Regular listeners will notice something missing from radio broadcasts, ABC Radio Sydney has turned off the pips, the series of beeps that played at the end of the hour, usually followed by the familiar sound of the news theme. The final pips were played on Thursday November 24. Once used by listeners to set their watches, the six short tones have been deemed unnecessary in the age of digital radio and smart phones.

ABC Radio Sydney manager Steve Ahern said the pips were being switched off in Sydney to coincide with the station’s 100th anniversary. “We thought if you’re going to mark a symbolic change between the wonderful history of the last 100 years, and the future history of the next 100 years, which will be different, digital, amazing. Why not do something like that?”

Originally called 2SB, then 2BL and 702, it was the first to broadcast in Australia launching November 23 1923, just a few weeks before 2FC, which would later become Radio National.

In those early broadcasts, they had a rather inventive way of telling listeners the time. “They stuck the microphone out the window at the top of the hour, quarter past, half past and quarter to, and they recorded the sound of the Sydney GPO clock chiming and they played that every quarter hour,” Mr Ahern explained. “That was the first time signal.”

The electronically generated pips were first played in the early 1940s.

“You had to lock them to the atomic clock, so they’re accurate.”

Atomic clocks monitor time by measuring frequencies of atoms and keep time to within a millionth of a second.

Each of the six pips lasts for half a second. After each pip, there is half a second of silence. The final pip occurs at the precise moment the hour strikes.

The machines that generate the iconic sound are nearing the end of their life span and are no longer being made.

They were once linked to an integrated timekeeping system, including the talking clock and Sydney’s Observatory, relied on by RAAF planes to synchronise their equipment and for navigating shipping routes.

But the technology of timekeeping has moved on.

“The harsh reality is that GPS overrides everything,” Sydney master clockmaker Andrew Markerink said. “I won’t miss [the pips]. When it’s not there, will we even notice that it’s not there?”

James Valentine won’t miss the “kind of irritating” beeps each hour. 

People who tune in via an app or online have already been listening to pip-free radio because the stream is delayed by a few seconds due to internet buffering so the timing would be off.  

Breakfast presenter James Valentine said an earlier attempt to phase out the pips about 20 years ago caused an outcry from listeners.

But this time he suspects most won’t miss it, including himself.

“It’s now irrelevant and kind of irritating and strange,” he said. “Why do we have this pipping sound going up to the clock?”

When the BBC decided to stop playing the pips on some channels, it commissioned a symphony orchestra to make a new piece of music incorporating pip-like sounds to be played ahead of news.

The last pips were played on ABC Radio Sydney’s AM band at 7pm Thursday.