Bruit are high pitched.. Regardless..
Sounds such as bruit are caused by turbulent blood flow are pretty nonspecific on their own.
A loud high pitched sound could indicate a small amount of blood traveling at high velocity through a small space. Similar to air passing through a small hole vs a big hole. This would be very bad in. Carotid, but could be a very good,thing in someone with say.. A septal heart defect.
On the flip side a low pitched sound may be the opposite, not a worry in a carotid, but a big problem in a heart.
Orr.. A high pitched sound that lasts a long time could be the same as a low pitched one thats audible a short time. At least in terms of actual flow, they could be identical.
The reality: theres just no way to know what it is, or how severe it is, without further testing. Let the family doctor listen to it.. If it sounds interesting he can refer an ultrasound which will put the issue to rest.