This study focuses on noise challenges in apartments, specifically inter-household noise. It examines five noise reduction factors, with a focus on airtightness and sound insulation. Findings show significant variations in sound insulation at low frequencies, depending on construction methods. Common trends emerge at 25 Hz and 63 Hz across all factors. Elements like tin pipe, insulated pipe, and panel board enhance noise insulation through airtight construction, while switches 2 and 4 exhibit decreased performance. The study establishes a strong correlation between sound insulation and air tightness, particularly in the mid-frequency range (315 Hz to 2,000 Hz), suggesting potential use of mid-frequency data for effective air tightness analysis.