Multiple center, double-blind, randomized, placebo-controlled study to see if it is safe to give ACHN-490 Injection for 5 consecutive days, to measure plasma pharmacokinetics, and to determine lung penetration of ACHN-490 (measured in ELF-epithelial lining fluid)after a single dose of ACHN-490 Injection in healthy volunteers.

Inclusion Criteria:

• Men or Women
• Within normal weight limits
• In good health with normal routine laboratory results
• Willing to not use media players (such as MP3 players) or devices with ear pieces and avoid exposure to loud noises

Exclusion Criteria:

• No ongoing medical conditions such as heart disease, high blood pressure, asthma, diabetes, seizures, or kidney problems
• No problems with hearing or balance
• No previous injury or surgery to the ears
• No family history of hearing loss before the age of 65
• Not taking any medications other than birth control medication
• Smokers or use of tobacco products
• Recent blood donors
• No excessive alcohol intake or illegal substances
• No allergy to aminoglycosides (a type of antibiotic)