Tighten in any loose pieces on the muffler. Loose pieces allow air to escape, which can create a whistling sound or other noise. Use a screwdriver to tighten any screws and an adjustable wrench to tighten any bolts.
Lubricate the chain with chain-lubrication oil. If its chain is not lubricated, not only is a chainsaw dangerous to use, but it can make a squealing sound. Place chain-lubrication oil into the chainsaw's oil filter. Do not worry if oil drips into the chainsaw's case; this is normal.
Wear ear muffs. Gas-powered chainsaw noise can run between 106 and 117 decibels. Use ear muffs designed to protect ear drums from that much sound. Chainsaw manufacturers and third-party parts manufacturers sell ear muffs capable of muffling chainsaw noises.