Money Talks — But Less Well so over the Mobile Phone? The Persistence of the Telephone Voice in a 4G Technology Setting and the Resulting Implications for Business Communication and Mobile-Phone Innovation

Our study is a first step toward the innovative further development of mobile phones with special emphasis on optimizing them for business communication. Traditional landline phones and mobile phones up to 3G technology are known to trigger the so-called “telephone voice”. The phonetic changes induced by the telephone voice (louder speech at a higher pitch level) are suitable for undermining the perceived competence, trustworthiness and charisma of a speaker and can, thus, negatively influence business actions over the mobile phone. In a speech production experiment with 20 speakers and a subsequent acoustic speech-signal analysis of almost 15 000 utterances, we tested in comparison to a baseline face-to-face dialog condition, whether the telephone voice still exists in a technological setting of VoLTE 4G mobile-phone communication. In fact, we found that the typical characteristics of the telephone voice persist even under the currently best technological 4G standards and under silent communication conditions. Moreover, we identified further acoustic-phonetic parameters of the telephone voice, some of which (like a more monotonous intonation) further compound the problem of business communication over the mobile phone. In combination, the extended parametric picture and the persistent occurrence of the “telephone voice” even under quiet 4G conditions suggest that a speech-in-noise-like (i.e. Lombard) adaption is not the only and perhaps not even the primary cause behind the telephone voice. Based on this, we propose a number of innovations and R&D activities for making mobile-phone technology more suitable for business communication.