tinnitus）是一种难治性临床症状，患者对治疗的应答反应存在个体差异。根据其发病诱因与伴随疾病的不同，临床可对其进行多种分类。
研究目的：提出一种统一且可量化的持续性耳鸣分类方法，依据患者通过测听仪（audiometer）呈现的自然声或日常生活声感知，将其与纯音（Pure Tone）或噪声（Noise）进行对比，并区分其音调高低（高频/低频）。
研究方法：本研究共纳入110例性别不限的成年患者，均为耳鸣门诊（Tinnitus Outpatient Clinic）就诊患者，纳入与排除标准参照既定方案。所有受试者均接受耳鼻咽喉科及听力学检查，包括音调匹配测试、响度匹配测试、视觉模拟评分法（Visual Analog Scale, VAS）、耳鸣残疾量表（Tinnitus Handicap Inventory, THI）以及最小掩蔽级（Minimum Masking Level, MML）评估。
研究结果：在110例患者中共检出181例次耳鸣主诉（按耳鸣类型与患耳区分），其中纯音型耳鸣93例次（占比51%），噪声型耳鸣88例次（占比49%）；低频耳鸣19例次，高频耳鸣162例次。纯音型耳鸣患者的视觉模拟评分均值为5.4.07，响度匹配均值为12.31分贝；噪声型耳鸣患者的视觉模拟评分均值为6.66，响度匹配均值为10.51分贝。本研究将110例患者依据耳鸣类型分为纯音型、噪声型及多发耳鸣三组，其中多发耳鸣组的耳鸣残疾量表评分最高，均值为61.38。最小掩蔽级评估采用白噪声（White Noise）与窄带噪声（Narrow Band）作为掩蔽声，测试频率为500Hz与6000Hz。结果显示，纯音型与多发耳鸣组的评估结果存在相似性；而在噪声型耳鸣组中，采用低频窄带噪声测试时得到了不同的应答反应。
研究结论：将持续性耳鸣按纯音型或噪声型分类，并结合其高频/低频分布特征与各项听力学指标进行区分，可帮助我们深入了解耳鸣的特异性表现及其对患者生活质量的影响。