Online opinions show that users don't find a certain type of blender (professional, countertop or personal) to be especially quiet. The list of the top rated models for this factor is a mix of all 3 styles. For this reason, the price range for the quietest blenders is very wide, with some models costing as little as $25 - and others topping the charts at $200 or more.
However, opinions do indicate that units with plastic jars tend to be quieter than those with glass jars. With some exceptions, low-wattage blenders (under 450w) are considered quieter than more powerful ones.
When it comes to brands, Breville takes the cake for low noise level. Waring Pro, however, rates low in this category.