Real-time segmentation of the temporal evolution of musical sounds

Since the studies of Helmholtz, it has been known that the temporal evolution of musical sounds plays an important role in our perception of timbre. The accurate temporal segmentation of musical sounds into regions with distinct characteristics is therefore of interest to researchers in the field of timbre perception as well as to those working with different forms of sound modelling and manipulation. Following recent work by Hajda (1996), Peeters (2004) and Caetano et al (2010), this paper presents a new method for the automatic segmentation of the temporal evolution of isolated musical sounds in real-time. We define attack, sustain and release segments using cues from a combination of the amplitude envelope, the spectro- temporal evolution and a measurement of the stability of the sound that is derived from the onset detection function. We conclude with an evaluation of the method

Explorations in Timbre

Timbre is the quality of sound that enables us to recognise different instruments. The most successful methods for automatic instrument recognition are performed using information from sound that does not mean anything to the musician and is not directly related to the perception of timbre. Instead we start with an attribute of sound that is known to affect the way we perceive timbre. Two such attributes are the harmonic content of the sound and the “envelope” which describes the way volume rises and falls. This thesis explored several methods for detecting envelopes for the purpose of timbre description. A tool was developed that allows a user to match a synthetic wave to recorded audio by adding and adjusting amplitude and frequency control points. The resulting synthetic wave sounds subjectively close to the real audio. This provides avenues for future psychoacoustic research