Investigating differences in lab-quality and remote recording methods with dynamic acoustic measures

TL;DR

This study compares lab-standard and remote recording methods for acoustic measures, finding that smartphone recordings are most similar to lab recordings and more reliable than Zoom-based methods for phonetic research.

Contribution

It introduces a quantitative comparison of various remote recording methods against lab standards using dynamic acoustic measures, highlighting the reliability of smartphone recordings.

Findings

F0 was reliably measured across all methods.

Intensity and formants showed non-linear differences that could not be easily corrected.

Smartphone recordings (AVR) closely resembled lab recordings (H6).

Abstract

Increasingly, phonetic research utilizes data collected from participants who record themselves on readily available devices. Though such recordings are convenient, their suitability for acoustic analysis remains an open question, especially regarding how the individual methods affect acoustic measures over time. We used Quantile Generalized Additive Mixed Models (QGAMMs) to analyze measures of F0, intensity, and the first and second formants, comparing files recorded using a laboratory-standard recording method (Zoom H6 Recorder with an external microphone), to three remote recording methods, (1) the Awesome Voice Recorder application on a smartphone (AVR), (2) the Zoom meeting application with default settings (Zoom-default), and (3) the Zoom meeting application with the "Turn on Original Sound" setting (Zoom-raw). A linear temporal alignment issue was observed for the Zoom methods over the course of the long, recording session files. However, the difference was not significant for utterance-length files. F0 was reliably measured using all methods. Intensity and formants presented non-linear differences across methods that could not be corrected for simply. Overall, the AVR files were most similar to the H6's, and so AVR is deemed to be a more reliable recording method than either Zoom-default or Zoom-raw.