Question #1
The term impedance means medium resistance movements. When sound is transferred from a low impedance to a high impedance medium, all of the acoustical energy is reflected. The purpose of the middle ear is to fix the impedance mismatch between the areas of the sound as it comes down from the air in the ear canal. The ear canal also attempts to fix the impedance mismatch as sound moves from to the cochlea to the oval window of the cochlea (Mason 302). The cochlea has perilymph and endolymph, which contain a lot of fluids. Therefore, when sound travels to the ear, there is impedance, and there will be a loss of energy because air conducted sound has to travel to cochlea fluids that bring about the resistance. To compensate for the lost sound energy, the tympanic membrane, the malleus, incus, and the stapes does the impedance matching. The middle ear provides an impedance indent matching circuit so that the impedance of the ear and the impedance of the liquid are better managed.
Question #2
- An audiometry test measures the ability of an individual to hear different sounds, frequency, or pitch. Frequency is the number of sound waves that pass a fixed point per second or the number of times a string vibrates per second. Frequency metrics are in hertz. On the other hand, the pitch describes the frequency of the sound (Dawson et al.). A higher frequency causes a high pitch and vice versa. Therefore, frequency and wavelength determine the pitch of the sound. Frequency is used in audiometric testing to determine the levels of intensity that an individual can hear.
- The loudness of a sound is related to the amplitude of the wavelength; its unit is a decibel (dB). On the other hand, sound intensity is the rate of the flow of sound energy across a unit area. It is directly proportional to the square of the amplitude of the sound wave (Dawson et al.). The degree of the sensation of sound produced in the ear depends on the intensity and the ear’s sensitivity. In contrast, the intensity of sound is not dependent on the sensitivity of the ear. In audiometric testing, the intensity determines the rate at which an individual can hear a particular frequency.
Question #3
- A dB is a measurement of a logarithmic unit that is used to demonstrate the magnitude of sound in relation to a level of reference (Bauman). A decibel scale is used to figure out the loudness of a sound
- A dB SPL (decibel sound per pressure) describes the extent at which sound molecules in the air are displaced. In audiology, dB SPL helps in measuring hearing loss. For instance, a person with hearing problems cannot perceive sounds at a lower frequency unless it has much as dB SPL.
- A dB HL (decibel in the hearing level) refers to the level of the decibel in the audiometer. The reference level of a dB HL is 0, and this level is related to the dB SPL average threshold. dB HL also measures the level of hearing at a particular frequency and dB SPL. Therefore, the scale is essential in calibrating the audiometer.
- A dB SL (decibel sensational level) implies the number of decibels above another threshold. The scale determines the threshold of loudness to ensure that the audiometer does not produce an extremely loud sound that is discomforting to the person.