Since 13th July 2015, I have written at least 5 times to HDB on the "machinery" noise as heard by my mom at her unit during the late hours. The corresponding HDB officer, Miss Ng NG_Si_Yu@hdb.gov.sg has replied me that they are looking into the matters. As on 2nd Nov 2015, there is still no reply on the raised issue. May I know is this matter is really being investigated by HDB officer? Needless to say, the "machinery" noise as faced by my mom has negatively affected her sleep, and her daily routine.