Śrīmad-Bhāgavatam 11.17.26
అగ్న్యర్కాచార్యగోవిప్రగురువృద్ధసురాఞ్శుచి: ।
సమాహిత ఉపాసీత సన్ధ్యే ద్వే యతవాగ్ జపన్ ॥ ౨౬ ॥
agny-arkācārya-go-vipra-
[agny-arkaachaarya-go-vipra-]
guru-vṛddha-surāṣ śuciḥ
[guru-vriddha-suraash shuchih]
samāhita upāsīta
[samaahita upaaseeta]
sandhye dve yata-vāg japan
[sandhye dve yata-vaag japan]
Word-for-word
agni
—
the fire-god
arka
—
the sun
ācārya
—
the ācārya
go
—
the cows
vipra
—
the brāhmaṇas
guru
—
the spiritual master
vṛddha
—
elder respectable persons
surān
—
the demigods
śuciḥ
—
purified
samāhitaḥ
—
with fixed consciousness
upāsīta
—
he should worship
sandhye
—
in the junctions of time
dve
—
two
yata-vāk
—
observing silence
japan
—
silently chanting or murmuring the proper mantras..
Blended reading (Sanskrit + English inline)
agny-arkācārya-go-vipra-
agni
the fire-god
arka
the sun
ācārya
the ācārya
go
the cows
vipra
the brāhmaṇas
guru-vṛddha-surāṣ śuciḥ
guru
the spiritual master
vṛddha
elder respectable persons
surān
the demigods
śuciḥ
purified
samāhita upāsīta
samāhitaḥ
with fixed consciousness
upāsīta
he should worship
sandhye dve yata-vāg japan
sandhye
in the junctions of time
dve
two
yata-vāk
observing silence
japan
silently chanting or murmuring the proper mantras..
Purified and fixed in consciousness, the brahmacārī should worship the fire-god, sun, ācārya, cows, brāhmaṇas, guru, elderly respectable persons and demigods. He should perform such worship at sunrise and sunset, without speaking but by silently chanting or murmuring the appropriate mantras.
Gauḍīya Ācāryas
Viśvanātha Cakravartī Ṭhākura
Gauḍīya
Translation
He should worship the fire-god, sun, ācāryas, cows, brāhmaṇas, gurus, elderly persons and devatās at sunrise and sunset, without speaking but by silently chanting mantras.
He should perform worship at sunrise and sunset chanting silently. This implies that he can chant loudly during the noon sandhyā.
My note
Source: vedabase.io