People often lose their hearing for high pitch sounds first while maintaining good hearing for low pitch sounds. The high pitch sounds are what provide the clarity for speech and the low pitch sounds provide the volume. This can cause issues understanding certain consonants sounds like “s”, “sh”, “f” and “th”. So you may hear some say the word “fin” but they said “thin”. If you notice these types of misunderstandings, it's time to have your hearing evaluated.