This article introduces researh activities at multimedia signal processing laboratory. Research theme of OTA laboratory is development of signal processing technique and its application. Signals research object are speech signal, musical acoustic signal and biological signal. The aim of researches of musical acoustic is to realize automatic music dictation. In order to achieve this aim, analyzed musical information is tempo, fundamental frequency and chord. The aim of researches of speech signal is to realize a speech system which can keep the individulity of speaker. In order to achieve this aim, acoustic features which are related to the individuality of speaker and the emotion are investigated. The aim of researches of biological signal is to understand the fuman and to engineering. Investigated biological signals are EMG(Electromyogram) and ECG(Electrocardiogaram). Investigation of EMG relates to clarify the appropriate activity of facial muscles for flute and playing. Investigation of ECG relates to clarify the biological reaction caused by the degradation of communication quality.