Mobile Digital Recording: Adequacy of the iRig and iOS Device for Acoustic and Perceptual Analysis of Normal Voice.

OBJECTIVE: To determine whether the iRig and iOS device recording system is comparable with a standard computer recording system for digital voice recording. METHODS: Thirty-seven vocally healthy adults, between ages 20 and 62, with a mean age of 33.9 years, 13 males and 24 females, were recruited. Recordings were simultaneously digitalized in an iPad and iPhone using a unidirectional condenser microphone for smartphones/tablets (iRig Mic, IK Multimedia) and in a computer laptop (Dell-Inspiron) using a unidirectional condenser microphone (Samson-CL5) connected to a preamplifier with phantom power. Both microphones were lined up at an equal fixed distance from the subject's mouth. Speech tasks consisted of a sustained vowel "ah" at comfortable pitch/loudness, counting from 1 to 10, and a glissando "ah" from a low to a high note. The samples captured on the iOS devices were transferred via SoundCloud in WAV format, and analyzed using the Praat software. The acoustic parameters measured were mean, min, and max F0, SD F0, jitter local, jitter rap, jitter ppq5, jitter ddp, shimmer local, shimmer local-dB, shimmer apq3, shimmer apq5, shimmer apq11, shimmer dda, NHR, and HNR. RESULTS: There were no statistically significant differences for any parameter and speech task analyzed for both iOS devices as compared with the gold standard computer/preamp system (all P values > 0.050). In addition, there were no statistical differences in the perceptual identification of the recordings among devices (P < 0.001). CONCLUSION: In the present study, the iRig and iOS device may provide reliable digital recording of normal voices.

The Use of Sound Level Meter Apps in the Clinical Setting.

PURPOSE: The purpose of this study was to compare sound level meter (SLM) readings obtained using a Larson-Davis (Depew, NY) Model 831 Type 1 SLM, a RadioShack (Fort Worth, TX) SLM, and iPhone 5 (Apple, Cupertino, CA) SLM apps. METHOD: In Procedure 1, pure tones were measured in an anechoic chamber (125, 250, 500, 1000, 2000, 4000, and 8000 Hz); sound pressure levels (SPLs) ranged from 60 to 100 dB SPL in 10-dB increments. In Procedure 2, human voices were measured. Participants were 20 vocally healthy adults (7 women, 13 men; mean age = 25.1 years). The task was to sustain a vowel "ah" at 3 intensity levels: soft, habitual, and loud. Microphones were lined up equal distances from the participant's mouth, and recordings were captured simultaneously. RESULTS: Overall, the 3 SLM apps and the RadioShack SLM yielded inconsistent readings compared with the Type 1 SLM. CONCLUSION: The use of apps for SPL readings in the clinical setting is premature because all 3 apps adopted were incomparable with the Type 1 SLM.