De Lift

In a building in Amsterdam, an elevator inexplicably begins to function alone after a lightning storm causes a power failure, trapping four people in the elevator. The elevator will not open, even after a subsequent power restore and the passengers almost suffocate. Subsequent malfunctions prove fatal: an elderly blind man falls to his death when down the elevator doors open to an empty shaft, a night watchman of the building is decapitated by the elevator doors, and a janitor is snared in the shaft with his body dropping through the elevator ceiling hatch. Felix Adelaar, a technician from the elevator company Deta Liften, begins to examine the electrical system in an attempt to find any anomalies. During the course of several inspections, he meets journalist Mieke De Boer from The Nieuwe Revu, a local tabloid that Felix remarks he often finds in his friends' cat litter.When inspections reveal no apparent problems with the electrical system, Felix becomes obsessed with the continuing malfunctions of the elevator, not even taking pleasure in the occasional bowling with his wife Saskia and their mutual friends. Felix's continuing obsession causes Saskia to suspect that there may be another woman involved. Meanwhile, Felix continues his investigation by examining the manuals with wiring diagrams. When Felix pays yet another visit to the building he notices outside a van for Rising Sun, a manufacturer of microprocessors for automation (and a secret supplier of experimental microprocessors to Deta Liften). With Mieke's help, Felix collects the archives of newspaper articles about Rising Sun, and they decide to meet up with the head of the company. Mieke disguises herself as a co-worker and with Felix, tries to get information on the manufacturing process of the microprocessors and their possible faulty behavior. The director of the company gets nervous and answers abruptly, making very little time for the interview.Felix's wife finds out about his spending time with Mieke and fearing infidelity, angrily confronts him at dinner. Their argument is interrupted by a call from Mieke who invites Felix to meet with her former university professor who specializes in electronics. The professor explains microprocessors' sensitivity to external factors such as electric fields, magnetic fields, radioactivity, etc., which undermine the proper functionality and tells about a computer built years ago which had suddenly begun to self-program and went out of control.The next morning, Felix is summoned to the elevator factory by his boss who angrily suspends him for his unauthorized visit to Rising Sun. That evening, the owners of Deta Liften and Rising Sun have a secret meeting in a car near the building with the problematic elevator. Both businessmen get nervous as their secret experiment of building an elevator controller out of organic material is getting out of hand and killing people.Felix's wife leaves with their children. Feeling that he doesn't have anything left in life, he decides to solve the elevator conspiracy once and for all and see the experiment for himself. He sneaks into the building at night time, where the lift reveals itself to have a sentient mind as it operates properly until he tries to access the shaft, at which point it crushes the chair he was using. He then goes to the top floor with the elevator machinery and finds the metal enclosure containing the microprocessor is empty. He enters the elevator shaft, climbing onto the carriage to inspect the shaft for the replacement chip by plugging into the emergency controls on the elevator roof, resulting the microprocessor sensing this and stops him. He sees a faintly pulsating box above so he climbs wires up to it, where he uncovers the cover plate and sees viscous sticky goo crawling around a silicon chip making the sound of a heartbeat. Unnerved, Felix attacks the gooey silicon chip with his screwdriver where in response, the microprocessor starts the elevator at high speed and attacks Felix with its counterweight. Felix falls but manages has to catch onto a ledge below a set of elevator doors. As the elevator car hovers above him, Felix furiously scrambles to open the doors from the floor below and tries to hoist himself out, but his hands slip on the glossy floor. Due to the continuous high-speed attacks of the elevator, the cables break apart and the car falls after Mieke reaches in and pulls Felix out.Rising Sun's CEO arrives and realizing that his experiment failed, pulls out a pistol and fires into the biocomputer to finally kill it. In its last burst of madness, the computer shoots one of the broken cables out of the shaft, dragging the CEO into the shaft and hanging him. A shaken Felix and Mieke decide to take the stairs. As they walk downstairs and the credits roll, the screen fades green and the biocomputer's heatbeat continues (possibly indicating that is still active).

Question: When the screen turns green the biocomputer continues what sound?
Answer: a heartbeat