Final answer:
A hearing loss of 40 dB HL can result in conversational sounds being very quiet but still understandable, while a 60 dB HL hearing loss at frequencies like 5000 Hz can cause difficulty understanding speech without loud amplification. This can particularly affect the perception of female voices, which are higher in pitch.
Step-by-step explanation:
According to Anderson and Marlin (2007), a hearing loss of 40 dB HL (decibels Hearing Level) can result in a person finding conversational sounds very quiet, though they can still understand them. When a person experiences a 60 dB HL loss, especially around the frequency where a female voice typically resides (for example, near 5000 Hz), they may only hear low frequencies and will struggle to understand speech without significant amplification. It further gets complicated with higher voices such as female voices which have higher characteristic frequencies. Therefore, individuals with this level of hearing loss will require more intense sounds to perceive speech, and even then, speech may appear indistinct.
Hearing loss can vary at different frequencies and intensities, and it is measured in phons or dB HL. The presence of a hearing loss, such as 40 dB HL or 60 dB HL, defines how much sound needs to be amplified for a person to perceive it as normal. Lower-intensity sounds will generally need to be amplified more compared to more intense sounds to avoid further hearing damage.