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This paper presents an overview of the results obtained with different analysis techniques applied to long-range signal recordings of the acoustic event associated with the loss of the Argentinian submarine ARA San Juan that occurred on 15 November 2017 around 500 km off the coast of Chubut, Argentina. The published works including analyses of those signals have mainly considered the source geolocation. In contrast, this work is focused on the nature of the source that generated the registered signals. An inverse problem approach is followed for estimating some features of impulse-like sources through the application of spectral and cepstral analyses to a set of acoustic data associated with an unknown source. The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) detected an unusual hydroacoustic signal originating in the vicinity of the last known location of the ARA San Juan, reported as a hydroacoustic anomaly, at two of its hydrophone stations located at Ascension Island and Crozet Island, in the central Atlantic Ocean and the southern Indian Ocean, respectively. The analyses performed on the raw acoustic data provided by the CTBTO are also applied to the signals produced by an underwater explosion of a depth charge during a controlled experiment conducted by the Argentinian Navy in a nearby area on 1 December. The propagation effects along these very long-range paths (approximately 7000 km) are calculated using a range-dependent 2D underwater acoustic propagation model based on the resolution of the wide-angle parabolic equation. Results of exhaustive comparative analyses of the signals generated on 15 November and 1 December, together with comparisons between the energy spectral density of recorded and modelled signal levels, reinforce the hypothesis of at least two close and successive implosions with a time lag of 329 ms and a separation of approximately 38 m, with an azimuth to the north in accordance with the expected heading of the submarine. The values obtained are compatible with the submarine dimensions and the course over ground of the submarine towards Mar del Plata harbour. Finally, an optimization process is performed for estimating the depth of occurrence of the acoustic event related to the submarine loss. [ABSTRACT FROM AUTHOR]