AT&T 'Hellophone'The Hell’o’phone is a heavily modified AT&T 100 model telephone that enables you to reach out and violently shake someone.

Two joysticks are connected to what I’ve come to call ‘tone’ and ‘screech’ while two SPDT switches toggle various effects and a knob (seemingly) controls the threshold of the audio input as well as the rate and depth at which the ‘tone’ is stuttered.

AT&T ‘Hellophone’