On-axis sound pressure levels and sound power of normal speech for speech intelligibility, privacy and security

Hopkins, Carl ORCID: 0000-0002-9716-0793, Graetzer, Simone and Seiffert, Gary (2025) On-axis sound pressure levels and sound power of normal speech for speech intelligibility, privacy and security. In: Forum Acusticum 2025, 2025-6-23 - 2025-6-26, Malaga, Spain.

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Abstract

In room acoustics, assessment of speech intelligibility, privacy and security requires the on-axis sound pressure level and sound power level of speech at a normal vocal effort level. For open-plan offices, ISO 3382-3 quotes octave band sound pressure and sound power from 125Hz to 8kHz for unisex speech (an average of male and female speech) to represent speaking with a normal vocal effort. However, limited sound power data are available with phonetically balanced speech in one-third octave bands, particularly for male and female talkers below 160Hz where unisex speech may not be suitable. This paper reports anechoic measurements of normal speech (720 sentences) from 12 native British English speakers (six male, six female) in one-third octave bands from 63Hz to 20kHz thereby including the Extended High Frequency (EHF) range above 7kHz. Whilst male and female talkers are similar in the mid-frequency range, there is greater variation between individual talkers and between sentences in the low- and high-frequency ranges. Measured data are converted to octave bands for comparison with ISO 3382-3, ANSI S3.5 and EN 60268-16 to indicate which values may need reconsideration in the building acoustics frequency range.

Item Type:	Conference Item (Unspecified)
Divisions:	Faculty of Humanities and Social Sciences Faculty of Humanities and Social Sciences > School of the Arts
Depositing User:	Symplectic Admin
Date Deposited:	01 Aug 2025 10:25
Last Modified:	01 Aug 2025 10:25
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3193803