Like a wind instrument, the sound was created by a specially carved or perforated bulb of deer horn or wood attached to the tip.
The Chinese xiangjian (sometimes pronounced and written mingdi) was quite similar, and until the end of the Warlord Era were commonly used by bandits to announce the gang's approach.
The whistling sound was also believed to chase away evil spirits, and to alert friendly kami to lend their support.
This practice of the formal archery exchange likely died out gradually following the end of the Heian period, as war became less and less ritualized.
The arrows would also be sold at Shintō shrines as good luck charms, particularly around New Year's Day; simply carrying a kabura-ya, like a Hama Ya, is meant to serve as a ward against evil spirits.