It's no accident that Apple chose a yellow icon for its walkie-talkie feature. I dug out my old (2002ish) Nextel with PTT (push to talk). It was all the rage back then... :
Child Of The 80s & 90s - Chirp sound of the Nextel made me feel so official | Facebook
Nextel Motorola i550 Plus (Read Description) | eBay
Speaker Microphone for the i682 Two Way Cellular Radio | Eventtone
Stream Nextel Direct Connect PTT Sounds by Mountain Dew | Listen online for free on SoundCloud
Nextel Chirp - YouTube
nextel chirp sound effect|TikTok Search
Chirp Chirp* NEXTEL | When Phones Were Fun | For a few years in America, it was tough to go a day in public without hearing a distinctive electronic “chirp.” By 2004,
Nextel Chirp Sound Effect - YouTube
Where you at? i730 Chirp phone. For all you youngins lol #i730 #boostm... | TikTok
That annoyed BEEP BEEP from NEXTEL phones in the 90s (sound in comments) : r/nostalgia
Motorola i560 Rugged Nextel Phone Announced - ecoustics.com
Motorola i530 Yellow Rugged Walkie Talkie Nextel or | Ubuy Finland