Assertion: air horn's sound | /r/HasProperty | pleasant
Facets:
value: to the ear
type: OTHER
value: at normal sound levels
type: OTHER
Source sentences:
text: If the diaphragm is in good condition, the air pressure is set to factory specifications, and the trumpets are properly “tuned,” the horns will make a wave-like, melodious sound that at normal sound levels is pleasant to the ear.