In my collection of audiobook electronics I own a Sony WM-150 Portable Cassette Player used for some of the older audiobooks I still own. When it comes to portability for CD’s and MP3 CD’s I own a iRiver SlimX iMP-900 (INNO) CD player, and I use Sennheiser HD 595 headphones with a Headroom portable headphone amplifier for both the cassette and CD player. In the home I own a Sony CMT-DH7BT DVD Micro System with Bluetooth (Recently Introduced/Discontinued?), and a Sony DRBT50 Stereo Bluetooth Headset I don’t use the speakers. As a back-up stereo I own a Onkyo MC35TECH, and I use the same Sennheiser HD 595 with a Headroom Micro Amp. Then late at night I normally listen to old time radio using a Tangent Quattro Wi-Fi radio which I also use to listen to Power Records, and certain audiobook downloads off my computer. The only missing device is an MP3 player since I honestly do not know how to run those, and I like having a hard copy of the audiobook so I simply listen to them as describe above. On the road my car has a cassette player, and a normal CD player so mainly I listen to cassettes in the car.
"I do not know with what weapons World War III will be fought, but World War IV will be fought with sticks and stones."
-Albert Einstein