article_snippet.sent: They say that while it had a terrifying apperance, it hearing was probably below average compared to birds living today.
article_snippet.sent: others claim that the animal probably also had a limited vocal range that was quite low frequency.
article_snippet.sent: the animal has also raised the prospect that bird may have even used low frequency sounds to help detect bird prey.
article_snippet.sent: Dr Federico Degrange, a palaeontologist at the Centre for Research in Earth Sciences and the University of Córdoba in Argentina, said: 'The mean hearing estimated for bird was below the average for living birds. '
article_snippet.sent: Dr Degrange told Mail Online the bird had a tracheobronchial syrinx - the structure that produces sound in birds - that was mainly made of cartilage and so the bird did not survived.
article_snippet.sent: Dr Degrange said: 'It is not possible then through this to know exactly what kind of sounds terror birds were capable of produce. '