Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Sony MDR-DS5100 Dolby Infared Wireless Advanced Headphone System (Silver) (Discontinued by Manufacturer)
Product feature: 5.1ch Digital surround headphone system, Processor + Headphone, The Dolby signals are encoded into the infrared wireless signal and decoded by the headphones for an astonishingly realistic 3-Dimensional sound, Based on psychoacoustic perceptual science associated with Head Related Transfer Functions (HTRFs), Based on the way that parts of your head obstruct sound, the sound is angled so that your brain perceives that sound is coming from the front, rear, sides and between - creating the sound field of a perfect listening room - with stereo headphones, Optical Digital input
Product brand: Sony
Target attributes: Connectivity
Answer: attribute: connectivity
value: wireless
source: product feature
attribute: connectivity
value: wireless
source: product title