How to say "beep" in Japanese

• ビープ
  nounThe katakana loanword for the beep sound itself; use it when you simply want to say that a machine beeped, though it is less common.
• ビープ音ビープおん
  nounLiterally 'beep sound': the tone a machine emits, as when an appliance or computer signals with a warning beep; use this for the sound itself rather than an imitation.
• ブー
  interjectionOnomatopoeia for a low, buzzy tone: a car horn's honk or the wrong-answer buzzer on a quiz show. As a 'beep' it suggests that low buzz rather than a crisp electronic pip.
• ピーピー
  noun, adverbOnomatopoeia for high-pitched sounds — birds, insects, pipes, children's whistles; as a beep it evokes a shrill, repeated pip rather than a single low tone.
• 発信音はっしんおん
  nounA telephone term: the tone heard on the line when you place a call. Its 'beep' sense is this telephony tone, so it is not the word for a machine's beep in general.

For the beep a machine emits, 「ビープ音」 (or the loanword 「ビープ」) is the straightforward choice; 「ブー」 and 「ピーピー」 imitate low buzzy and high piping sounds respectively, and 発信音 is the telephone's calling tone.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• ビープbeep
• ビープ音ビープおんbeep
• ブーbeep
• ぴーぴーpeep
• 発信音はっしんおんtone
• ピー音ピーおんbleep (esp. for censoring)
• ぷーhonk (e.g. of klaxon)