Acoustic Analysis of Voice

This tutorial will take you through the steps necessary to complete an acoustic assessment of voice - an integral component of the comprehensive, gold standard voice assessment. To begin, you should read the free, open-access article by ASHA. Many of the analysis settings and protocols used in this tutorial were pulled from the ASHA-recommended guidelines in that article. This article also outlines a description of the minimum requirements for assessment equipment, testing environment, and acoustic outcomes.  The equipment I will be using in this tutorial which you could consider using for your own acoustic analyses are: head-mounted, AKG, omnidirectional, condenser microphone ($165 USD); a pre-amp (~$120 USD); a connecting cable for the microphone and pre-amp ($75 USD); and a personal laptop compter. I have no financial conflict of interests for any of these pieces of equipment.

This tutorial will use Praat for the acoustic analysis software. Therefore, you should download and install the freeware program Praat (free!) prior to beginning this tutorial. 

Part 1: Preparing Praat's Default Settings 

Step-by-step instructions are outlined below, with an extended (15-minute) and an abbreviated (1-minute) video tutorial available for viewing.  If you are new to Praat, I recommend viewing the extended video tutorial, otherwise the abbreviated video covers the below information.

Part 2: Pre-Recording Sound Check and Sound Level Calibration 

A pre-recording sound check and sound level calibration is required immediately before each and every acoustic analysis assessment. Therefore, complete the below prompts immediately before beginning a voice sample recording with an examinee. Step-by-step instructions are outlined below, with a 6-minute video tutorial available for viewing below the written instructions.

Microphone Positioning

Pre-Recording Sound Check of Soft and Loud Vocalizations

Sound Level Calibration

Part 3: Voice Sample Recording

Now that you have completed the pre-recording sound check and the sound level calibration, you are ready to obtain the voice sample recording. ASHA recommends obtaining the following voice samples: 

Record all of the above in a single audio clip for Praat analysis. In addition to the above, I also recommend recoding the following voice tasks in the same audio file:


Recording the Voice Samples

Part 4: Analysis

Now that you obtained the voice recordings, you are ready to begin the formal acoustic analysis to obtain a variety of speech and non-speech acoustic voice measures. Step-by-step instructions are outlined below, with an 18-minute video tutorial available for viewing.

Non-Speech Acoustic Voice Measures

Mean Habitual F0, jitter (local; %), shimmer (local; %), HNR (dB)

Mean Habitual SPL (dB)

smoothed Cepstral Peak Prominence (CPPS)

Minimum F0, maximum F0, and F0 range


Minimum SPL (dB), maximum SPL (dB), and SPL range (dB)

Acoustic Analysis: Continuous Speech Voice Measures

Mean SPL (dB), Mean F0, F0 SD, CPPS


Acoustic Analysis: Acoustic Voice Quality Index (AVQI)


Maximum Phonation Time, S/Z ratio, Laryngeal Diadochokinesis


Acknowledgments: I'd like to thank Adrián Castillo-Allendes for supplying me with the AVQI script and his assistance in verifying the techniques described above.