Why Plasma Display Panel does not work on High Altitudes?

We have just now studied that Plasma Display Panel consists of very microscopic cells and within each cell two glass panels are separated by a narrow gap in which neon-xenon gas is injected and sealed in plasma form. This neon-xenon gas expands at high altitudes due to low pressure and that is why the picture is distorted. The Plasma TV at high altitude also creates a slight buzzing noise, which is basically because of the increased power consumption and the corresponding increase in its cooling needs (its fan usage)