The　electric　vehicle　driveline　generates　less　vibration　and　noise　compared　to　a　conventional　internal　combustion　engine　vehicle,　making　it　harder　for　the　driver　to　perceive　the　vehicle＇s　operating　status　through　driveline　sounds,　thereby　diminishing　driving　engagement　and　experience.　To　compensate　for　the　absence　of　engine　sound　in　EV　drivelines,　Active　Sound　Design　(ASD)　technology　has　become　a　crucial　method　for　drivetrain　sound　enhancement,　with　sound　synthesis　algorithms　playing　a　key　role　in　this　process.　Although　pitch-shifting　algorithms　based　on　frequency　shift　principles　can　synthesize　engine　sounds,　they　suffer　from　spectral　leakage　and　stuttering　caused　by　sound　splicing.　To　address　these　issues,　a　pitch-shifting　synthesis　algorithm　(QCPS,　Quadratic　interpolation-based　Continuous　audio　sample　indexing　Pitch　Shifting　algorithm)　is　proposed　in　this　paper,　which　combines　a　quadratic　interpolation　method　with　a　continuous　audio　sample　indexing　strategy.　First,　the　frequency　shift　coefficient　of　the　sound　is　calculated.　Based　on　this　coefficient,　corresponding　sound　fragments　are　extracted　from　the　original　audio　and　processed　using　a　pitch-shifting　interpolation　method　to　generate　the　target　sound.　Then,　different　interpolation　methods　are　compared　for　their　impact　on　sound　synthesis　quality.　Meanwhile,　a　continuous　audio　sample　indexing　strategy　is　developed　to　ensure　seamless　sound　output.　Finally,　a　simulation　program　for　the　QCPS　algorithm　is　developed,　and　an　ASD　verification　test　bench　is　set　up　to　validate　the　sound　synthesis　performance　of　the　proposed　QCPS　algorithm.　The　results　show　that　the　proposed　pitch-shifting　synthesis　algorithm　exhibits　minimal　spectral　leakage　and　ensures　smooth　sound　splicing.　This　paper　provides　an　effective　solution　for　compensating　EV　powertrain　sound　and　enhancing　the　driving　experience.　©　2025　SAE　International　and　KSAE.