|
Work item:
|
P.501 Cor.1
|
|
Subject/title:
|
Chinese (CN) reference speech sample in P.501 Annex D
|
|
Status:
|
Consented on 2026-06-17
|
|
Approval process:
|
AAP
|
|
Type of work item:
|
Recommendation
|
|
Version:
|
New
|
|
Equivalent number:
|
-
|
|
Timing:
|
Not specified (Medium priority)
|
|
Liaison:
|
-
|
|
Supporting members:
|
-
|
|
Summary:
|
The Chinese (CN) reference speech sample in ITU-T Rec. P.501 (04/2025) Annex D led to considerably lower scores for G.711 encoding (approximately 0.3 MOS lower on average) than the other reference speech samples in Annex D, when evaluated with ITU-T P.863 NB (narrowband mode).
After some analysis, it was observed that the reason for the low score was due to the female sentence characteristics. Applying a high-pass filter with a cut-off frequency of 120 Hz to the female sentence moved the combined female-male Chinese reference sample closer to the average of the P.501 Annex D samples.
Corrected wave files in all bandwidths are replaced in the ITU-T Test Signal Database for Annex D of ITU-T P.501.
|
|
Comment:
|
-
|
|
Reference(s):
|
|
|
Historic references:
|
|
Contact(s):
|
|
| ITU-T A.5 justification(s): |
|
|
|
|
First registration in the WP:
2026-06-22 16:24:09
|
|
Last update:
2026-06-24 11:11:14
|
