Maximal Ambient Noise Levels and Type of Voice Material Required for Valid Use of Smartphones in Clinical Voice Research

Jean Lebacq, Jean Schoentgen, Giovanna Cantarella, Franz Thomas Bruss, Claudia Manfredi, Philippe DeJonckere

Research output: Contribution to journalArticlepeer-review


Purpose Smartphone technology provides new opportunities for recording standardized voice samples of patients and transmitting the audio files to the voice laboratory. This drastically improves the achievement of baseline designs, used in research on efficiency of voice treatments. However, the basic requirement is the suitability of smartphones for recording and digitizing pathologic voices (mainly characterized by period perturbations and noise) without significant distortion. In a previous article, this was tested using realistic synthesized deviant voice samples (/a:/) with three precisely known levels of jitter and of noise in all combinations. High correlations were found between jitter and noise to harmonics ratio measured in (1) recordings via smartphones, (2) direct microphone recordings, and (3) sound files generated by the synthesizer. In the present work, similar experiments were performed (1) in the presence of increasing levels of ambient noise and (2) using synthetic deviant voice samples (/a:/) as well as synthetic voice material simulating a deviant short voiced utterance (/aiuaiuaiu/). Results Ambient noise levels up to 50 dBA are acceptable. However, signal processing occurs in some smartphones, and this significantly affects estimates of jitter and noise to harmonics ratio when formant changes are introduced in analogy with running speech. The conclusion is that voice material must provisionally be limited to a sustained /a/.

Original languageEnglish
Pages (from-to)550-556
Number of pages7
JournalJournal of Voice
Issue number5
Publication statusPublished - Sep 1 2017


  • Acoustics
  • Dysphonia
  • Noise
  • Recording
  • Smartphone

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Speech and Hearing
  • LPN and LVN


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