Qfyilyi

I believe in most English dialects soften is pronounced without a t sound. In some dialects, often is similar, but in others a t sound is quite evident in often.

I'm interested not only in which areas of the world fall into each camp, but also whether there has been a recent transition going on in the pronunciation of the t. In the American dialect I grew up with, the t was silent, but in the last 10 or 15 years it seems to the t sound has become frequent. It may even have become predominant, but perhaps my brain has only been registering the pronounced-t instances since they are dissonant to my ear. My impression comes mainly from American broadcast media.

For often Merriam-Webster marks the pronunciation with T with an obelus (÷), meaning

indicates that many regard as unacceptable the pronunciation variant immediately following: nuclear nü-kl-r, nyü-, ÷-ky-lr

The Random House dictionary says:

Often was pronounced with a t -sound until the 17th century, when a pronunciation without the [t] came to predominate in the speech of the educated, in both North America and Great Britain, and the earlier pronunciation fell into disfavor. Common use of a spelling pronunciation has since restored the [t] for many speakers, and today exist side by side. Although it is still sometimes criticized, often with a [t] is now so widely heard from educated speakers that it has become fully standard once again.

The Oxford Dictionary says:

Usage
When pronouncing often, some speakers sound the t, saying /ˈôftən/; for others, it is silent, as in soften, fasten, listen. Either pronunciation is acceptable, although /ˈôfən /
is more common.

"Often" is an example of spelling pronunciation. The history of often is sort of conflicted but most of the sites I found via Google pointed away from pronouncing the word with a /t/ sound.

Strangely, "soften" also falls into this category. The word is does not strictly have a /t/ sound and is traditionally pronounced ˈsôfən. I did again see references to a spelling pronunciation that included a /t/ but it was less common than those for "often".

To directly answer your question, "often" should nearly always rhyme with "soften". If you are going to pronounce one with a /t/ than the other should be said with a /t/ as well. And vice versa: If you leave the /t/ out in one, you should do so in the other.

I might hasten to add that often one softens one’s final t in derived compounds, lest it be fastened on too tightly and thus become obtrusive enough that one might well expect to be chastened for it.

That is, compare hasten < haste, often < oft, soften < soft, fasten < fast, and chasten < chaste. The addition of -en to a word ending in -st or -ft causes the t to be lost in elision. See also christen < Christ, moisten < moist. In all cases, the t disappears from pronunciation.

Regarding often, the OED says:

Pronunciation:
Brit. /ˈɒf(ə)n/ , /ˈɒft(ə)n/ , U.S. /ˈɔf(ə)n/ , /ˈɑft(ə)n/

Forms: ME offen, ME offtyn, ME oftin, ME ofton, ME oftun, ME oftyn, ME oftyne, ME ouften, ME– often, 15 hofen, 15 hoften, 15 offten, 19– affin (Irish English), 19– aften (Irish English); Sc. pre-17 ofen, pre-17 oftin, pre-17 17– aften, pre-17 17– often, 18 af’en, 18– affen. Comparative ME oftynar, ME oftynner, ME– oftener, 16 ofner, 16–17 oftner, 17 offner, 17 off’ner; also Sc. pre-17 oftner, pre-17 oiftner, pre-17 17– aftener, 19– af’ner. Superlative 15 oftnest, 15 oftneste, 16– oftenest, 17 oft’nest; also Sc. 19– aftenest. (Show Less)

Etymology: < ofte, variant of oft adv. + -(e)n, probably after selden, variant of seldom adv. and adj.

Often is less commonly used than oft until the 16th cent. Several orthoepists of the 16th and 17th centuries, including Hart, Bullokar, Robinson, Gil, and Hodges, give a pronunciation with medial -t-. Others, including Coles, Young, Strong, and Brown, record a pronunciation without -t-, which, despite its use in the 16th cent. by Elizabeth I, seems to have been avoided by careful speakers in the 17th cent. (see E. J. Dobson Eng. Pronunc. 1500–1700 (ed. 2, 1968) II. §405). Loss of t after f occurs in other cases; compare soften v., and also raft n.1, haft n.1, etc. The pronunciation with -t- has frequently been considered to be hypercorrection in recent times: see for example H. W. Fowler Mod. Eng. Usage (1926), s.v.

However, the histories of listen (< OE lysna, *hlysna) and glisten (< OE glisnian, glysnian) are different.

While the DARE will probably show where in the US "often" is pronounced with a 't', in my experience (representing West Coast, South, Midwest, and South East usage), the 't' is normally silent. I do routinely hear the 't' in "often" in Canadian English, where it may be a regionalism.

Curiously, such speakers do not pronounce the 't' in "soften," but it's quite normal for some English speakers to have contrasting pairs where others have homophones (e.g., "caught" vs "cot").

on Forvo.com there are 10 pronunciations of 'often'. The only one with a hard T comes from Texas and has several downvotes...
http://www.forvo.com/word/often/#en

Relatively small sample size, but seems to follow what others are saying here.

Here is Australia the silent t is common for both often and soften. Hard t occurs for often, but is very rare in soften.