RTÉ Radio 1's 9am slot is down 13,000 listeners in its average ratings, according to the latest round of Joint National Listenership Research (JNLR) figures.
The most recent book-on-book figures include the first three months of Oliver Callan's official tenure on the morning show, the last three months of Ryan Tubridy's incumbency and the six months in between that saw a rotating roster of hosts fill the seat.
However, Oliver Callan is the third most-listened-to show in the country with 330,000 listeners each weekday.
Book-on-book is a comparison of the average listenership for programmes across the four previous quarters (three-month periods).
Since this time last year, 53,000 additional listeners are tuning into RTÉ Radio 1 across the week, weekly listenership to RTÉ 2FM has increased by 77,000, and RTÉ lyric fm has an additional 22,000 listeners based on this time last year.
Commenting on the latest figures, RTÉ Deputy Director General Adrian Lynch said: "RTÉ radio services are continuing to connect with over two million Irish people each week across RTÉ Radio 1, with increases in weekly reach across RTÉ 2FM and RTÉ lyric fm demonstrating the ongoing power of radio and importance of public service broadcasting on the airwaves for Irish audiences."
RTÉ Radio 1 remains the only Irish station with a weekly listenership of over one million.
Morning Ireland is down by 17,000 listeners in this book, yet it remains Ireland's number one radio show, with 469,000 people choosing to start their day with RTÉ Radio 1.
Today with Claire Byrne remains steady at 341,000, The Louise Duffy Show is up 4,000 to 218,000 while News at One is down 5,000 to 301,000 book-on-book.
Liveline is slightly down by 2,000 to 301,000, The Ray D'Arcy Show has 181,000 listeners, which is down 5,000 while Drivetime is at 220,000, which is down 1,000.
Weekends have seen a huge jump in listeners turning their dial to RTÉ Radio 1 in this book.
On Saturdays, Countrywide is up 21,000 to 255,000, Playback is up 9,000 to 339,000, The Business is up 11,000 to 324,000, Saturday with Colm Ó Mongáin is up 20,000 to 242,000 and Saturday Sport/Doc on One is up 9,000 to 213,000.
On weekends, 352,000 listeners tune in to Brendan O'Connor on Saturdays, which is a gain of 10,000 since the last round of figures were released.
Sundays are just as strong with an extra 13,000 listening to Sunday Miscellany, which is an average of 321,000. Sunday with Miriam has jumped by 12,000 listeners to 304,000 and Sunday Sport has 213,000 people tuning in, which is up 3,000.
Brendan O'Connor is up by 12,000 to 355,000, making the Sunday instalment of his show the second most-listened-to show in the country.
Over on 2FM, Breakfast with Doireann, Donncha and Carl and The Jennifer Zamparelli Show are down slightly this book, 3,000 to 143,000 and 1,000 to 135,000, respectively.
The Tracy Clifford Show has gained 8,000 to 121,000 and Drive It with The 2 Johnnies is up 1,000 to 151,000.
At the weekend, Laura Fox is up 8,000 to 129,000 on Saturdays and by 5,000 to 120,000 on Sundays. Roz and Emma are down 2,000 to 124,000 on Saturdays and 8,000 to 97,000 on Sundays.
Dan Healy, Head of RTÉ Radio Strategy and RTÉ 2FM, said of the latest figures: "2FM continues to increase its audiences with a growing share of 15 to 34-year-olds. This was a great book for Tracy Clifford with strong growth both book-on-book and year-on-year. The 2 Johnnies and The Breakfast Show continue to consolidate recent audience gains.
"Doireann leaves 2FM Breakfast in great shape, and Laura Fox continues to grow her show across weekends. It is great to have an exceptionally talented team both on and off air and I am confident that 2FM will continue to perform well for the rest of the year."
Sinéad Wylde, Head of RTÉ lyric fm, added: "RTÉ lyric fm is committed to bringing a world of music to listeners, be it classical, traditional, jazz, film, and musicals. Having recently celebrated our 25th birthday on 1 May, we know that the station has become a cherished companion to many loyal listeners over the years and from this book we are delighted to welcome 22,000 new listeners who come to RTÉ lyric to listen to great music."
