A rifle fired in the confines of a house is almost certainly going to cause permanent hearing damage to you and anyone else in the room.
No more than a shotgun, given similar barrel length.
http://www.freehearingtest.com/hia_gunfirenoise.shtml
Table 1. SHOTGUN NOISE DATA (DECIBEL AVERAGES)
.410 Bore
28" barrel...............150dB
26" barrel...............150.25dB
18" barrel...............156.30dB
20 Gauge
28" barrel...............152.50dB
22" barrel...............154.75dB
12 Gauge
28" barrel...............151.50dB
26" barrel...............156.10dB
18" barrel..............161.50dB
Table 2. CENTERFIRE RIFLE DATA
.223, 55gr. Commercial load 18 _" barrel.....155.5dB
.243 in 22" barrel...........................155.9dB
.30-30 in 20" barrel.........................156.0dB
7mm Magnum in 20" barrel.....................157.5dB
.308 in 24" barrel...........................156.2dB
.30-06 in 24" barrel.........................158.5dB
.30-06 in 18 _" barrel.......................163.2dB
.375 — 18" barrel with muzzle brake...........170 dB
Table 3. CENTERFIRE PISTOL DATA
.25 ACP...........155.0 dB
.32 LONG..........152.4 dB
.32 ACP...........153.5 dB
.380..............157.7 dB
9mm...............159.8 dB
.38 S&W...........153.5 dB
.38 Spl...........156.3 dB
.357 Magnum.......164.3 dB
.41 Magnum........163.2 dB
.44 Spl...........155.9 dB
.45 ACP...........157.0 dB
.45 COLT..........154.7 dB
There doesn't seem to be a huge difference between shotgun, pistol, and rifle noise levels, although the sound spectrum is undoubtedly different. There is a correlation with caliber (e.g., .30-06 is louder than .223 and .357 is considerably louder than 9mm or .45). There's a tight correlation with barrel length (shorter is louder for any given caliber), but less correlation with velocity. For all the 7.62x39mm shooters out there, I'd assume the sound levels would be about the same as .30-30, which it resembles.
For those who don't grok decibels, it's a logarithmic scale (usually log10); a 3dB difference equals twice the radiated acoustic energy, and a 10dB difference is ten times the radiated acoustic energy. The ear perceives a 10dB difference as a doubling in volume, and IIRC the average person can just barely distinguish a 1dB difference. A car interior at highway speeds is 60-70 dB, a vacuum cleaner in the 80's to 90dB, I think, for perspective.
The upshot is, if you have to shoot in self-defense in an HD situation, you will probably suffer some degree of hearing damage, and pretty much any effective choice (carbine, shotgun, pistol) is equally likely to cause such damage, sans suppressor. But if low probability of hearing damage were the primary criterion for choosing an HD gun, we'd all be using .22 carbines with subsonic ammo.
And while some of the small caliber, high velocity rounds tend to actually penetrate less than handgun rounds, most rifle cartridges will exit your home with considerable energy.
A loaded brick-and-mortar exterior wall will stop most intermediate caliber rifle rounds (and our house is brick), but when I keep a carbine for HD, I load it with lightweight JHP's anyway. I'll trade a little gelatin penetration for less wall penetration in that caliber (which is the same tradeoff a shotgunner would be making in situations in which wall penetration were a concern).
I don't dispute that the shotgun is an HD weapon
par excellence, but I would argue that given intelligent load selection, a .223 carbine can also be.