Would turbulence of blood flow through the aortic valve give rise to the first heart sound?

No. The heart sounds are caused by the closure of heart valves. The first heart sound is caused by the closure of the AV valves (tricuspid and mitral). The second heart sound is the result of the closure of the aortic and pulmonic valve after the completion of systole. Turbulence of blood flow through the aortic valve would cause a murmur (an abnormal heart sound) during systole.