I’ll be starting school in the Fall and am curious about the salary range of an Engineer. My major is Engineering with a concentration in Aoustics.
The National Society of Professional Engineers publishes a yearly salary survey on its website, http://www.nspe.org They interview a bunch of companies in all fields of engineering about their salary ranges for each of the professional levels. It’s pretty vague, though - the summary is broken down into fields (i.e., civil, mechanical, etc.). The summary is all that’s available for free unless you are an NSPE member.
There aren’t any Engineering degrees in North America in Acoustics, so most likely you are looking at Mechanical Engineering…yes?
Well…the NSPE salary survey may work for you. Internally, my company has composites of surveys of engineering salaries (they use it to determine what the bare minimum amount of raise they should give us each year will be. 
) So…I called down, and asked the HR people in my company what the starting salary here in Kansas/Missouri would be for a Mechanical Engineer to be hired in the Acoustics/Environmental area.
4-year degree, no FE exam - $33,000 to $40,0000 per year
4-year degree, FE exam passed - $34,000 to $41,000 per year.
4-year degree, FE exam passed, in top 25% of class - $36,000 to $44,000 per year.
I have a friend whose older brother just finished a PhD in acoustics. Maybe its not quite the same but for him the answer is:
alot – if you’re willing to design underwater missile tracking systems. ::shrug::
You might want to consider Architectural Engineering. As an engineer who specializes in heating ventilating and air conditioning systems, I can tell you that a background in acoustics is very beneficial. Architectural Engineers are generally not paid as well as most other engineers but we do ok. In addition, the demand far exceeds the supply so job security is higher than it is for many other types of engineers.