No, our headphone extension cables do not have shielding  - for a very good reason. A headphone cable is similar to a loudspeaker cable in that it carries a high power signal with relatively high current and low voltage from a low impedance source (amplifier) to a low impedance sink (i.e. the headphone drivers of 4 – 36 ohms). This contrasts with a line level interconnect (such as our Performance J2P) which carries a low power, single ended signal with fixed voltage at line level and only micro amps of current, to a high impedance sink (typically 10 kohms). In the latter case you do need shielding as the high impedance and single ended nature of the signal makes it very vulnerable to high voltage noise signals from outside the system and if the output impedance is low, such as with a phono cartridge, it can also be vulnerable to high current noise signals and in this instance a coaxial construction s called for. With headphone cables we have a different problem. The low impedance environment makes it naturally immune to external noise signals, as any voltage induced on the cable from external sources has no power to drive the speaker and is either shunted directly to ground or compensated for by the negative feedback of the amplifier. In a stereo headphone cable though the two channels are closely bound together within the same cable, so there is a risk of significant crosstalk between channels if the design is not carefully constructed. Therefore the ground return wire in the headphone cable which is shared by both channels  needs to be at least double the cross-sectional area of the sending wires within the cable. If this was extended around the wires to form a shield it would have a deleterious effect on the signal by greatly and unnecessarily increasing cable capacitance (which could cause distortion by affecting amplifier stability) and so it is lumped together to form a large and effective current sink for the cable and minimise crosstalk to inaudible levels.