A3FALL (Corpus of Acoustic Recordings of Fall Events)
This dataset contains a corpus of audio events corresponding to falls of several objects recorded in different conditions with an array of 3 aerial microphones and one Floor Acoustic Sensor (FAS). This database was designed and collected at the Università Politecnica delle Marche (UNIVPM), Ancona, Italy. A brief description of the database and its structure is reported in the following.
The dataset comprises recordings of fall events related to everyday objects and to "Rescue Randy", a human mimicking doll by Simulaids. The objects and the number of files per object are shown in the following table.
|OBJECT||Nr. OF FILES|
Objects were dropped at four distances from the sensors, 1 m, 2 m, 3 m, and 4 m, and with different angles. With the exception of the chair and the basket, which have been overturned from their natural position, half of the falls were performed at a height of 0.5 m and the other half at 1 m. The doll was dropped from upright position and from a chair.
The entire database was recorded using the Presonus AudioBox 44VSL soundcard, and the AKG C400 BL microphone used both in the array that in the FAS.
Two loudspeakers were used to reproduce the classical and rock audio tracks, then captured by the FAS and the array, which were then digitally added to the fall events (see below).
Floor Acoustic Sensor
The Floor Acoustic Sensor (Olivetti, P. (2015). Italian Patent 0001416548, July 1) is composed of a resonant enclosure and a microphone located inside it. At the bottom of the enclosure, a membrane is in direct contact with the floor and guarantees the acoustic coupling with the surface. The inner container accommodates the microphone and is where the acoustic resonance phenomenon takes place. It can be covered by a layer of acoustic isolation material and it is enclosed by the outer container that further reduces the intensity of the acoustic waves that propagate through air.The enclosure has been manufactured in Polylactic Acid with a 3D printer, its diameter is 16.5 cm and its height 5.5 cm.
Regarding the microphone, an AKG C 400 BL has been inserted in the enclosure. The outer case of the microphone has been removed to extract the capsule that has then been inserted in the sensor enclosure. The AKG C 400 BL is characterized by an hypercardiod directivity pattern, thus it has been oriented so that the maximum gain is towards floor.
The following are two examples of the dataset. They contain the recordings of the same fall event (the doll falling from upright position) acquired with the aerial microphone and with the floor acoustic sensor:
- rndy_d2st_free_0_fas: event recorded with the floor acoustic sensor;
- rndy_d2st_free_0_aer: event recorded with the aerial microphone.