Dr. Chris Hanning:

I will partly address the first question. It is not just a question of the absolute noise level but also a question of the character of the noise. A characteristic of wind turbine noise is that it is impulsive, like a dripping tap. The noise has similar characteristics to alarms in that it is intermittent. A fire alarm is designed to wake one up. This characteristic may be the reason turbine noise seems to wake people up.

With regard to low-frequency noise and infrasound, I will ask Mr. Bowdler to respond if the Deputy wants the actual numbers. Essentially, a low-frequency noise is a bass rumble. Infrasound is below the theoretical level of hearing. It does seem as if the ear can actually respond or react to noise we do not normally hear. It may depend on what other noise is around.