1hearing impairment; reduced ability to hear (medical hearing loss, ranging from mild to severe).
年を取ると難聴になる人が増える。
More people develop hearing loss as they age.
彼は突然の難聴で耳鼻科を受診した。
He visited an ENT clinic due to sudden hearing loss.
難聴の診断後、補聴器を勧められた。
After a diagnosis of hearing loss, he was recommended a hearing aid.
2poor reception (e.g., radio, TV) — when audio is unclear or reception is bad; also used figuratively.
山間部では携帯の電波が弱く、ラジオも難聴になることがある。
In mountainous areas, cell signals are weak and radio reception can be poor.
会場のスピーカーの調子が悪く、後ろの席では難聴だった。
The venue's speakers were malfunctioning, and it was hard to hear from the back seats.