Historical clue formulations

• Send an instant message — 2026-08-18
• Online notification sound — 2024-11-15
• Internet speed-test signal — 2023-06-18
• Send an e-message to — 2022-07-10
• — — 2022-06-19
• ___-Pong — 2022-03-14
• Radar sound — 2021-08-09
• With 65-Across, another name for 37-Across — 2019-05-08
• Notification sound — 2017-12-16
• Contact briefly electronically — 2014-09-06
• Worrisome engine sound — 2014-03-04
• ___-Pong — 2014-01-06
• Radar sound — 2011-12-27
• With 57-Across, game that includes the starts of 17-, 29-, 48- and 64-Across — 2011-06-13
• Unwanted engine sound — 2010-06-02
• Worrisome engine sound — 2008-12-07
• ... a table tennis ball (with 45-Across) — 2008-12-02
• Worrisome engine sound — 2008-04-13
• Pinball sound — 2008-03-06
• Unwelcome auto noise — 2007-12-26
• Sonar sound — 2006-05-15
• Sonar pulse — 2005-08-14
• Bullet sound — 2003-09-27
• Engine sound — 2003-09-07
• Unwanted engine sound — 2003-03-10
• Engine knock — 2000-09-11
• Striking sound — 2000-09-01
• Engine sound — 2000-06-21
• Worrisome car sound — 2000-01-19
• Engine sound — 1998-10-18
• Ricocheting bullet sound — 1998-08-20
• Engine knock — 1997-11-05
• Engine knock — 1997-05-27