Wikipedia tells me that my dial tone is two overlapping tones:
One tone sounds at 350 Hz.
The other tone sounds at 440 Hz.
Together they sound like this.
Meryl Streep and Chris Cooper, acting, claimed (implicitly) that the dial tone was this.
However, after careful research, I discovered that, while Chris Cooper is humming a note around 350 Hz, Meryl Streep is humming a note closer to this.
That’s about 276 Hz or about a C#/Db!¹
Movies, I’m through believing everything you do!