The sewage treatment plant (14): sludge heating
Sounds recorded in the building with heat exchangers which heat the sludge to a temperature of about 38oC. Heated sludge goes to…

Since 1941 Siemens has been producing telephones in the small town of Bocholt, Germany. Today there are still 550 workers making cordless telephones for Gigaset, which separated from Siemens in 2010.
In hall 50 Gigaset produces 8.000.000 cordless telephones per year, checks their quality and packages them until they are ready to be send to retailers: At the design centre they form the plastic cases of the phones. At the SMD-department large machines populate printed circuit boards (the telephone’s electronic core) and at the quality inspection all buttons and functions of the finished phones are being checked.
The Pematech (production company) Testing Station in this recording is used to check all buttons of the phone automatically. A tray with the cordless phone is transported into the machine where a pneumatic system pushes all the buttons and assesses their functionality. This produces the many clicking sounds you can hear.
As this recording was made during running production there are other sounds in the background like the voices of staff and the noise of other large machines.
Sound Recordist: Kathinka Engels
Photographer: Inke Pickhardt
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