I. Behavioural tests
a) Pure-tone audiometry: This test measures the sensitivity of hearing. During the test, the participant will listen to a range of pure tones of different frequencies and gives behavioural response such as pressing a button or raising his/her hand. Hearing thresholds will then be plotted on a graph called audiogram (a graph showing intensity as a function of frequency).
b) Speech audiometry: This test uses speech instead of pure tones as stimuli. During the test, the participant will listen to speech material such as monosyllabic words, short phrases or sentences and repeats the stimuli as accurately as possible. Speech material in the test will be given at different volume to measure the participant’s speech recognition threshold (SRT). This test provides information on how well one recognises speech.
II. Non-behavioural / objective or physiological tests
a) Immittance Audiometry:
i) Tympanometry: This test is used to inspect middle-ear functioning including the mobility of the eardrum and the conduction of middle-ear ossicles (bones in the middle ear). During the test, an earplug will be placed into the participant’s ear. The device will change the air pressure in the ear canal and thus measure the energy transmission through the middle ear.
ii) Acoustic reflex test: When presented with a high-intensity sound stimulus, the stapedius and tensor tympani muscles of the ossicles in the middle ear contract. This is an involuntary muscle contraction that occurs in the middle ear in response to high-intensity sound stimuli. This test evaluates the middle ear function.
c) Otoacoustic emission test: Otoacoustic emissions refer to the low-intensity sound produced by the cochlea. This test examines cochlear status in the inner ear, specifically, the outer hair cell function.
d) Evoked auditory potentials: This test measures the brain wave activity that occurs in response to sound. The response is collected through electrodes placed on the participant’s scalp and earlobes. This test helps diagnose nervous system problems and hearing loss.
I. 行為聽力檢查
a) 純音聽力檢查:量度聽覺靈敏度。進行檢查時,受試者會聽到不同音頻的純音,並以行動如舉手或按鈕作出反應。聽力閾值會根據分貝和頻率在聽力圖上標示出來。
b) 言語聽力檢查:此檢查讓受試者聆聽語音如單字、詞語或句子,並複述所聽到的語音材料。在檢查時,語音材料會以不同音量播出,以量度受試者的言語聽力閾值,即受試者可辨識語音材料的最低聽覺水平。此檢查可檢測受試者辨識語音的能力。
II. 非行為/客觀或生理聽力檢查
a) 導抗聽力檢查
i) 鼓室圖檢查:此檢查用於檢測中耳功能如耳膜活動和聽小骨傳導。檢查時會把一枚耳塞放進受試者的耳朵,儀器會改變耳道內的氣壓,從而量度通過中耳的能量傳輸。
ii) 聽反射檢查:當受強烈聲音刺激,中耳鐙骨肌和鼓膜張肌就會收縮。此肌肉收縮乃中耳對強烈聲音作出的反射反應。此檢查有助測試中耳功能。
c) 耳聲發射:耳聲發射是指耳蝸產生的微弱聲音。耳聲發射檢查檢測內耳耳蝸外毛細胞功能。
d) 聽覺誘發電位:此檢查透過貼在受試者皮膚和耳珠上的電極貼,量度聽到聲音時的神經電流反應,有助診斷聽力損失或神經系統問題。